RoutedEvent Pass EventArg - WPF Discussion Boards

c# - programmatically add column & rows to WPF Datagrid - Stack Overflow

4-Feb-20 21:21

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: [WPF] Datagrid With Dynamic column

Richard Deeming5-Feb-20 0:48

Im new bie help me fix 1 erorr on wpf, i cant do it?

5-Feb-20 0:48

DataGrid.AutoGenerateColumns Property (System.Windows.Controls) | Microsoft Docs[^]
How to - Customize Auto-Generated Columns in the DataGrid Control - Windows Community Toolkit | Microsoft Docs[^]

NB: The built-in DataGrid control used to be provided as part of the "community toolkit". There may be some minor differences, but most articles that apply to the old community toolkit version will still apply to the built-in version.

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Member 1468037212-Jan-20 16:07

Member 14680372

12-Jan-20 16:07

I have set up the calculation program for the program, but now the problem is that I want to integrate the two classes together but it still is not compatible so you can help me! Textblock caculator not show Only one class can be implemented! code see here :

https://pastebin.com/AnKXHgvg?fbclid=IwAR3pEa1RjQrrvMNTq8wTfZNvmAwBJJehwf_6UoFK7h96lKSmpOZiatPGB9M

https://pastebin.com/qzPDwvzJ?fbclid=IwAR3dP3Ef3Lo2SSmk9sSLOzrCxy0tZC5Hczpl76SX8TmzdX2cFfr1RmWayhI

sql data :
https://i.stack.imgur.com/pCgiK.png[^]

Re: Im new bie help me fix 1 erorr on wpf, i cant do it?

Richard MacCutchan12-Jan-20 22:12

Richard MacCutchan

12-Jan-20 22:12

Please post proper details of your problem. People here cannot guess what your code is doing.

Re: Im new bie help me fix 1 erorr on wpf, i cant do it?

ZurdoDev13-Jan-20 1:07

ZurdoDev

13-Jan-20 1:07

Edit your question and post just the relevant code. Don't expect people to follow links to who knows what.

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Fight for left-handed rights and hand equality.

RoutedEvent Pass EventArg

Kevin Marois11-Jan-20 16:42

11-Jan-20 16:42

I have added a Routed Event to a user control:

public static readonly RoutedEvent ItemChangedEvent =
            EventManager.RegisterRoutedEvent("ItemChanged",
            RoutingStrategy.Bubble,
            typeof(RoutedEventHandler),
            typeof(DropDownEntryView));

public event RoutedEventHandler ItemChanged
{
    add { AddHandler(ItemChangedEvent, value); }
    remove { RemoveHandler(ItemChangedEvent, value); }
}

private void RaiseItemChangedEvent(string newValue, string oldValue)
{
    var args = new ItemChangedEventArgs(ItemChangedEvent, newValue, oldValue);
    RaiseEvent(args);
}

Here is the ItemChangedEventArgs class:

public class ItemChangedEventArgs : RoutedEventArgs
{
    public string NewValue { get; private set; }

    public string OldValue { get; private set; }

    public ItemChangedEventArgs(RoutedEvent routedEvent, string newValue, string oldValue)
        : base(routedEvent)
    {
        NewValue = newValue;
        OldValue = OldValue;
    }
}

The XAML

<ctrls:DropDownEntryView Grid.Column="0" 
                            Items="{Binding DataContext.EmailItems, 
                                            ElementName=clientsView,  
                                            Mode=TwoWay, 
                                            UpdateSourceTrigger=PropertyChanged}" 
                            EditBarCaption="Edit Emails..."
                            ShowEditBar="True"
                            ItemCategoryKey="email_types"
                            HorizontalAlignment="Left"
                            Width="400"
                            Margin="5">

<pre>
<i:Interaction.Triggers>
    <i:EventTrigger EventName="ItemChanged">
        <i:InvokeCommandAction Command="{Binding ElementName=clientsView, Path=DataContext.EmailItemChangedCommand}" 
                                CommandParameter="{Binding}"/>
    </i:EventTrigger>
</i:Interaction.Triggers>

How do I pass the ItemChangedEventArgs in the XAML?

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Gerry Schmitz11-Jan-20 20:24

11-Jan-20 20:24

I would load a list of user controls and use Property Changed instead. Less code.

