I have some controls where I set their Name property to unique names, but I am unable to access them in the matching C# code file.
I have tried:
this.ControlName
MainWindow.ControlName
ControlName
but it does "see" them.
How do I do this?
Also do I have to do something special for nested controls inside wrap panels, grid views, etc?
EDIT:
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
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.Reflection;
namespace EditorWindow
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow ( )
{
}
}
}
<Window x:Class="EditorWindow.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Effects Editor">
<DockPanel>
<ListView x:Name="EffectsListView">
</ListView>
</DockPanel>
</Window>
For accessing any element in code behind you will need to set x:Name directive.
It tells the XAML parser to add a field representing the named element to the automatically generated portion of the Window class just like Winforms.
In a WPF application, there’s no requirement to name each and every element. You should name only those elements which you want to programatically interact with.
An example:
<TextBlock x:Name="tblText" Text="Stackoverflow rocks."></TextBlock>
EDIT:
I used the following code and I was able to access the list view:
namespace WpfApplicationUnleashed
{
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
EffectsListView.Width = 10;
}
}
}
<Window x:Class="WpfApplicationUnleashed.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:sys="clr-namespace:System;assembly=mscorlib"
xmlns:local="clr-namespace:WpfApplicationUnleashed"
Title="Window1" >
<DockPanel>
<ListView x:Name="EffectsListView"></ListView>
</DockPanel>
</Window>
have you set their x:Name="ControlName" property in xaml?
Here is more information on x:Name directive.
For example:
<Button x:Name="Button1">Click Me</Button>
Related
This question already has answers here:
Why does WPF support binding to properties of an object, but not fields?
(2 answers)
Notify binding for static properties in static classes
(1 answer)
Closed 8 months ago.
I'm very new to C# and XAML. I'm trying to do a WPF project where there will be a good amount of data binding. Right now, I am able to do one way data binding without any problems, the issue I am facing is when I try to do two-way data binding.
This is the beginning of my Xaml file where I try to bind a text box to a static property in a static class:
<Window x:Class="interactive_fountain.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:interactive_fountain"
xmlns:include="clr-namespace:interactive_fountain.Include"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Grid>
<TextBox x:Name="ip_textBox" HorizontalAlignment="Left" Height="27" Margin="250,242,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="110" Text="{Binding Source={x:Static include:Communication.ipAddressServer}, Path=include:Communication.ipAddressServer, UpdateSourceTrigger=PropertyChanged}"/>
<Button Content="Button" HorizontalAlignment="Left" Margin="221,131,0,0" VerticalAlignment="Top" Height="47" Width="139" Click="Button_Click_1"/>
...
This is the beginning of the C# MainWindow Code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
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.Net;
using System.Net.Sockets;
using System.Diagnostics;
using interactive_fountain.Include;
namespace interactive_fountain
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void Button_Click_1(object sender, RoutedEventArgs e)
{
Trace.WriteLine("ip: " + Communication.ipAddressServer);
}
...
And this is the beginning of the class I want to do data binding with:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net;
using System.Net.Sockets;
using System.Diagnostics;
namespace interactive_fountain.Include
{
public static class Communication
{
public static string ipAddressServer = "hello";
...
Whenever I try to do two-way data binding, the place holder "hello" doesn't appear anymore. When I write in the textBox and press the button, the output will always be ip: hello no matter what I write in the box. I have looked at a lot of threads regarding this issue but I did not find a solution that worked for me.
Does anyone know how I could make it work?
Thanks in advance!!
WPF data binding works on public properties only, your ipAddressServer is a static field (aka class variable) and not a property, so it won't be used. It's also failing at following proper naming conventions.
Your mess of a binding is the old style static binding, use {Binding Path=(w:Communication.IpAddressServer)} instead (after you fix #1, of course). w is the relevant XAML namespace definition.
Static properties don't have standard notifications for change, since static classes can't implement interfaces (for what I hope are obvious reasons). Instead WPF uses a convention-based approach of using a public static event PropertyChangedEventHandler StaticPropertyChanged and call that to notify changes. It's not clear if you want your property to be mutable, but you mentioned the change notification mechanism explicitly, so just throwing it out there.
I am a complete "weekend warrior" to programming so go gentle on me, please...
I want to achieve a simple task, which I had no problem with in plain C# (TextBox.Text = "Something";)
I have a textbox and a textblock in XAML, and I want to populate them from C#, simple as that - run the web app and pull the predefined strings from the C# code. I have been searching for 2 days now and can't find a straight answer. I don't want any triggers (buttons), just filling e.g. textbox on load with a C# string. A simple code example on both XAML and C# side would be greatly appreciated!
Cheers,
Sasa
Not sure if I'm understanding your question...
<!--xaml-->
<TextBox x:Name="txtMyTextBox"/>
// C#
// Window constructor
public MyWindow()
{
InitializeComponent();
txtMyTextBox.Text = "Something";
}
One simple way to achieve what you try to achieve (if I understood correctly), is to add the UI elements to your window and set a Name for each of them. This way, you can access them in your code-behind as seen below.
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525" Loaded="Window_Loaded">
<Grid>
<TextBox Name="TextBox1" HorizontalAlignment="Left" Height="23" Margin="37,37,0,0" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="120"/>
<TextBlock Name="TextBlock1" HorizontalAlignment="Left" Margin="48,100,0,0" TextWrapping="Wrap" Text="TextBlock" VerticalAlignment="Top" Height="103" Width="239"/>
</Grid>
</Window>
While there are certainly more "refined" ways to achieve the same, once you named your UI elements in xaml, you can access them just as other object instances in your code-behind.
