C# WPF UniformGrid动态内容

我有一个uniformgrid，我想动态显示内容/视图。 它可以显示1、2、4或6个内容。我设置了uniformgrid行、列绑定和内容可见性绑定。 这在视图/内容的情况下不起作用， 但它在矩形的情况下确实有效。为什么呢？ 如何修改它以使用视图/内容。 示例MainWindow.xaml代码

<StackPanel>
    <ComboBox HorizontalAlignment="Left" Width="50" SelectedIndex="{Binding SelectedIndex}">
        <ComboBoxItem IsSelected="True" Content="1" />
        <ComboBoxItem Content="2" />
        <ComboBoxItem Content="4" />
        <ComboBoxItem Content="6" />
    </ComboBox>

    <!-- NOT CORRECT, SHOWS 6 ITEMS ALWAYS -->
    <UniformGrid Rows="{Binding ScreenRows}" Columns="{Binding ScreenCols}">
        <local:ScreenView Grid.Row="0" Grid.Column="0" Visibility="{Binding VisibleScreen[0]}" />
        <local:ScreenView Grid.Row="0" Grid.Column="1" Visibility="{Binding VisibleScreen[1]}" />
        <local:ScreenView Grid.Row="0" Grid.Column="2" Visibility="{Binding VisibleScreen[2]}" />
        <local:ScreenView Grid.Row="1" Grid.Column="0" Visibility="{Binding VisibleScreen[3]}" />
        <local:ScreenView Grid.Row="1" Grid.Column="1" Visibility="{Binding VisibleScreen[4]}" />
        <local:ScreenView Grid.Row="1" Grid.Column="2" Visibility="{Binding VisibleScreen[5]}" />
    </UniformGrid>

    <!-- OK, SHOWS 1,2,4, or 6 RECT DEPENDING ON SelectedIndex -->
    <UniformGrid Rows="{Binding ScreenRows}" Columns="{Binding ScreenCols}">
        <Rectangle Width="20" Height="20" Grid.Row="0" Grid.Column="0" Fill="Red" Visibility="{Binding VisibleScreen[0]}" />
        <Rectangle Width="20" Height="20" Grid.Row="0" Grid.Column="1" Fill="Orange" Visibility="{Binding VisibleScreen[1]}" />
        <Rectangle Width="20" Height="20" Grid.Row="0" Grid.Column="2" Fill="Yellow" Visibility="{Binding VisibleScreen[2]}" />
        <Rectangle Width="20" Height="20" Grid.Row="1" Grid.Column="0" Fill="Green" Visibility="{Binding VisibleScreen[3]}" />
        <Rectangle Width="20" Height="20" Grid.Row="1" Grid.Column="1" Fill="Blue" Visibility="{Binding VisibleScreen[4]}" />
        <Rectangle Width="20" Height="20" Grid.Row="1" Grid.Column="2" Fill="Violet" Visibility="{Binding VisibleScreen[5]}" />
    </UniformGrid>

</StackPanel>

基本上，我有一个组合框。如果选择1，我的ViewModel将动态更改rows=1、cols=1，第一个内容可见，其他内容将折叠。它适用于矩形，但不适用于视图。为什么呢？如何修复它以使其适用于视图

任何好奇的人，这里是MainWindowViewModel中的代码（Prism MVVM）

class MainWindowViewModel : BindableBase
{
    private const int SCREEN_MAX = 6;

    private int screenRows = 1;
    public int ScreenRows
    {
        get { return screenRows; }
        set { SetProperty(ref screenRows, value); }
    }

    private int screenCols = 1;
    public int ScreenCols
    {
        get { return screenCols; }
        set { SetProperty(ref screenCols, value); }
    }

    private Visibility[] visibleScreen = new Visibility[SCREEN_MAX];
    public Visibility[] VisibleScreen
    {
        get { return visibleScreen; }
        set { SetProperty(ref visibleScreen, value); }
    }

    private int selectedIndex;
    public int SelectedIndex
    {
        get { return selectedIndex; }
        set 
        { 
            SetProperty(ref selectedIndex, value);
            ChangeScreen(selectedIndex);                    
        }
    }

    private void ShowScreens(int num_screens)
    {
        // make all collapse
        for (int i = 0; i < SCREEN_MAX; i++)
            VisibleScreen[i] = Visibility.Collapsed;

        // show only X num screens
        for (int i = 0; i < num_screens; i++)
            VisibleScreen[i] = Visibility.Visible;

        RaisePropertyChanged("VisibleScreen");
    }

    public void ChangeScreen(int idx)
    {
        switch (idx)
        {
            case 0: ScreenRows = 1; ScreenCols = 1; ShowScreens(1); break;
            case 1: ScreenRows = 1; ScreenCols = 2; ShowScreens(2); break;
            case 2: ScreenRows = 2; ScreenCols = 2; ShowScreens(4); break;
            case 3: ScreenRows = 2; ScreenCols = 3; ShowScreens(6); break;
        }
    }
}