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

Kevin Marois12-Jan-20 10:05

12-Jan-20 10:05

I'm developing some user controls. I want to be able to publish events and pass custom args

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Gerry Schmitz13-Jan-20 13:23

13-Jan-20 13:23

I add "actions" and "functions" to the controls that are wired at will:

public (static) Action<object, object=""> Hook = (o1, o2) => {};

...Hook = MyAction;

...
Hook( this, arg );

...
void MyAction( object sender, object arg ) { ... }

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

Kevin Marois14-Jan-20 5:18

14-Jan-20 5:18

I think I understand this. Can you show me an example of coding it in the usercontrol and how it's wired up in the parent window's XAML?

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Kevin Marois14-Jan-20 5:43

14-Jan-20 5:43

What do you think of the accepted answer here: c# - event Action<> vs event EventHandler<> - Stack Overflow ?

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Richard Deeming13-Jan-20 8:00

13-Jan-20 8:00

According to GitHub, if you don't set the CommandParameter or Converter properties, you should get the EventArgs passed to your command:
EventArgs as CommandParameter on InvokeCommandAction · Issue #126 · microsoft/XamlBehaviors · GitHub[^]

If that doesn't work, there are several alternatives suggested in this SO thread:
wpf - MVVM Passing EventArgs As Command Parameter - Stack Overflow[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois14-Jan-20 9:02

Calculate the textbox value based on the value of combobox ? ( wpf )

14-Jan-20 9:02

I resolved this using one of the workarounds you linked:

<TextBlock Grid.Row="2"
            Grid.Column="0"
            Text="Emails"
            Margin="5,10,5,5"/>
<ctrls:DropDownEntryView Grid.Row="3" 
                            Grid.Column="0"
                            Grid.ColumnSpan="2"
                            ItemCategoryKey="email_types"
                            HorizontalAlignment="Stretch"
                            Items="{Binding DataContext.EmailItems, ElementName=clientsView}"
                            ShowEditBar="True"
                            EditBarCaption="Edit Emails"
                            Width="400"
                            Margin="5">

<pre>
<i:Interaction.Triggers>
    <i:EventTrigger EventName="ItemChanged" >
        <cls:InvokeDelegateCommandAction Command="{Binding DataContext.EmailItemChangedCommand, ElementName=clientsView}"
                                            CommandParameter="{Binding RelativeSource={RelativeSource Self}, Path=InvokeParameter}" />
    </i:EventTrigger>
</i:Interaction.Triggers>

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Member 146803727-Jan-20 19:44

Member 14680372

7-Jan-20 19:44

I have a small program, because I'm new, my program is to bring data from sql sever to textbox via combobox option and use the value shown in that textbox to calculate the + I have made it to the step of putting up the data, now thanks to you to help me with the value calculation in the textbox, thank you for your help. 

xaml code :

 <Window.Resources>
        <local:SimpleMath x:Key="MyFriends"/>
    </Window.Resources>

    <Grid>
        <Label Content="code" HorizontalAlignment="Left" Margin="38,52,0,0" 
               VerticalAlignment="Top" Width="46" Height="23"/>
        <Label Content="pieces" HorizontalAlignment="Left" Margin="38,126,0,0" 
               VerticalAlignment="Top" Width="46" Height="23"/>
        <Label Content="layers" HorizontalAlignment="Left" Margin="38,196,0,0" 
               VerticalAlignment="Top" Width="46" Height="30"/>
        <Label Content="production pieces" HorizontalAlignment="Left" 
               Margin="0,278,0,0" VerticalAlignment="Top" Width="108" Height="25"/>
        <TextBox x:Name="txtcode" 
                 Text="{Binding Txtcode, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" 
                 HorizontalAlignment="Left" Height="23" Margin="124,52,0,0" 
                 TextWrapping="Wrap" VerticalAlignment="Top" Width="141"/>
        <TextBox x:Name="txtpieces" 
                 Text="{Binding Txtpieces, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" 
                 HorizontalAlignment="Left" Height="23" 
                 Margin="124,133,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="141"/>
        <TextBox x:Name="txtlayers" 
                 Text="{Binding Txtlayers,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" 
                 HorizontalAlignment="Left" Height="23" 
                 Margin="124,203,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="141"/>
        <TextBox x:Name="txtproductionpieces" 
                 Text="{Binding Txtproductionpieces,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" 
                 HorizontalAlignment="Left" Height="23" Margin="124,280,0,0" 
                 TextWrapping="Wrap" VerticalAlignment="Top" Width="141"/>
        <ComboBox x:Name="comboBox1" ItemsSource="{Binding Source={StaticResource MyFriends}}" 
                  HorizontalAlignment="Left" Margin="418,52,0,0" VerticalAlignment="Top" 
                  Width="319" Height="36" SelectionChanged="ComboBox1_SelectionChanged"/>
        <TextBox x:Name="txtseccond" 
                 Text="{Binding Txtseccond,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" 
                 HorizontalAlignment="Left" Height="23" 
                 Margin="124,345,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="141"/>
        <Label Content="seccond" HorizontalAlignment="Left" Margin="38,345,0,0" 
               VerticalAlignment="Top" Width="46" Height="23"/>
        <TextBlock Text="{Binding A, Mode=OneWay,UpdateSourceTrigger=PropertyChanged}" 
                   HorizontalAlignment="Left" Margin="418,133,0,0" TextWrapping="Wrap"  
                   VerticalAlignment="Top" Height="23" Width="248"/>
        <TextBox Text="{Binding No1,Mode=OneWay,UpdateSourceTrigger=PropertyChanged}" 
                 HorizontalAlignment="Left" Height="21" Margin="426,210,0,0" 
                 TextWrapping="Wrap" VerticalAlignment="Top" Width="303"/>
    </Grid>
</Window>