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;
namespace WpfApplication1
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void Window_Loaded(object sender, RoutedEventArgs e)
{
TextBox1.Text = "Hello TextBox1!";
TextBlock1.Text = "Hello TextBlock1!";
}
}
}
I am trying to use WPFToolkit in my user control dll. I inserted the WPFToolkit in its reference, and my user control dll builds with no error.
Then I insert my user control dll into my application, but when my application new an object of my user control dll
MultiROIStats mroi = new MultiROIStats();
the exception occured, saying:
Additional information: Could not load file or assembly 'WPFToolkit, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.
Here is my user control dll code, the constructor where the error occurs.
View xaml code:
<Window x:Class="MultiROIStats.MultiROIStats"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:dg="http://schemas.microsoft.com/wpf/2008/toolkit"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<dg:DataGrid ItemsSource="{Binding Path=FileData}" Margin="0,30,0,0" />
<Button Height="22" HorizontalAlignment="Left" Margin="8,4,0,0"
Name="button1" VerticalAlignment="Top" Width="48"
Command="{Binding Path=GetDataCommand}">Button
</Button>
</Grid>
</Window>
View 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;
namespace MultiROIStats
{
using System.Windows;
using ViewModel;
//xmlns:dg="clr-namespace:Microsoft.Windows.Controls;assembly=WpfToolkit"
/// <summary>
/// Interaction logic for UserControl1.xaml
/// </summary>
public partial class MultiROIStats : Window
{
public MultiROIStats()
{
InitializeComponent(); // exception occurs here!
DataContext = new MultiROIStatsViewModel();
}
}
}
I also checked the binary folder of my user control dll, the WPFToolkei.dll is there. So I am confused, and I am wondering how can I correct this error? Thanks.
Have you maybe tried the NuGet package for the toolkit to see if that works instead?
I know there is information about this on the internet and I've searched for it. But I'm still getting the error, can anyone point out to me what I'm doing wrong?
Base class:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Controls;
namespace ProgramManagementV2.screens
{
public abstract class AScreenUserControl : UserControl
{
public string GetScreenDescriptionName()
{
return "No name yet!";
}
}
}
MainUserControl.xaml
<UserControl x:Class="ProgramManagementV2.screens.MainUserControl"
xmlns:we="clr-namespace:ProgramManagementV2.screens"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<TextBlock Height="23" HorizontalAlignment="Center" Name="textBlock1" Text="asdfasdf" VerticalAlignment="Center" />
</Grid>
</UserControl>
MainUserControl.xaml.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
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.ComponentModel;
namespace ProgramManagementV2.screens
{
/// <summary>
/// Interaction logic for MainUserControl.xaml
/// </summary>
public partial class MainUserControl : AScreenUserControl
{
public MainUserControl()
{
InitializeComponent();
}
}
}
As you can see I'm adding
xmlns:we="clr-namespace:ProgramManagementV2.screens"
to the user control xml but I'm still getting the error:
Partial declarations of 'ProgramManagementV2.screens.MainUserControl' must not specify different base classes
Can anyone explain to me what I'm doing wrong?
By using <UserControl ... you claim the base-class to be UserControl, you would need to change it to
<we:AScreenUserControl x:Class="ProgramManagementV2.screens.MainUserControl" ...
However UserControls only allow one level of inheritance i think, at least if the AScreenUserControl has a XAML this surely will not work.
Just do this:
<we:AScreenUserControl x:Class="ProgramManagementV2.screens.MainUserControl"
xmlns:we="clr-namespace:ProgramManagementV2.screens"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<TextBlock Height="23" HorizontalAlignment="Center" Name="textBlock1" Text="asdfasdf" VerticalAlignment="Center" />
</Grid>
</we:AScreenUserControl>
I'm going round in circles here. I've kind of got the hang of XmlDataProvider bindings but the file I'm using seems too large to bind dynamically (50Mb doesn't work; 2Mb works). So instead I have the data loaded into classes using code generated from the XSD.
However, I can't get binding to CLR objects to work, due to my lack of knowledge. I'm using Visual Studio 2008 Pro, C# and .Net 3.5.
Here's the XAML file:
<Window x:Class="WpfObjectText.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfObjectText"
Title="Window1" Height="300" Width="300">
<Grid>
<Grid.Resources>
<ObjectDataProvider x:Key="simpleBinding" ObjectType="{x:Type local:ExampleClass}"/>
</Grid.Resources>
<StackPanel>
<TextBox Name="textBox1" Text="{Binding Path=simpleBinding}" />
</StackPanel>
</Grid>
</Window>
And the code behind:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
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;
namespace WpfObjectText
{
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class Window1 : Window
{
public ExampleClass TestInstance = new ExampleClass("Hello, world!");
public Window1()
{
InitializeComponent();
}
}
public class ExampleClass
{
public string TestString { get; set; }
public ExampleClass(string initialText)
{
TestString = initialText;
}
}
}
I've deliberately kept it simple so I can take baby steps. All I want to do here is populate the textbox from an instance of ExampleClass, and have the TestString field updated if the textbox changes (ie bidirectional). I know I can set MethodName in the binding which works to a certain extent in ListBoxes but that doesn't seem to imply bidirectional to me. Coming from a Delphi7 Win32 programmer, this is alien territory for me!
Assistance appreciated.
These are the necessary changes:
<TextBox Name="textBox1" Text="{Binding Path=TestString}" />
and then in the constructor:
DataContext = TestInstance;
If my understanding of the question is correct, you don't need Grid.Resources section at all.