<UserControl...>
    <!-- SOME HOW IT IS THIS DATACONTEXT CODE MESS UP THE UI -->
    <UserControl.DataContext>
        <local:ScreenViewModel x:Name="vm"/>
    </UserControl.DataContext>
    <StackPanel>
        <TextBlock>TEST</TextBlock>
    </StackPanel>
</UserControl>

class MainWindowViewModel:BindableBase
{
专用常量int屏幕_MAX=6；
私有int screenRows=1；
公共整数屏幕行
{
获取{返回屏幕行；}
set{SetProperty（ref screenRows，value）；}
}
私有int screenCols=1；
公共int ScreenCols
{
获取{return screenCols；}
set{SetProperty（ref screenCols，value）；}
}
私有可见性[]visibleScreen=新可见性[SCREEN_MAX]；
公众能见度[]可视屏幕
{
获取{return visibleScreen；}
set{SetProperty（ref visibleScreen，value）；}
}
私有int-selectedIndex；
公共整数选择索引
{
获取{return selectedIndex；}
设置
{ 
SetProperty（参考selectedIndex，值）；
更改屏幕（选择索引）；
}
}
私有无效显示屏幕（int num_屏幕）
{
//崩溃
对于（int i=0；i

屏幕视图.xaml

class MainWindowViewModel : BindableBase
{
    private const int SCREEN_MAX = 6;

    private int screenRows = 1;
    public int ScreenRows
    {
        get { return screenRows; }
        set { SetProperty(ref screenRows, value); }
    }

    private int screenCols = 1;
    public int ScreenCols
    {
        get { return screenCols; }
        set { SetProperty(ref screenCols, value); }
    }

    private Visibility[] visibleScreen = new Visibility[SCREEN_MAX];
    public Visibility[] VisibleScreen
    {
        get { return visibleScreen; }
        set { SetProperty(ref visibleScreen, value); }
    }

    private int selectedIndex;
    public int SelectedIndex
    {
        get { return selectedIndex; }
        set 
        { 
            SetProperty(ref selectedIndex, value);
            ChangeScreen(selectedIndex);                    
        }
    }

    private void ShowScreens(int num_screens)
    {
        // make all collapse
        for (int i = 0; i < SCREEN_MAX; i++)
            VisibleScreen[i] = Visibility.Collapsed;

        // show only X num screens
        for (int i = 0; i < num_screens; i++)
            VisibleScreen[i] = Visibility.Visible;

        RaisePropertyChanged("VisibleScreen");
    }

    public void ChangeScreen(int idx)
    {
        switch (idx)
        {
            case 0: ScreenRows = 1; ScreenCols = 1; ShowScreens(1); break;
            case 1: ScreenRows = 1; ScreenCols = 2; ShowScreens(2); break;
            case 2: ScreenRows = 2; ScreenCols = 2; ShowScreens(4); break;
            case 3: ScreenRows = 2; ScreenCols = 3; ShowScreens(6); break;
        }
    }
}

<UserControl...>
    <!-- SOME HOW IT IS THIS DATACONTEXT CODE MESS UP THE UI -->
    <UserControl.DataContext>
        <local:ScreenViewModel x:Name="vm"/>
    </UserControl.DataContext>
    <StackPanel>
        <TextBlock>TEST</TextBlock>
    </StackPanel>
</UserControl>

试验

样本输出

正如您可以从示例输出中看到的，我的组合选择是1，所以它应该显示1个TEST，而1个正方形显示哪个是正确的。但为什么要让我看6级考试呢？如何让它显示1个测试

这是一个corect输出

---

谢谢

selectedIndex的初始值为0（int字段的默认值）。但是VisibleScreen数组的内容与selectedIndex不匹配-您需要在初始化期间调用ChangeScreen，例如：

public MainWindowViewModel()
{
    SelectedIndex = 0;
}

private void ShowScreens(int num_screens)
{
    for (int i = 0; i < SCREEN_MAX; i++)
        VisibleScreen[i].IsVisible = i < num_screens ? Visibility.Visible : Visibility.Collapsed;
}

顺便说一句，

Grid.Row

和

Grid.Column

在UniformGrid中无效。UniformGrid按项目添加的顺序排列项目

不要在UserControls内设置DataContext

而不是在MainWindowViewModel中创建的ScreenViewModel集合（

ObservableCollection

）

在

ScreenViewModel

中添加

bool IsVisible

属性

更改ShowScreens方法如下：

public MainWindowViewModel()
{
    SelectedIndex = 0;
}

private void ShowScreens(int num_screens)
{
    for (int i = 0; i < SCREEN_MAX; i++)
        VisibleScreen[i].IsVisible = i < num_screens ? Visibility.Visible : Visibility.Collapsed;
}

private void显示屏幕（int num_屏幕）
{
对于（int i=0；i

更改视图：

<ItemsControl ItemsSource="{Binding VisibleScreen}">
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
             <UniformGrid Rows="{Binding ScreenRows}" Columns="{Binding ScreenCols}"/>
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
    <ItemsControl.ItemTemplate>
        <local:ScreenView Visibility="{Binding IsVisible}"/>
    </ItemsControl.ItemTemplate>
</ItemsControl>

---

ItemTemplate将为VisibleScreen集合中的每个项目创建一个local:ScreenView，并将其分配给local:ScreenView的DataContext

不，它不起作用。我添加了你的建议，但结果仍然是一样的。当我在组合框中更改索引时，它仍然在屏幕上显示所有6个文本。如果我选择1，我期望的是1，而不是6。@Tim，我无法复制，我想不出来。我还有这个问题。您是否可以将您的解决方案共享给我？“您是否可以将您的解决方案共享给我”-我在VS中创建了新的WPF项目，从问号中复制了代码，并用PropertyChanged调用替换了

SetProperty

，因为我没有导入Prism包。这就是全部。Project targets.NET4.5.2Ok，我发现了问题。在我的ScreenView.xml中，我也有这样的代码，但是为什么这些代码会把UI搞得一团糟呢？？？这是非常标准的，我需要它来为我的视图模型做一些绑定。