如何正确地将System.Drawing.Point转换为System.Windows.Point
本文关键字：Point System 转换 Windows Drawing 正确地 | 更新日期: 2023-09-27 18:22:01
首先，到目前为止我还没有找到任何答案。这个网站上的文章没有回答我的问题：系统转换器。绘图。点'；到'；System.Windows.Point
在上面的文章中，有人建议这样转换：
//convert
System.Drawing.Point dp = …;
return new System.Windows.Point(dp.X, dp.Y);
但是转换似乎没有得到正确的结果。我从嵌入WPF可视化的WinForm的单击事件中获得了System.Drawing.Point。当我尝试使用上面的转换和VisualTreeHelper.HitTest（）来识别在WPF可视化中单击的控件时，左上角的控件可以正确识别，右下角的控件越多，就越不准确。意味着点转换不是简单的X到X和Y到Y的复制。肯定还涉及其他一些因素。有什么想法吗，我们在转换时需要考虑其他显示因素吗？请运行附件中的程序，点击网格上的不同点，你会发现奇怪的行为。
背景：
我在WinForm中嵌入了一个WPF UI。当单击WinForm上的帮助按钮"？"，然后单击WPF UI中的控件时，WinForm会收到通知，我可以在WinForm中获得正确的System.Drawing.Point。然后我想在WPF中点击相应的位置。我计算了System.Drawing.Point与ElementHost的相对值，ElementHost是连接第一个WPF可视化的最后一个WinForm元素，然后尝试使用上述方法在WPF UI中获取System.Windows.Point，但它没有获得与单击位置对应的正确点。
更多背景：
我们有一些作为UserControls的第三方UI库，这些库无法更改。我们使用WinForm来保存它们。但是，当用户单击WinForm上的"？"按钮（然后鼠标光标变为？），然后单击UserControls中的UI控件时，我们希望侵入UserControls并添加帮助窗口。如果第三方用户界面是纯用WinForm编写的，这就可以很好地工作。
我们所做的是，我们首先通过以下方式在WinForm中获得点击点：System.Drawing.Point pt=此。指向客户端（e.MousePos）；
然后获得了最前面的控制权。Form.GetChildAtPoint（pt）；
然后通过递归地爬上可视化树并记录路径中每个控件的Name属性或Text属性，获得该控件的可视化树路径：控件父级=子级。父母亲
然后，我们使用路径作为字符串来查找预定义的表，以确定标识该控件的关键字。一旦通过关键字识别控件，关键字就可以映射到帮助窗口或其工具提示。
如果一切都是WinForm，则上述过程可以正常工作。
但是，当UserControl包含ElementHost和嵌入的WPF内容时，上述内容就被破坏了。我想只要我能正确地把"System.Drawing.Point"翻译成"System.Windows.Point"，它应该也能工作。
以下代码演示了问题：复制过程：
启动程序。
点击"？"按钮，光标变为"？"。
单击3个按钮中的一个，弹出窗口会给出视觉路径。
对于网格中的两个按钮，第一个按钮提供WPF路径，但第二个按钮没有，因为System.Windows.Point不正确。
//Please add into project the reference to (right click the project and select "Add Reference"): //WindowsBase //WindowsFormsIntegration //PresentationCore //PresentationFramework using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Runtime.InteropServices; using System.Windows.Forms; using System.Windows; using System.Windows.Controls; using System.Windows.Forms.Integration; using System.Windows.Media; namespace WindowsFormsApplication1 {公共分部类Form1:Form{[DllImport（"user32.dll"）]静态外部IntPtr GetFocus（）；
public Form1() { InitializeComponent(); System.Windows.Controls.Button b = new System.Windows.Controls.Button(); b.Content = "WPF_Button"; b.Name = "WPF_Button_name"; Grid.SetColumn(b, 0); Grid.SetRow(b, 0); System.Windows.Controls.Button b2 = new System.Windows.Controls.Button(); b2.Content = "WPF_Button2"; b2.Name = "WPF_Button_name2"; Grid.SetColumn(b2, 2); Grid.SetRow(b2, 2); Grid g = new Grid(); g.Name = "WPF_Grid"; g.Width = 250; g.Height = 100; g.HorizontalAlignment = System.Windows.HorizontalAlignment.Stretch; g.VerticalAlignment = VerticalAlignment.Stretch; g.ShowGridLines = true; // Define the Columns ColumnDefinition colDef1 = new ColumnDefinition(); ColumnDefinition colDef2 = new ColumnDefinition(); ColumnDefinition colDef3 = new ColumnDefinition(); g.ColumnDefinitions.Add(colDef1); g.ColumnDefinitions.Add(colDef2); g.ColumnDefinitions.Add(colDef3); // Define the Rows RowDefinition rowDef1 = new RowDefinition(); RowDefinition rowDef2 = new RowDefinition(); RowDefinition rowDef3 = new RowDefinition(); RowDefinition rowDef4 = new RowDefinition(); g.RowDefinitions.Add(rowDef1); g.RowDefinitions.Add(rowDef2); g.RowDefinitions.Add(rowDef3); g.RowDefinitions.Add(rowDef4); g.Children.Add(b); g.Children.Add(b2); this.elementHost1.Child = g; } // More usefull version of GetChildAtPoint public static System.Windows.Forms.Control FindChildAtPoint(System.Windows.Forms.Control parent, System.Drawing.Point pt, ref string path, out System.Drawing.Point relative_point_inside_child) { //Find a child System.Windows.Forms.Control child = parent.GetChildAtPoint(pt); //If no child, this is the control at the mouse cursor if (child == null) { path += parent.Name; //Offset our current position to be relative to the child to get the point inside the child. relative_point_inside_child = new System.Drawing.Point(pt.X, pt.Y); return parent; } path += parent.Name + "''"; //If a child, offset our current position to be relative to the child System.Drawing.Point childPoint = new System.Drawing.Point(pt.X - child.Location.X, pt.Y - child.Location.Y); //Find child of child control at offset position return FindChildAtPoint(child, childPoint, ref path, out relative_point_inside_child); } private void Form1_HelpRequested(object sender, HelpEventArgs e) { if (System.Windows.Forms.Control.MouseButtons == MouseButtons.None) { //No mouse activity, this function is entered because of F1 key press. //Get the focused Control. If no focused Control then launch overall Help-Window. // IntPtr handle = GetFocus(); if (handle != IntPtr.Zero) { System.Windows.Forms.Control ctl = System.Windows.Forms.Control.FromHandle(handle); //Got the ctl, do whatever } } else { // Help Button ? pressed (After click ?, the mouse cursor changes to ?, // Then user can move the mouse to a UI Control and click it, in this case, // we need find the control that is clicked, the control might not be focused // in such case. // Convert screen coordinates to client coordinates System.Drawing.Point p = this.PointToClient(e.MousePos); System.Drawing.Point pt = this.PointToClient(Cursor.Position); //Look for control user clicked on System.Drawing.Point relative_point_inside_child; string path = ""; System.Windows.Forms.Control ctl = FindChildAtPoint(this, pt, ref path, out relative_point_inside_child); if (ctl is ElementHost) { // This is a WPF view embedded in WinForm, get the root Control UIElement wpf_root = (ctl as ElementHost).Child; if (wpf_root != null) { System.Windows.Point pt_WPF = new System.Windows.Point(relative_point_inside_child.X, relative_point_inside_child.Y); HitTestResult htr = VisualTreeHelper.HitTest(wpf_root, pt_WPF); if (htr != null && htr.VisualHit != null) { //IInputElement elem = System.Windows.Input.Mouse.DirectlyOver; string pathWPF = ""; if (htr.VisualHit is DependencyObject) { FindPathOfControlWPF(htr.VisualHit, ref pathWPF); } if (pathWPF != "") { path = path + pathWPF; } } } } System.Windows.Forms.MessageBox.Show("Clicked on PATH: " + path); e.Handled = true; } } //WPF version of More usefull version of FindPathOfControl public static System.Windows.DependencyObject FindPathOfControlWPF(System.Windows.DependencyObject child, ref string path) { //Find a parent System.Windows.DependencyObject parent = System.Windows.Media.VisualTreeHelper.GetParent(child); if (child is System.Windows.Controls.TextBlock) { path = ":" + (child as System.Windows.Controls.TextBlock).Text + path; } else if (child is System.Windows.Controls.Label) { path = ":" + (child as System.Windows.Controls.Label).Content.ToString() + path; } else if (child is System.Windows.Controls.Primitives.ButtonBase) { path = ":" + (child as System.Windows.Controls.Primitives.ButtonBase).Content.ToString() + path; } if (child is System.Windows.FrameworkElement) { path = (child as System.Windows.FrameworkElement).Name + path; } //If no parent, this is the top control if (parent == null) { return child; } path = "''" + path; //Find parent of child control return FindPathOfControlWPF(parent, ref path); } /// <summary> /// Required designer variable. /// </summary> private System.ComponentModel.IContainer components = null; /// <summary> /// Clean up any resources being used. /// </summary> /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param> protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } #region Windows Form Designer