wpf - 确定打开的 WPF 窗口是否在任何监视器上可见

Question

有没有办法确定打开的 WPF 窗口当前是否在任何桌面连接的监视器中可见？可见是指窗口的边界矩形与任何监视器的桌面矩形相交。

我需要此功能来确定是否需要重新定位窗口，因为监视器配置(工作区域边界，监视器计数)在我的应用程序重新启动(保存窗口位置)之间发生了变化。

我想出了下面的代码，它似乎工作，但它有几个问题:

我需要引用 windows 窗体。

我需要桌面的 DPI 设置并将窗口窗体实际像素转换为 WPF 虚拟像素。

我需要一个已经渲染的实际 Visual 实例来执行转换。

您是否知道可以摆脱上述 3 个问题中的部分或全部的解决方案？

using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Forms;
using System.Windows.Media;

internal static class Desktop
{
    private static Size dpiFactor = new Size(1.0, 1.0);
    private static bool isInitialized;

    public static IEnumerable<Rect> WorkingAreas
    {
        get
        {
            return
                Screen.AllScreens.Select(
                    screen =>
                    new Rect(
                        screen.WorkingArea.Left * dpiFactor.Width,
                        screen.WorkingArea.Top * dpiFactor.Height,
                        screen.WorkingArea.Width * dpiFactor.Width,
                        screen.WorkingArea.Height * dpiFactor.Height));
        }
    }

    public static void TryInitialize(Visual visual)
    {
        if (isInitialized)
        {
            return;
        }

        var ps = PresentationSource.FromVisual(visual);
        if (ps == null)
        {
            return;
        }

        var ct = ps.CompositionTarget;
        if (ct == null)
        {
            return;
        }

        var m = ct.TransformToDevice;
        dpiFactor = new Size(m.M11, m.M22);
        isInitialized = true;
    }
}

(初始化的) Desktop 的用法类(class):

    private bool IsLocationValid(Rect windowRectangle)
    {
        foreach (var workingArea in Desktop.WorkingAreas)
        {
            var intersection = Rect.Intersect(windowRectangle, workingArea);
            var minVisible = new Size(10.0, 10.0);
            if (intersection.Width >= minVisible.Width && 
                intersection.Height >= minVisible.Height)
            {
                return true;
            }
        }

        return false;
    }

更新

使用虚拟屏幕 ( SystemParameters.VirtualScreen* ) 不起作用，因为当使用多个显示器时，“桌面”不是一个简单的矩形。它可能是一个多边形。虚拟屏幕会有盲点，因为

连接的屏幕可以有不同的分辨率

您可以配置每个屏幕的位置。

Answer 1

我在启动时使用在我的 WPF 项目中剪断的这段代码；它是用 vb.net 编写的:

If My.Settings.RememberWindowPositionAndSize Then
    If My.Settings.winMainWinState > 2 Then My.Settings.winMainWinState = WindowState.Normal
    If My.Settings.winMainWinState = WindowState.Minimized Then My.Settings.winMainWinState = WindowState.Normal
    Me.WindowState = My.Settings.winMainWinState
    If My.Settings.winMainWinState = WindowState.Normal Then
        Dim winBounds As New System.Drawing.Rectangle(CInt(My.Settings.winMainPosX), CInt(My.Settings.winMainPosY),
                                                      CInt(My.Settings.winMainSizeB), CInt(My.Settings.winMainSizeH))
        For Each scr As System.Windows.Forms.Screen In System.Windows.Forms.Screen.AllScreens
            If winBounds.IntersectsWith(scr.Bounds) Then
                Me.Width = My.Settings.winMainSizeB
                Me.Height = My.Settings.winMainSizeH
                Me.Top = My.Settings.winMainPosY
                Me.Left = My.Settings.winMainPosX
                Exit For
            End If
        Next
    End If
End If

这是 C# 中相同的(转换后的)代码

if (My.Settings.RememberWindowPositionAndSize) {
    if (My.Settings.winMainWinState > 2)
        My.Settings.winMainWinState = WindowState.Normal;
    if (My.Settings.winMainWinState == WindowState.Minimized)
        My.Settings.winMainWinState = WindowState.Normal;
    this.WindowState = My.Settings.winMainWinState;

    if (My.Settings.winMainWinState == WindowState.Normal) {
        System.Drawing.Rectangle winBounds = new System.Drawing.Rectangle(Convert.ToInt32(My.Settings.winMainPosX), Convert.ToInt32(My.Settings.winMainPosY), Convert.ToInt32(My.Settings.winMainSizeB), Convert.ToInt32(My.Settings.winMainSizeH));

        foreach (System.Windows.Forms.Screen scr in System.Windows.Forms.Screen.AllScreens) {
            if (winBounds.IntersectsWith(scr.Bounds)) {
                this.Width = My.Settings.winMainSizeB;
                this.Height = My.Settings.winMainSizeH;
                this.Top = My.Settings.winMainPosY;
                this.Left = My.Settings.winMainPosX;
                break;
            }
        }
    }
}