i have a problem in treeview Additional information: Index was outside the bounds of the array. - C# Discussion Boards

How to make DataGridView scrolling smooth (flickers problem)?

Alex Dunlop3-Jan-21 6:15

3-Jan-21 6:15

I have a DataGridView in my project which loads hundreds of rows from SQL CE file. It contains colorful texts and comboboxes. I searched online and found some solutions. Many of them says that I need to use double buffer. One of those solutions was this:

public static class ExtensionMethods
{
   public static void DoubleBuffered(this DataGridView dgv, bool setting)
   {
      Type dgvType = dgv.GetType();
      PropertyInfo pi = dgvType.GetProperty("DoubleBuffered", BindingFlags.Instance | BindingFlags.NonPublic);
      pi.SetValue(dgv, setting, null);
   }
}

and:

this.dataGridView1.DoubleBuffered(true);

I use following reference:

using System.Reflection;

My problem is that: 1) DataGridView in above class gives CS0118 error (has red underline)
2) Where should I use

this.dataGridView1.DoubleBuffered(true);

modified 3-Jan-21 22:26pm.

Re: How to make DataGridView scrolling smooth (flickers problem)?

Maciej Los3-Jan-21 23:47

Maciej Los

3-Jan-21 23:47

Take a look at this article Double Buffering a DataGridview to find out out how to enable DoubleBuffered.

Re: How to make DataGridView scrolling smooth (flickers problem)?

Alex Dunlop4-Jan-21 5:46

Alex Dunlop

4-Jan-21 5:46

I pasted this code at the end of my code lines but IDE gives error.

public partial class myDataGridView : DataGridView
{
    public myDataGridView()
    {
        InitializeComponent();
        DoubleBuffered = true;
    }    
}

The CS0118 eror code for DataGridView
The CS0103 for InitializeComponent and DoubleBuffered
How can I solve the problem? Confused | :confused:

Re: How to make DataGridView scrolling smooth (flickers problem)?

Maciej Los4-Jan-21 6:34

Maciej Los

4-Jan-21 6:34

Based on this piece of code you provided, i can't tell you what is wrong. If you replaced your DataGridView control with myDataGridView, you should be able to use DoubleBuffered.

An alternative...
How to: Reduce Graphics Flicker with Double Buffering for Forms and Controls - Windows Forms .NET Framework | Microsoft Docs
Control.SetStyle(ControlStyles, Boolean) Method (System.Windows.Forms) | Microsoft Docs

Re: How to make DataGridView scrolling smooth (flickers problem)?

Alex Dunlop4-Jan-21 6:46

Alex Dunlop

4-Jan-21 6:46

I provided an screenshot:
Untitled — ImgBB[^]

Re: How to make DataGridView scrolling smooth (flickers problem)?

Maciej Los4-Jan-21 7:38

Maciej Los

4-Jan-21 7:38

Seems, you don't understand what this code is doing...

Please, read about Inheritance - C# Programming Guide | Microsoft Docs and Polymorphism - C# Programming Guide | Microsoft Docs

Tip:
Go to the designer of Main class. Find 2 lines of declaration of dataGridView1:

this.dataGridView1 = new DataGridView();
//and 
private DataGridView dataGridView1;

Above code means that you've created an instance of standard DataGridView.

But(!) you need to create an instance od myDataGridView!

this.dataGridView1 = new myDataGridView();
//and
private myDataGridView dataGridView1;

For further details, please see: Inherit from Existing Controls - Windows Forms .NET Framework | Microsoft Docs

Good luck!

Re: How to make DataGridView scrolling smooth (flickers problem)?

Maciej Los6-Jan-21 21:46

Maciej Los

6-Jan-21 21:46

If you would like to get "working" doublebuffered datagridview component, you can download necessary files from this repository: GitHub - losmac/DoubleBufferedDataGridView: DataGridView (DoubleBuffered = true)

Good luck!

i have a problem in treeview Additional information: Index was outside the bounds of the array.

