|
OleDbCommand cmd = new OleDbCommand();
cmd.CommandType = global::System.Data.CommandType.Text;
cmd.CommandText = "SELECT * FROM Table1 WHERE RFID = '" + textBox1.Text + "'";
cmd.Connection = myCon;
this.table1TableAdapter.Adapter.SelectCommand = cmd;
this.table1TableAdapter.Adapter.Fill(mdb11DataSet.Table1);
dgvConnect = new NominalRollDBConnection();
conString = Properties.Settings.Default.NominalRollCS;
dgvConnect.connection_string = conString;
dgvConnect.Sql1 = "SELECT * FROM NominalRoll WHERE RFID = '" + textBox1.Text + "'";
ds = dgvConnect.GetConnection1;
this.nominalRollTableAdapter.Fill(nominalRollDataSet.NominalRoll);
class NominalRollDBConnection
{
private string strCon;
private string sql_string1;
System.Data.SqlClient.SqlDataAdapter da_1;
public string Sql1
{
set { sql_string1 = value; }
}
public string connection_string
{
set { strCon = value; }
}
public System.Data.DataSet GetConnection1
{
get
{ return MyDataSet1(); }
}
private System.Data.DataSet MyDataSet1()
{
System.Data.SqlClient.SqlConnection con = new System.Data.SqlClient.SqlConnection(strCon);
con.Open();
da_1 = new System.Data.SqlClient.SqlDataAdapter(sql_string1, con);
System.Data.DataSet dat_set = new System.Data.DataSet();
System.Data.DataTable dat_table = new System.Data.DataTable();
da_1.Fill(dat_set, "Table_Data_1");
con.Close();
return dat_set;
}
I have a difference in output when using datagridview to display my data tables.
For the code above it outputs as per my query.
However for the second code it outputs the entire data table, can anyone please explain ?
Thank you 
edit: I have binded the datagridview using the GUI for the code above and below to respective datasources
modified 30-Nov-15 21:45pm.
|
|
|
|
|
Use the debugger to see exactly what command you are passing through, then look directly at the DB - without the data we would just be guessing what is in your two tables and text boxes.
But do yourself a favour: Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead.
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
|
|
|
|
|
OriginalGriff wrote: It leaves you wide open to accidental
I'd love to hear the excuse for accidentally dropping the user table, Little Bobby Tables is not an accident!
Never underestimate the power of human stupidity
RAH
|
|
|
|
|
Yeah, I know what you mean. But I like to presume Innocence instead of Guilt (unlike our current legal system) 
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
|
|
|
|
|
Hi, thanks for your help, I have tried using the debugger and it appears that for the code below it is not using my SQL query statements.
I have tried moving the query statements into the NominalRollDBConnection class and declaring the statements directly on my form part of the program but it still does not work.
I will try to resolve this via declaring all the SQL connections manually rather than use a separate class as now, am I headed the right way if I were to do this ?
Sorry if it looks as though as I am doing "crazy" things with the declarations. This is due to me being a total beginner to C# and my only prior lessons is very basic console applications using C++.
|
|
|
|
|
Member 12040781 wrote: cmd.CommandType = global::System.Data.CommandType.Text;
I know it's different to your original query but why are you setting the command type with a global reference to what is effectively an enum?
Every day, thousands of innocent plants are killed by vegetarians.
Help end the violence EAT BACON
|
|
|
|
|
..and why set it explicitly to its default value? 
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
|
|
|
|
|
Sorry, I did not have prior knowledge to enums, this is my first time using C#. From the example that I have on hand they're doing the declarations this way.
I will try to declare an enum class for the cmd object and see whether it will work.
|
|
|
|
|
Hello,when i start thread to plot in chart,but form is lose control, looks like thread is not in use.
private void button1_Click(object sender, EventArgs e)
{
Thread th=new Thread(new ThreadStart(fun1));
th.Start();
}
void fun1()
{
base.Invoke((MethodInvoker)delegate{
Series series1 = new Series();
for (int i = 0; i < 300; i++)
{
series1.Points.Add(new DataPoint(i, i));
Thread.Sleep(1000);
}
chart1.Series.Add(series1);
});
}
|
|
|
|
|
Ohm the thread works. The problem is that the code you're Invoking is being executed on the UI thread, not the thread you launched, because, well, THAT'S WHAT INVOKE DOES! And then you put the UI thread to sleep for a second. Once the Sleep is done and the delegate is done running, THEN you UI thread can get back to processing the message pump, like responding to WM_PAINT messages to repaint your window if needed.
You cannot touch a UI control properties or methods from anything other than the UI thread. You can create a new Series object and populate it with data in the background thread and THEN make the assignment to the chart object in delegated code. You're doing everything in the delegate, on the UI thread.
|
|
|
|
|
Hello, I have simply tried to create a static field on a class that will work like a counter for the instances ,but where I am trying to print the counter value is always on 0;
class Program
{
public static int Counter;
public Program()
{
Counter++;
}
static void Main(string[] args)
{
Program b;
Program c;
Console.WriteLine("{0}", Counter);
}
}
what is the problem ?
B.Is there a way to create a static var that is not field of the class and will work inside the class constructor (same idea as counter for the instances) ?
Thanks !
|
|
|
|
|
If you're talking about how many instances of your application are running, that's not going to work. You have to count the number of processes that are running using the process name of your application and the Process class.