C# code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Data.SqlClient;
using System.ComponentModel;
using System.Runtime.CompilerServices;

namespace comboboxapp1
{
///

/// Interaction logic for MainWindow.xaml
///

public partial class MainWindow : Window
{
public SimpleMath Formular { get; set; }
public object SelectedValue { get; private set; }

public MainWindow()
{
Formular = new SimpleMath()
{
Txtcode = 0,
Txtpieces = 0,
Txtlayers = 0,
Txtproductionpieces = 0,
Txtseccond = 0,

};
InitializeComponent();
DataContext = Formular;
Fillcombobox();
}
private void MainWindow_Load(object sender, EventArgs e)
{

}
public void Fillcombobox()
{
SqlConnection con = new SqlConnection("Data Source=LEAN-22\\SQLEXPRESS;Initial
Catalog=LUAT;Integrated Security=True");

string sql = " select * from comboboxnew ";
SqlCommand cmd = new SqlCommand(sql, con);
SqlDataReader myreader;
try
{
con.Open();
myreader = cmd.ExecuteReader();
while (myreader.Read())
{
string sname = myreader.GetInt32(0).ToString();
comboBox1.Items.Add(sname);

}

}
catch (Exception ex)
{
MessageBox.Show(ex.Message);

}
}
public class SimpleMath : INotifyPropertyChanged
{
private int no1;

public int No1
{
get { return no1; }
set
{
no1 = value;
OnPropertyChanged("No1");
OnPropertyChanged("A");
}
}
private int txtcode;

public int Txtcode
{
get { return txtcode; }
set
{
txtcode = value;
OnPropertyChanged("Txtcode");
OnPropertyChanged("A");
}
}
private int txtpieces;

public int Txtpieces
{
get { return txtpieces; }
set
{
txtpieces = value;
OnPropertyChanged("Txtcode");
OnPropertyChanged("A");
}
}
private int txtlayers;

public int Txtlayers
{
get { return txtlayers; }
set
{
txtlayers = value;
OnPropertyChanged("Txtlayers");
OnPropertyChanged("A");
}
}
private int txtproductionpieces;

public int Txtproductionpieces
{
get { return txtproductionpieces; }
set
{
txtproductionpieces = value;
OnPropertyChanged("Txtproductionpieces");
OnPropertyChanged("A");
}
}
private int txtseccond;

public int Txtseccond
{
get { return txtseccond; }
set
{
txtseccond = value;
OnPropertyChanged("Txtseccond");
OnPropertyChanged("A");
}
}
public double A => No1;

public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged([CallerMemberName()] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
private void ComboBox1_SelectionChanged(object sender, SelectionChangedEventArgs e)
{

SqlConnection con = new SqlConnection("Data Source=LEAN-22\\SQLEXPRESS;Initial
Catalog=LUAT;Integrated Security=True");
// string sql = " select * from comboboxnew where code = '" + comboBox1.Text+ "';";
string sql = " select * from comboboxnew where code = '" + comboBox1.SelectedItem +
"';";
//Console.WriteLine(comboBox1.Text);
//MessageBox.Show(comboBox1.Text);
SqlCommand cmd = new SqlCommand(sql, con);
SqlDataReader myreader;
try
{
con.Open();
myreader = cmd.ExecuteReader();
while (myreader.Read())
{
string code = myreader.GetInt32(0).ToString();
string pieces = myreader.GetInt32(1).ToString();
string layers = myreader.GetInt32(2).ToString();
string productionpieces = myreader.GetInt32(3).ToString();
string seccond = myreader.GetInt32(4).ToString();
txtcode.Text = code;
//txtcode.Text =SelectedValue;
txtpieces.Text = pieces;
//txtpieces.Text = "New value";
txtlayers.Text = layers;
//txtlayers.Text = "New value";
txtproductionpieces.Text = productionpieces;
//txtproductionpieces.Text = "New value";
txtseccond.Text = seccond;
//txtseccond.Text = "New value";

}

}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
}

Re: Calculate the textbox value based on the value of combobox ? ( wpf )

Richard MacCutchan7-Jan-20 21:17

Richard MacCutchan

7-Jan-20 21:17

What is the problem, and where does it occur?