Member 1376816331-Dec-20 6:05

Member 13768163

31-Dec-20 6:05

this is my code
====================

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace AccountsTree
{
    public partial class Form1 : Form
    {
        clsAccounts cls = new clsAccounts();
        public Form1()
        {
            InitializeComponent();
            
        }
      
        public void filltree()
        {
            treeView1.Nodes.Clear();
            DataTable dt = new DataTable();
            dt = cls.getAccounts();
            treeView1.Nodes.Add("0", "Accounts");

                foreach (DataRow dr in dt.Rows)
                {

                    TreeNode [] node = treeView1.Nodes.Find(dr["MainAccount"].ToString(), true);
                 
                   
                  if (node != null)
                    {


                        node[0].Nodes.Add(dr["AccountCode"].ToString(), dr["AccountCode"].ToString() + dr["Name"].ToString());
                      
                      
                        
                    }
                    

                  
            }
          
                 }

        private void button4_Click(object sender, EventArgs e)
        {
            filltree();
        }
    }
}

=====================
and this is my sql script

USE [master]
GO
/****** Object:  Database [tree]    Script Date: 12/31/2020 19:01:01 ******/
CREATE DATABASE [tree] ON  PRIMARY 
( NAME = N'tree', FILENAME = N'E:\MyProjects\AccountsTree\tree.mdf' , SIZE = 3072KB , MAXSIZE = UNLIMITED, FILEGROWTH = 1024KB )
 LOG ON 
( NAME = N'tree_log', FILENAME = N'E:\MyProjects\AccountsTree\tree_log.ldf' , SIZE = 1024KB , MAXSIZE = 2048GB , FILEGROWTH = 10%)
GO
ALTER DATABASE [tree] SET COMPATIBILITY_LEVEL = 100
GO
IF (1 = FULLTEXTSERVICEPROPERTY('IsFullTextInstalled'))
begin
EXEC [tree].[dbo].[sp_fulltext_database] @action = 'enable'
end
GO
ALTER DATABASE [tree] SET ANSI_NULL_DEFAULT OFF
GO
ALTER DATABASE [tree] SET ANSI_NULLS OFF
GO
ALTER DATABASE [tree] SET ANSI_PADDING OFF
GO
ALTER DATABASE [tree] SET ANSI_WARNINGS OFF
GO
ALTER DATABASE [tree] SET ARITHABORT OFF
GO
ALTER DATABASE [tree] SET AUTO_CLOSE ON
GO
ALTER DATABASE [tree] SET AUTO_CREATE_STATISTICS ON
GO
ALTER DATABASE [tree] SET AUTO_SHRINK OFF
GO
ALTER DATABASE [tree] SET AUTO_UPDATE_STATISTICS ON
GO
ALTER DATABASE [tree] SET CURSOR_CLOSE_ON_COMMIT OFF
GO
ALTER DATABASE [tree] SET CURSOR_DEFAULT  GLOBAL
GO
ALTER DATABASE [tree] SET CONCAT_NULL_YIELDS_NULL OFF
GO
ALTER DATABASE [tree] SET NUMERIC_ROUNDABORT OFF
GO
ALTER DATABASE [tree] SET QUOTED_IDENTIFIER OFF
GO
ALTER DATABASE [tree] SET RECURSIVE_TRIGGERS OFF
GO
ALTER DATABASE [tree] SET  DISABLE_BROKER
GO
ALTER DATABASE [tree] SET AUTO_UPDATE_STATISTICS_ASYNC OFF
GO
ALTER DATABASE [tree] SET DATE_CORRELATION_OPTIMIZATION OFF
GO
ALTER DATABASE [tree] SET TRUSTWORTHY OFF
GO
ALTER DATABASE [tree] SET ALLOW_SNAPSHOT_ISOLATION OFF
GO
ALTER DATABASE [tree] SET PARAMETERIZATION SIMPLE
GO
ALTER DATABASE [tree] SET READ_COMMITTED_SNAPSHOT OFF
GO
ALTER DATABASE [tree] SET HONOR_BROKER_PRIORITY OFF
GO
ALTER DATABASE [tree] SET  READ_WRITE
GO
ALTER DATABASE [tree] SET RECOVERY SIMPLE
GO
ALTER DATABASE [tree] SET  MULTI_USER
GO
ALTER DATABASE [tree] SET PAGE_VERIFY CHECKSUM
GO
ALTER DATABASE [tree] SET DB_CHAINING OFF
GO
USE [tree]
GO
/****** Object:  Table [dbo].[Accounts]    Script Date: 12/31/2020 19:01:03 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Accounts](
	[AccountID] [int] IDENTITY(1,1) NOT NULL,
	[AccountCode] [varchar](50) NOT NULL,
	[MainAccount] [varchar](50) NOT NULL,
	[Name] [varchar](100) NULL,
	[AccountType] [tinyint] NOT NULL,
	[Debit] [real] NULL,
	[Credit] [real] NULL,
 CONSTRAINT [PK_Accounts] PRIMARY KEY CLUSTERED 
(
	[AccountID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY],
 CONSTRAINT [IX_Accounts] UNIQUE NONCLUSTERED 
(
	[AccountCode] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountID'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountID'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=-1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountID'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=1800 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'كود الحساب' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DisplayControl', @value=N'109' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Format', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_IMEMode', @value=N'0' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=-1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'الحساب الرئيسى' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DisplayControl', @value=N'109' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Format', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_IMEMode', @value=N'0' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=2655 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'اسم الحساب' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DisplayControl', @value=N'109' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Format', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_IMEMode', @value=N'0' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountType'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountType'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=-1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountType'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'2 حساب رئيسى1   : حساب فرعى' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountType'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=-1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'مدين' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DisplayControl', @value=N'109' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Format', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_IMEMode', @value=N'0' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=-1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'دائن' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DisplayControl', @value=N'109' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Format', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_IMEMode', @value=N'0' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DefaultView', @value=0x02 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Filter', @value=NULL , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_OrderBy', @value=N'Accounts.AccountName' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Orientation', @value=NULL , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_TableMaxRecords', @value=10000 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts'
GO
/****** Object:  StoredProcedure [dbo].[selectAc]    Script Date: 12/31/2020 19:01:12 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
Create proc [dbo].[selectAc]
as
select * 
from
Accounts
GO
/****** Object:  Default [DF_Accounts_MainAccount]    Script Date: 12/31/2020 19:01:03 ******/
ALTER TABLE [dbo].[Accounts] ADD  CONSTRAINT [DF_Accounts_MainAccount]  DEFAULT ('') FOR [MainAccount]
GO
/****** Object:  Default [DF_Accounts_AccountType]    Script Date: 12/31/2020 19:01:03 ******/
ALTER TABLE [dbo].[Accounts] ADD  CONSTRAINT [DF_Accounts_AccountType]  DEFAULT ((2)) FOR [AccountType]
GO
/****** Object:  Default [DF_Accounts_Debit]    Script Date: 12/31/2020 19:01:03 ******/
ALTER TABLE [dbo].[Accounts] ADD  CONSTRAINT [DF_Accounts_Debit]  DEFAULT ((0)) FOR [Debit]
GO
/****** Object:  Default [DF_Accounts_Credit]    Script Date: 12/31/2020 19:01:03 ******/
ALTER TABLE [dbo].[Accounts] ADD  CONSTRAINT [DF_Accounts_Credit]  DEFAULT ((0)) FOR [Credit]
GO

