WinUI 3：在 ContentDialog 打开时以编程方式更改 ContentDialog 大小

Question

我添加了两个按钮（一次仅可见一个）来调整 ContentDialog 的大小。我希望有两种尺寸：最大尺寸，其尺寸将调整为填充父窗口，或默认的“恢复”尺寸。它有点类似于标准 Windows 最大化和还原按钮。

我发现我可以在 XAML 中使用 ContentDialog.Resources 和“ContentDialogMaxWidth”和“ContentDialogMaxHeight”键来设置一种或其他所需的大小，如下所示。

XAML 中的默认大小：

<ContentDialog.Resources>
    <x:Double x:Key="ContentDialogMaxWidth">800</x:Double>
    <x:Double x:Key="ContentDialogMaxHeight">1000</x:Double>
</ContentDialog.Resources>

XAML 中的最大大小：

<ContentDialog.Resources>
    <x:Double x:Key="ContentDialogMaxWidth">2000</x:Double>
    <x:Double x:Key="ContentDialogMaxHeight">2000</x:Double>
</ContentDialog.Resources>

但是，上面的 XAML 仅在 ContentDialog 打开时设置一次大小。我似乎无法在打开后动态更改它。

下面是两个按钮的点击事件。我尝试在事件中动态更改上面显示的两个资源。即使资源值正在变化（我已经测试过），对话框大小也不会更新。

是否有另一种方法可以使用按钮事件将 ContentDialog 更改为所需的大小？

    private void MaximizeDialogButton_Click(object sender, RoutedEventArgs e)
    {
        this.FullSizeDesired = true;
        this.Resources["ContentDialogMaxWidth"] = 2000;
        this.Resources["ContentDialogMaxHeight"] = 2000;
        this.MaximizeDialogButton.Visibility = Visibility.Collapsed;
        this.RestoreDialogButton.Visibility = Visibility.Visible;
    }

    private void RestoreDialogButton_Click(object sender, RoutedEventArgs e)
    {
        this.FullSizeDesired = false;
        this.Resources["ContentDialogMaxWidth"] = 800;
        this.Resources["ContentDialogMaxHeight"] = 1000;
        this.Width = 800;
        this.Height = 1000;
        this.MaximizeDialogButton.Visibility = Visibility.Visible;
        this.RestoreDialogButton.Visibility = Visibility.Collapsed;
    }

Answer 1

似乎

ContentDialog

不支持这一点。相反，您可以使用 WinUIEx NuGet 包创建自定义对话框。

例如：

WindowDialog.xaml

<ex:WindowEx
    x:Class="WinUIDemoApp.WindowDialog"
    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:ex="using:WinUIEx"
    xmlns:local="using:WinUIDemoApp"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Grid RowDefinitions="*,Auto">
        <StackPanel
            Grid.Row="0"
            HorizontalAlignment="Center"
            VerticalAlignment="Center">
            <NumberBox
                x:Name="WidthNumberBox"
                ValueChanged="WidthNumberBox_ValueChanged" />
            <NumberBox
                x:Name="HeightNumberBox"
                ValueChanged="HeightNumberBox_ValueChanged" />
        </StackPanel>
        <Grid
            Grid.Row="1"
            ColumnDefinitions="*,*">
            <Button
                Grid.Column="0"
                Click="OKButton_Click"
                Content="OK" />
            <Button
                Grid.Column="1"
                Click="CancelButton_Click"
                Content="Cancel" />
        </Grid>
    </Grid>

</ex:WindowEx>

WindowDialog.xaml.cs

using Microsoft.UI.Xaml;
using System.Threading.Tasks;
using WinUIEx;

namespace WinUIDemoApp;

public enum WindowDialogResult
{
    Cancel,
    OK,
}

public partial class WindowDialog : WindowEx
{
    private TaskCompletionSource<WindowDialogResult>? _taskCompletionSource;

    public WindowDialog()
    {
        InitializeComponent();
        IsAlwaysOnTop = true;
        this.CenterOnScreen();
    }

    public new object? Content { get; set; }

    public Task<WindowDialogResult> ShowAsync()
    {
        WidthNumberBox.Value = Width;
        HeightNumberBox.Value = Height;

        _taskCompletionSource = new();

        this.Activate();

        return _taskCompletionSource.Task;
    }

    private void OKButton_Click(object sender, RoutedEventArgs e)
    {
        _taskCompletionSource?.SetResult(WindowDialogResult.OK);
        this.Close();
    }

    private void CancelButton_Click(object sender, RoutedEventArgs e)
    {
        _taskCompletionSource?.SetResult(WindowDialogResult.Cancel);
        this.Close();
    }

    private void WidthNumberBox_ValueChanged(Microsoft.UI.Xaml.Controls.NumberBox sender, Microsoft.UI.Xaml.Controls.NumberBoxValueChangedEventArgs args)
    {
        Width = (float)sender.Value;
    }

    private void HeightNumberBox_ValueChanged(Microsoft.UI.Xaml.Controls.NumberBox sender, Microsoft.UI.Xaml.Controls.NumberBoxValueChangedEventArgs args)
    {
        Height = (float)sender.Value;
    }
}

然后你可以像这样使用它：

WindowDialog dialog = new();
WindowDialogResult result = await dialog.ShowAsync();