Re: Calculate the textbox value based on the value of combobox ? ( wpf )

Member 146803727-Jan-20 21:49

Member 14680372

7-Jan-20 21:49

https://www.upsieutoc.com/image/FSfuXK

Re: Calculate the textbox value based on the value of combobox ? ( wpf )

Richard Deeming8-Jan-20 0:46

Refresh Attached Property?

8-Jan-20 0:46

Member 14680372 wrote:

string sql = " select * from comboboxnew where code = '" + comboBox1.SelectedItem + "';";

Don't do it like that!

Your code is vulnerable to SQL Injection[^]. NEVER use string concatenation to build a SQL query. ALWAYS use a parameterized query.

Everything you wanted to know about SQL injection (but were afraid to ask) | Troy Hunt[^]
How can I explain SQL injection without technical jargon? | Information Security Stack Exchange[^]
Query Parameterization Cheat Sheet | OWASP[^]

private void ComboBox1_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    using (SqlConnection con = new SqlConnection("Data Source=LEAN-22\\SQLEXPRESS;Initial Catalog=LUAT;Integrated Security=True"))
    using (SqlCommand cmd = new SqlCommand("SELECT TOP 1 * FROM comboboxnew WHERE code = @code;"))
    {
        cmd.Parameters.AddWithValue("@code", Convert.ToString(comboBox1.SelectedItem));
        
        con.Open();
        
        using (SqlDataReader myreader = cmd.ExecuteReader(CommandBehavior.CloseConnection))
        {
            if (myreader.Read())
            {
                string code = myreader.GetInt32(0).ToString();
                string pieces = myreader.GetInt32(1).ToString();
                string layers = myreader.GetInt32(2).ToString();
                string productionpieces = myreader.GetInt32(3).ToString();
                string seccond = myreader.GetInt32(4).ToString();
                
                txtcode.Text = code;
                txtpieces.Text = pieces;
                txtlayers.Text = layers;
                txtproductionpieces.Text = productionpieces;
                txtseccond.Text = seccond;
            }
        }
    }
}

NB: You should avoid using SELECT * FROM ...; instead, specify the exact list of fields you want to load.

You'll need to check that Convert.ToString(comboBox1.SelectedItem) returns the value you're expecting. If it's a data-bound list, it might return something like "System.Data.DataRowView" instead, in which case you'll need to do some more work to get the real value.

And you should avoid hard-coding your connection strings. Store them in a configuration file instead. For example:
How to: Read Connection Strings from the Web.config File | Microsoft Docs[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois7-Jan-20 10:17

Re: Refresh Attached Property?

7-Jan-20 10:17

I created an AttachedProperty to handle enabling/disable UI elements based on a user's access rights:

public static class UIElementEnablerExtension
{
    public static string GetSecurityKey(DependencyObject obj)
    {
        return (string)obj.GetValue(SecurityKeyProperty);
    }

    public static void SetSecurityKey(DependencyObject obj, string value)
    {
        obj.SetValue(SecurityKeyProperty, value);
    }

    public static readonly DependencyProperty SecurityKeyProperty =
        DependencyProperty.RegisterAttached(
            "SecurityKey", typeof(string), typeof(UIElementEnablerExtension),
            new UIPropertyMetadata("", OnSecurityKeyPropertyChanged));

    private static void OnSecurityKeyPropertyChanged(DependencyObject d,DependencyPropertyChangedEventArgs e)
    {
        // If the current user has been set
        if (AppCore.CurrentUser != null)                   // AppCore is a static class
        {
            // Get the new value set in the XAML
            var accessKey = (string)e.NewValue;

            // If the key was set in the XAML...
            if (!string.IsNullOrEmpty(accessKey))
            {
                // Get the element
                var element = (UIElement)d;

                // Check the user to see if the access code is there
                var hasAccess = AppCore.CurrentUser.Rights.Any(x => x.CompareTo(accessKey) == 0);

                // Enable/Disable the element accordingly
                element.IsEnabled = hasAccess;
            }
        }
    }
}

Usage

<Button Content="Can Do Something"
        Command="{Binding MyCommand"}
        cls:UIElementEnablerExtension.SecurityKey="canUpdate"/>

The problem is that this fires long before the user is prompted to login. how cann I refresh this, or fire it again AFTER the user has logged in?