=====================================

need fix for this error

Index was outside the bounds of the array.

Re: i have a problem in treeview Additional information: Index was outside the bounds of the array.

Richard MacCutchan31-Dec-20 6:15

Richard MacCutchan

31-Dec-20 6:15

You are using a value to access the elements of an array. The value is either negative, or greater than the index value of the last item. You need to use the debugger to catch the exception and find out why it happens.

Re: i have a problem in treeview Additional information: Index was outside the bounds of the array.

BillWoodruff31-Dec-20 23:05

BillWoodruff

31-Dec-20 23:05

fyi: the TreeNode [] returned by 'Find can never be null. However, in .NET 5, this method will throw an ArgumentNullException if the Key is null or empty: [^]

«One day it will have to be officially admitted that what we have christened reality is an even greater illusion than the world of dreams.» Salvador Dali

Re: i have a problem in treeview Additional information: Index was outside the bounds of the array.

Richard MacCutchan31-Dec-20 23:13

Richard MacCutchan

31-Dec-20 23:13

I think this message was meant for the OP.

Re: i have a problem in treeview Additional information: Index was outside the bounds of the array.

BillWoodruff1-Jan-21 0:00

BillWoodruff

1-Jan-21 0:00

no, Richard, it was meant for Thee.

«One day it will have to be officially admitted that what we have christened reality is an even greater illusion than the world of dreams.» Salvador Dali

Re: i have a problem in treeview Additional information: Index was outside the bounds of the array.

Richard MacCutchan1-Jan-21 0:24

Richard MacCutchan

1-Jan-21 0:24

I don't think I referred to that point in my response to OP; so I am a bit confused.

Re: i have a problem in treeview Additional information: Index was outside the bounds of the array.

