c# - 扩展控件时调整窗口大小

Question

源 self 原来问题的解决方案here

我现在有以下 xaml:

<Window x:Class="MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="300" Width="450" SizeToContent="WidthAndHeight">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="auto" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="auto" />
        </Grid.ColumnDefinitions>
        <TabControl Grid.Column="0" MinWidth="200" Grid.Row="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />       
        <Expander Grid.Column="1" Grid.Row="0" ExpandDirection="Right">
            <StackPanel x:Name="cont">
                <Label>testtesttesttesttest</Label>
                <Label>testtesttesttesttest</Label>
                <Label>testtesttesttesttest</Label>
                <Label>testtesttesttesttest</Label>
                <Label>testtesttesttesttest</Label>
                <Label>testtesttesttesttest</Label>
                <Label>testtesttesttesttest</Label>
                <Label>testtesttesttesttest</Label>
            </StackPanel>
        </Expander>
    </Grid>
</Window>

每次向右扩展扩展器控件时，我都想扩展窗口宽度。当我运行上面引用的 xaml 并在构建后展开扩展器控件时，一切都按预期工作，但只要我手动调整窗口大小，扩展器控件的内容就会扩展到左侧的现有区域。

我怎样才能改变这种行为，以便窗口将其宽度扩展到右侧，并且内容将最终出现在那个新区域中？

Answer 1

这不是 WPF 中内置的东西，因此您必须编写一些自定义代码来处理它。 SizeToContent 一直有效，直到最终用户调整窗口大小，然后窗口大小固定。

你可以使用这样的东西来完成你想要的:

public partial class MainWindow  {
    public MainWindow() {
        InitializeComponent();
    }

    protected override void OnSourceInitialized(EventArgs e) {
        base.OnSourceInitialized(e);

        IntPtr handle = new WindowInteropHelper(this).Handle;
        HwndSource.FromHwnd(handle).AddHook(new HwndSourceHook(this.WindowProc));
    }

    private const int WM_SIZING = 0x0214;
    private const int WM_EXITSIZEMOVE = 0x0232;
    private IntPtr WindowProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled) {
        switch (msg) {
            case WM_SIZING:
                this.firstColumn.ClearValue(ColumnDefinition.MinWidthProperty);
                break;
            case WM_EXITSIZEMOVE:
                this.firstColumn.MinWidth = this.firstColumn.ActualWidth;
                this.SizeToContent = System.Windows.SizeToContent.WidthAndHeight;
                break;
        }

        return IntPtr.Zero;
    }

}

然后您需要将第一个 ColumnDefinition 命名为“firstColumn”，如下所示:

<ColumnDefinition x:Name="firstColumn" Width="*" />

如此有效，它像您一样使用 SizeToContent。如果您调整窗口大小，它会确保第一列的最小大小保持固定大小并重新打开 SizeToContent。

编辑:

注意到您使用了 VB.NET 标记，所以这是 VB.NET 版本:

Public Partial Class MainWindow
    Public Sub New()
        InitializeComponent()
    End Sub

    Protected Overrides Sub OnSourceInitialized(e As EventArgs)
        MyBase.OnSourceInitialized(e)

        Dim handle As IntPtr = New WindowInteropHelper(Me).Handle
        HwndSource.FromHwnd(handle).AddHook(New HwndSourceHook(AddressOf Me.WindowProc))
    End Sub

    Private Const WM_SIZING As Integer = &H214
    Private Const WM_EXITSIZEMOVE As Integer = &H232
    Private Function WindowProc(hwnd As IntPtr, msg As Integer, wParam As IntPtr, lParam As IntPtr, ByRef handled As Boolean) As IntPtr
        Select Case msg
            Case WM_SIZING
                Me.firstColumn.ClearValue(ColumnDefinition.MinWidthProperty)
                Exit Select
            Case WM_EXITSIZEMOVE
                Me.firstColumn.MinWidth = Me.firstColumn.ActualWidth
                Me.SizeToContent = System.Windows.SizeToContent.WidthAndHeight
                Exit Select
        End Select

        Return IntPtr.Zero
    End Function

End Class