Or, does anyone have a better approach?

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

modified 7-Jan-20 16:59pm.

Richard Deeming8-Jan-20 1:18

WPF Exception - Send Error Report

8-Jan-20 1:18

As far as I can see, there isn't a way to get a list of elements with a particular attached property set. I suspect you'll need to maintain your own list, using the WeakReference<T> class[^] to avoid a memory leak.

Perhaps something like this?

public static class UIElementEnablerExtension
{
    private static readonly ReaderWriterLockSlim Locker = new ReaderWriterLockSlim();
    private static readonly List<WeakReference<UIElement>> TrackedElements = new List<WeakReference<UIElement>>();
    
    public static readonly DependencyProperty SecurityKeyProperty = DependencyProperty.RegisterAttached(
        "SecurityKey", typeof(string), typeof(UIElementEnablerExtension),
        new UIPropertyMetadata("", OnSecurityKeyPropertyChanged));
    
    public static string GetSecurityKey(DependencyObject obj) => (string)obj.GetValue(SecurityKeyProperty);
    
    public static void SetSecurityKey(DependencyObject obj, string value) => obj.SetValue(SecurityKeyProperty);
    
    private static void OnSecurityKeyPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (d is UIElement element)
        {
            Locker.EnterWriteLock();
            try
            {
                TrackedElements.Add(new WeakReference<UIElement>(element));
            }
            finally
            {
                Locker.ExitWriteLock();
            }
            
            EnableOrDisableElement(element);
        }
    }
    
    public static void OnCurrentUserChanged()
    {
        // Process a copy of the list, to avoid holding the lock for too long:
        List<WeakReference<UIElement>> elements;
        Locker.EntryReadLock();
        try
        {
            elements = new List<WeakReference<UIElement>>(TrackedElements.Count);
            elements.AddRange(TrackedElements);
        }
        finally
        {
            Locker.ExitReadLock();
        }

        var elementsToRemove = new List<WeakReference<UIElement>>();
        foreach (WeakReference<UIElement> item in elements)
        {
            if (item.TryGetTarget(out UIElement element))
            {
                EnableOrDisableElement(element);
            }
            else
            {
                elementsToRemove.Add(item);
            }
        }
        
        if (elementsToRemove.Count != 0)
        {
            // Remove any dead elements from the list:
            Locker.EnterWriteLock();
            try
            {
                foreach (WeakReference<UIElement> item in elementsToRemove)
                {
                    TrackedElements.Remove(item);
                }
            }
            finally
            {
                Locker.ExitWriteLock();
            }
        }
    }
    
    private static void EnableOrDisableElement(UIElement element)
    {
        string accessKey = GetSecurityKey(element);
        if (string.IsNullOrEmpty(accessKey))
        {
            element.IsEnabled = true;
            return;
        }
        
        bool hasAccess = AppCore.CurrentUser?.Rights.Any(x => string.Equals(x, accessKey, StringComparison.Ordinal)) ?? false;
        element.IsEnabled = hasAccess;
    }
}

You'll need to call UIElementEnablerExtension.OnCurrentUserChanged when the user logs in, either directly or using a mediator.

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois30-Dec-19 7:41

Re: WPF Exception - Send Error Report

30-Dec-19 7:41

I have an Exception Window dialog that I pop up when an error occurs. On it is a "Send Error Report" button that opens an email. I wrote out the Exception.ToString() to a file and attached it to the email.

I feel like this isn't enough info to accurately debug. So the question is, what else would you send?

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Richard MacCutchan30-Dec-19 10:13

Richard MacCutchan

30-Dec-19 10:13

Kevin Marois wrote:
what else would you send?

Stack trace, source code around the place that caused the exception, assuming you can capture such information. Really it is up to you to decide what information you would need in order to diagnose what went wrong.

Re: WPF Exception - Send Error Report

jimmson2-Jan-20 3:15

jimmson

2-Jan-20 3:15

Exception.ToString() doesn't usually give you the full picture. I usually recursively access the InnerException property and on each Exception level write down the exception type, message and stacktrace.

Re: WPF Exception - Send Error Report

Gerry Schmitz2-Jan-20 20:09