Gerry Schmitz31-Dec-20 9:15

Gerry Schmitz

31-Dec-20 9:15

Maybe you should try .Count instead of null.

Quote:
The Count property holds the number of TreeNode objects assigned to the collection. You can use the Count property value as the upper bounds of a loop to iterate through a collection.

TreeNodeCollection.Count Property (System.Windows.Forms) | Microsoft Docs

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

Re: i have a problem in treeview Additional information: Index was outside the bounds of the array.

BillWoodruff31-Dec-20 22:58

BillWoodruff

31-Dec-20 22:58

You have confused the get-only Count Property of a TreeNodeCollection with the Count Method of an Array. Using the Length Property of the Array works fine.

Down-voted.

«One day it will have to be officially admitted that what we have christened reality is an even greater illusion than the world of dreams.» Salvador Dali

Re: i have a problem in treeview Additional information: Index was outside the bounds of the array.

Gerry Schmitz2-Jan-21 9:28

Gerry Schmitz

2-Jan-21 9:28

You got lucky.

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WCF Service doesn't return data

Member 1483009827-Dec-20 6:00

Member 14830098

27-Dec-20 6:00

Hello, i want to create simple mobile add using Xamarin who use WCF Service, but i have problem with return data from database.

Firstly i connect database with WCF and create code:

IServiceWhitewagon:

[ServiceContract]
    public interface IServiceWhitewagon
    {

        [OperationContract]
        List<CompanyForView> GetCompany();
    }

ServiceWhitewagon

public class ServiceWhitewagon : IServiceWhitewagon
   {
       public ServiceWhitewagon()
       {

       }

  public List<CompanyForView> GetCompany()
       {
           WhitewagonEntities db = new WhitewagonEntities();
           return
               (from company in db.Company
                select new CompanyForView
                {
                    idCompany = company.idCompany,
                    name = company.name,
                    phone = company.phone,
                    adress = company.adress
                }
                ).ToList();
       }
   }

CompanyForView

[DataContract]
    public class CompanyForView
    {
        [DataMember]
        public int idCompany { get; set; }

        [DataMember]
        public string name { get; set; }

        [DataMember]
        public string adress { get; set; }

        [DataMember]
        public string phone { get; set; }
    }

In next step i connect WCF with my app called AppMobileWhitewagon
Screen

While connect WCF I usinghttp://localhost:54308/ and i saw all created metod in WCF. Whats more i test WCF in WCT Test Client and i see data from datatable:
Screen

In MobileApp i have problem with show data from datatable. When in App I click on the button who should show card with data from datatable app freeze on 20 seconds and show empty card.

My code in class who should get data

public class CompanyDataStore : ItemDataStore<Company>
    {
        public CompanyDataStore()
        {
            items = zamowieniaServices.GetCompany(null).GetCompanyResult.Select(k => new Company
            {
                idCompany = k.idCompany,
                name = k.name,
                phone = k.phone,
                adress = k.adress
            }).ToList();
        }
    }

ItemDataStore

public abstract class ItemDataStore<T> : IDataStore<T>
    {
        public List<T> items;

        public IServiceWhitewagon zamowieniaServices { get; set; }

        public ItemDataStore()
        {
            zamowieniaServices = DependencyService.Get<ServiceReferenceWhitewagon.IServiceWhitewagon>();
        }
    }

I create 3 breakpoint in app:
Screen

App stop in first breakpoint, and when i Continue run code does not cause next breakpoint

P.S 1

I suppose that with my View is everythink ok, since when i change code in CompanyDataStore to this, app show data from this list

items = new List<Company>()
           {
              new Company{idCompany=1,name="Klient 1"},
              new Company{idCompany=2,name="Klient 2"},

           };

RegEx Not Properly Matching

#realJSOP26-Dec-20 3:07

#realJSOP

26-Dec-20 3:07

I'm trying to use regex to determine if a given stored proc body contains destructive sql clauses.