If you're talking about how many instances of a class you have inside a single instance of a running application, that code may work.
|
|
|
|
|
I am talking just about the instances of the class,as in the answer below thanks !
|
|
|
|
|
There is no problem - the code is doing exactly what you've told it to! 
You increment the Counter variable each time you create a new instance of the Program class. However, you never create an instance of the Program class - you just declare two variables which could potentially hold an instance of that class in the future.
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
|
|
|
|
|
|
The problem is that in this case, you aren't creating any instances of your class, just the variables to hold instances. If Program was a struct rather than a class, then
Program b;
Program c;
would create instances - but they still wouldn't increment your counter, because value type constructions aren't implicitly called.
Try this:
Program b = new Program();
Program c = new Program();
And your counter will be incremented as you expect because you are creating instances.
A variable isn't the same as an instance: think of a variable as a "parking space" - it can hold any Car object, but you can't drive the space down to the shops! The parking space is the variable, the instance is the actual Car it holds.
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
|
|
|
|
|
OriginalGriff wrote: value type constructions aren't implicitly called.
Parameterless value-type constructors aren't allowed:
CS0568 Structs cannot contain explicit parameterless constructors
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
|
|
|
|
|
B.Is there a way to create a static var that is not field of the class and will work inside the class constructor (same idea, as counter for the instances) ?
|
|
|
|
|
class GlobalVariables
{
public static int Counter;
}
class App
{
public App()
{
GlobalVariables.Counter++;
}
}
static void Main(string[] args)
{
var a = new App();
var b = new App();
Console.WriteLine(GlobalVariables.Counter);
Console.ReadLine();
}
Needless to say that abusing it as a global variable is an anti-pattern. I don't know what you are trying to do, but this seems like the wrong way.
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
|
|
|
|
|
No: you have to something to "hold" the value, a Field, or a Property.
«I want to stay as close to the edge as I can without going over. Out on the edge you see all kinds of things you can't see from the center» Kurt Vonnegut.
|
|
|
|
|
A Console Application is not meant to be instantiated more than once; you need to separate out what you want to create multiple instances of from the Console App "framework:"
namespace ConsoleApplication1
{
class Program
{
public static int Counter = 0;
static void Main(string[] args)
{
SomeClass s1 = new SomeClass();
SomeClass s2 = new SomeClass();
}
}
public class SomeClass
{
public int MyID { set; get; }
public SomeClass()
{
MyID = Program.Counter++;
}
}
}
«I want to stay as close to the edge as I can without going over. Out on the edge you see all kinds of things you can't see from the center» Kurt Vonnegut.
|
|
|
|
|
hello every one,
I have a problem with my program,
I can select a image from one folder in open dialog but I can't move the image to be processed in another directory.
so pleas help me..
this is my program
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
namespace Dir
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private TransferFile transferFile = new TransferFile();
private void button1_Click(object sender, EventArgs e)
{
string cmd = "/c" + textBox1.Text;
System.Diagnostics.Process process = new System.Diagnostics.Process();
process.StartInfo.UseShellExecute = false;
process.StartInfo.FileName = "cmd.exe";
process.StartInfo.Arguments = cmd;
process.StartInfo.RedirectStandardOutput = true;
process.Start();
richTextBox1.Text = process.StandardOutput.ReadToEnd();
}
OpenFileDialog ofd = new OpenFileDialog();
private void button2_Click(object sender, EventArgs e)
{
string Filename = @"E:\MyDir";
string result;
result = System.IO.Path.GetFileName(ofd.FileName);
Console.WriteLine("GetFileName('{0}') returns '{1}'", Filename, result);
if (ofd.ShowDialog() == DialogResult.OK)
{
textBox1.Text = " RGBImage.exe " + System.IO.Path.GetFileName(ofd.FileName);
}
}
|
|
|
|
|
Make it easy by using what .NET provides:
using System.IO;
string f1 = @"C:\test1";
string f2 = @"C:\test2";
string fname = "someJPG.jpg";
private void MoveFile(string folder1, string folder2, string filename)
{
string filePath1 = Path.Combine(folder1, filename);
if ((!File.Exists(filePath1)) || (! Directory.Exists(folder2)))
{
throw new ArgumentException("invalid file or folder path");
}
try
{
File.Move(filePath1, Path.Combine(folder2, filename));
}
catch (Exception ex)
{
Console.WriteLine("{0} error moving file", ex.Message);
}
}
«I want to stay as close to the edge as I can without going over. Out on the edge you see all kinds of things you can't see from the center» Kurt Vonnegut.
|
|
|
|
|
hello,i have question as follows.
for example, I want to call fun1, then introduce vary x, and function as vary(fun2 or fun3), fun2 and fun3 have different varies. In fun1, can call fun2 or fun3 according to reference.
I think delegate can solve it ,but fun2 and fun3 have different number input, how to do it?
delegate void call() //?
main()
{
int x,y,z;
fun1(x,call)
}
fun1()
{
fun2(y) or fun3(y,z)?
}
fun2(int y);
fun3(int y,int z);
|
|
|
|
|
This code makes no sense: you call method 'fun1 with two arguments, but method 'fun1 takes no parameters. All your methods, and the delegate, are defined outside the scope of the Main method: what is the enclosing Class ?
«I want to stay as close to the edge as I can without going over. Out on the edge you see all kinds of things you can't see from the center» Kurt Vonnegut.
modified 30-Nov-15 4:45am.
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
