在WPF中添加和删除控件 [英] Add and Remove controls in a WPF

问题描述

我有一个wpf表单，当用户检查某个无线电控件时，我要在其中添加用户控件.如果未选中控件，则需要删除用户控件.

这是我正在尝试做的事情:

I have a wpf form where I am adding a user control when the user checks a certain radio control. If the control is unchecked then I need for the user control to be removed.

Here is what I was trying to do:

<pre lang="vb">Private Sub CtlRadioStacker1_rdYesChecked(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles CtlRadioStacker1.rdYesChecked<br />
    Dim cbMaterial As New ctlComboBoxStacker<br />
    If Me.CtlRadioStacker1.rdYes.IsChecked = True Then<br />
        cbMaterial.Name = "cbMaterial"<br />
        cbMaterial.Label.Content = "Material"<br />
        StackPanelMain.Children.Add(cbMaterial)<br />
    Else<br />
        Dim location As Integer = StackPanelMain.FindName("cbMaterial")<br />
        StackPanelMain.Children.RemoveAt(location)<br />
    End If<br />
End Sub</pre><br />

这段代码可以很好地添加控件，但是它并没有像我期望的那样删除控件.毫不奇怪，如果我切换单选按钮，它会添加控件的其他副本而不会删除最后一个控件，我知道这一点，并且在解决此难题后会予以纠正.

任何帮助将不胜感激.

谢谢，
Jason

This code adds the control just fine, however it does not remove the control as I had expected. Not surprisingly if I toggle the radio buttons it adds additional copies of the control while never removing the last, I am aware of this and will correct it once I solve this dilemma.

Any help would be greatly appreciated.

Thanks,
Jason

推荐答案

您应该改为在Unchecked事件中将其删除.
以下是两种解决方案，具体取决于用于标识要删除的控件的标准:

You should remove it in the Unchecked event instead I think.
Here''s two solutions, depending on what criteria for identifying the control to remove:

Private Sub RadioButton_Checked(sender As Object, e As RoutedEventArgs)

    Dim button As Button = New Button With {.Content = "Some content", .Name = "MyName"}
    theStackpanel.Children.Add(button)

End Sub

Private Sub RadioButton_UnChecked(sender As Object, e As RoutedEventArgs)

    ' Remove by control type, repeat if there can be many of the same type
    'theStackpanel.Children.Remove(theStackpanel.Children.Cast(Of UIElement).Where(Function(element) element.GetType() = GetType(Button)).First())

    ' Remove by control name
    theStackpanel.Children.Remove(theStackpanel.Children.Cast(Of FrameworkElement).Where(Function(element) element.Name = "MyName").Single())

End Sub

希望这会有所帮助，
Fredrik Bornander

Hope this helps,
Fredrik Bornander

这是怎么做的.假设要添加的UserControl在Grid资源中定义.

Here is how did. Assuming the UserControl to be added is defined in the Resources of Grid.

<grid name="grid">
<grid.resources>
    <local:ausercontrol x:key="myUserControl" xmlns:x="#unknown" xmlns:local="#unknown" />
</grid.resources>
<RadioButton Margin="28,29,0,0" Name="radioButton1" Height="16" HorizontalAlignment="Left" VerticalAlignment="Top" Width="120">RadioButton</RadioButton>
<StackPanel Margin="28,81,26,28" Name="stackPanel1"/>
<RadioButton Height="16" HorizontalAlignment="Right" Margin="0,29,38,0" Name="radioButton2" VerticalAlignment="Top" Width="120">RadioButton</RadioButton>
</grid>

在我的代码后面，我这样做了:

And in my code-behind, I did this :

public class Window1
UserControl uc;
    public Window1()
    {
        InitializeComponent();
        radioButton1.Checked += new RoutedEventHandler(radioButton1_Checked);
        radioButton1.Unchecked += new RoutedEventHandler(radioButton1_Unchecked);
    }
    void radioButton1_Unchecked(object sender, RoutedEventArgs e)
    {
        stackPanel1.Children.Remove(uc);
    }
    void radioButton1_Checked(object sender, RoutedEventArgs e)
    {
        uc = (UserControl)grid.FindResource("myUserControl");
        stackPanel1.Children.Add(uc);
    }
}

我添加了另一个radiobutton(radiobutton2)，以便可以为radiobutton1处理未经检查的事件.
这对您有用吗?

I have added another radiobutton(radiobutton2) so that the unchecked event can be handled for radiobutton1.
Did this work for you?

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