Here's my regex pattern (I want it to match if it contains a "select...from", but not match if it contains any of the destructive sql keywords shown):

"^(?=.*SELECT.*FROM)(?!.*(?:CREATE|DROP|UPDATE|INSERT|ALTER|DELETE|ATTACH|DETACH|TRUNCATE)).*$"

Here's the string I'm passing into the regex:

SQL

PROCEDURE [dbo].[GetAlertsForApp]
(
@appShortName nvarchar(16)
)
AS
BEGIN
SET NOCOUNT ON;
declare @appID int = (SELECT ID FROM dbo.Applications WITH(NOLOCK) WHERE AppShortName = @appShortName);
select [ID],[AlertName],[AlertTitle],[AlertMsg],[AlertStartDate],[AlertExpireDate],[AlertType],[AlertClassLevel]
,[AlertApps],[ActionName],[ControllerName],[DateAdded],[AddedByUMSUserID]
FROM [dbo].[Alerts] WITH(NOLOCK)
WHERE (UPPER(AlertApps) LIKE '%' + UPPER(@appShortName) + '%' OR UPPER(AlertApps) = 'ALL')
AND AlertExpireDate IS NULL OR AlertExpireDate > GETDATE() ;
END

My problem is that the regex does not result in a match. The string above does not contain any of the prohibited words, and does include a select statement. I'm confused, and maybe just a little bench blind (and not real experienced with regex)...

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-----
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-----
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Re: RegEx Not Properly Matching

OriginalGriff26-Dec-20 4:09

OriginalGriff

26-Dec-20 4:09

Try setting the RegexOptions.Multiline option to true: Without it the "$" will stop at the end of a line of input rather than the whole string.
Certainly if I set that on Expresso, it matches; without it it doesn't.

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Re: RegEx Not Properly Matching

#realJSOP26-Dec-20 4:26

#realJSOP

26-Dec-20 4:26

That doesn't always return the expected result. I did this and it works as expected:

string pattern1 = @"\b(SELECT)\b";
string pattern2 = @"\b(CREATE|DROP|UPDATE|INSERT|ALTER|DELETE|ATTACH|DETACH|TRUNCATE)\b";
Regex regex1 = new Regex(pattern1, RegexOptions.IgnoreCase);
Regex regex2 = new Regex(pattern2, RegexOptions.IgnoreCase);
bool match1 = regex1.IsMatch(query);
bool match2 = regex2.IsMatch(query);
result = match1 && !match2;

Regex hs always kinda baffled me, and I actively avoid using it unlesss it makes a lot more sense to use it.

Re: RegEx Not Properly Matching

OriginalGriff26-Dec-20 5:08

OriginalGriff

26-Dec-20 5:08

They are powerful, but it's too easy to get carried away! Laugh | :laugh:

Since you have a two regex solution, I'd probably stick with that - it's a load more understandable and maintainable than the equivalent single regex would be.

But ... I'd personally use a user ID with only SELECT permissions and say "stuff it - that'll do".

Re: RegEx Not Properly Matching

#realJSOP26-Dec-20 5:26

#realJSOP

26-Dec-20 5:26

In this particular case, I'm using that code to evaluate both a user entered query, and an existing stored proc that was pulled from the database.

It's for my entity factory article.

Re: RegEx Not Properly Matching

Richard Deeming4-Jan-21 22:28

Richard Deeming

4-Jan-21 22:28

OriginalGriff wrote:
I'd personally use a user ID with only SELECT permissions and say "stuff it - that'll do".

That wouldn't necessarily work. The caller might not have permission to delete from the table, but ownership chaining can bypass that.

Ownership chaining in SQL Server security feature or security risk[^]
Understanding SQL Server Ownership Chaining[^]

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- Homer

Re: RegEx Not Properly Matching

Gerry Schmitz26-Dec-20 14:54

Gerry Schmitz

26-Dec-20 14:54

The sql contains: SELECT ... FROM ... select ... FROM

Maybe it doesn't even see it as a SELECT.

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

Re: RegEx Not Properly Matching

jschell29-Dec-20 6:46

jschell

29-Dec-20 6:46

Some random comments.

1. Just noting that your database should probably provide the ability to preclude the db user from executing DDL commands, regardless of where they originate. So set up your application to only use users with appropriate permissions.

2. I suspect your regex should also use a boundary check ('\b') around the excluded word phrase.

3. If you allow dynamic SQL execution then someone could circumvent your check like: 'CR' + 'EATE'. Item 1 prevents that possibility also.

4. Allowing users to use SQL directly means you cannot protect the database absolutely. For example are users allowed to run "delete users" (no where clause)? Any protections added to protect against this can generally be circumvented.

5. Another problem with allowing user SQL is if the database contains large amounts of data users can end up writing very inefficient queries. Which can impact the entire enterprise. Not as much of a problem if each customer (and their users) are in a silo but a major problem if multiple customers exist on the same stack.

6. What about 'use'? Do you want users switching databases? Again something that 1 can prevent.

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