generated code /// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { //this.flowLayoutPanel1 = new System.Windows.Forms.FlowLayoutPanel(); //this.flowLayoutPanel1 = new System.Windows.Forms.Panel(); this.panel1 = new System.Windows.Forms.Panel(); this.button1 = new System.Windows.Forms.Button(); this.panel2 = new System.Windows.Forms.Panel(); this.elementHost1 = new System.Windows.Forms.Integration.ElementHost(); //this.flowLayoutPanel1.SuspendLayout(); this.panel1.SuspendLayout(); this.panel2.SuspendLayout(); this.SuspendLayout(); // // flowLayoutPanel1 // //this.flowLayoutPanel1.Controls.Add(this.panel1); //this.flowLayoutPanel1.Controls.Add(this.panel2); //this.flowLayoutPanel1.Location = new System.Drawing.Point(24, 33); //this.flowLayoutPanel1.Name = "flowLayoutPanel1"; //this.flowLayoutPanel1.Size = new System.Drawing.Size(242, 205); //this.flowLayoutPanel1.TabIndex = 0; //this.flowLayoutPanel1.BackColor = System.Drawing.Color.Blue; // // panel1 // this.panel1.Controls.Add(this.button1); this.panel1.Location = new System.Drawing.Point(3, 3); this.panel1.Name = "panel1"; this.panel1.Size = new System.Drawing.Size(90, 134); this.panel1.TabIndex = 0; this.panel1.BackColor = System.Drawing.Color.Green; this.panel1.BringToFront(); // // button1 // this.button1.Location = new System.Drawing.Point(16, 39); this.button1.Name = "button1"; this.button1.Size = new System.Drawing.Size(60, 35); this.button1.TabIndex = 0; this.button1.Text = "button1"; this.button1.UseVisualStyleBackColor = true; this.button1.BackColor = System.Drawing.Color.Yellow; this.panel1.BringToFront(); // // panel2 // this.panel2.Controls.Add(this.elementHost1); this.panel2.Location = new System.Drawing.Point(99, 3); this.panel2.Name = "panel2"; this.panel2.Size = new System.Drawing.Size(300, 300); this.panel2.TabIndex = 1; this.panel2.BackColor = System.Drawing.Color.Purple; this.panel1.BringToFront(); // // elementHost1 // this.elementHost1.Dock = System.Windows.Forms.DockStyle.Fill; this.elementHost1.Location = new System.Drawing.Point(0, 0); this.elementHost1.Name = "elementHost1"; this.elementHost1.TabIndex = 0; this.elementHost1.Text = "elementHost1Text"; this.elementHost1.Child = null; this.panel1.BringToFront(); // // Form1 // this.HelpButton = true; this.MaximizeBox = false; this.MinimizeBox = false; this.HelpRequested += new System.Windows.Forms.HelpEventHandler(this.Form1_HelpRequested); this.Size = new System.Drawing.Size(600, 600); this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 16F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.ClientSize = new System.Drawing.Size(600, 600); //this.Controls.Add(this.flowLayoutPanel1); this.Controls.Add(this.panel1); this.Controls.Add(this.panel2); this.Name = "Form1"; this.Text = "Form1"; this.BackColor = System.Drawing.Color.Red; //this.flowLayoutPanel1.ResumeLayout(false); this.panel1.ResumeLayout(false); this.panel2.ResumeLayout(false); this.ResumeLayout(false); } #endregion //private System.Windows.Forms.FlowLayoutPanel flowLayoutPanel1; //private System.Windows.Forms.Panel flowLayoutPanel1; private System.Windows.Forms.Panel panel1; private System.Windows.Forms.Button button1; private System.Windows.Forms.Panel panel2; private System.Windows.Forms.Integration.ElementHost elementHost1;}}
最后我找到了解决方案（通过阅读更多关于WPF屏幕坐标的内容和更多测试）。
根本原因是"新System.Windows.Point（dp.X，dp.Y）"无法在不同分辨率、具有多个监视器的计算机等上可靠工作。需要使用变换来获取鼠标相对于当前屏幕的位置，而不是由所有监视器组成的整个查看区域。
另一个主题问题的答案帮助了我：如何在WPF中获取当前鼠标屏幕坐标？
如果更改以下两行我的代码：
System.Windows.Point pt_WPF = new System.Windows.Point(relative_point_inside_child.X, relative_point_inside_child.Y);
HitTestResult htr = VisualTreeHelper.HitTest(wpf_root, pt_WPF);
收件人：
System.Windows.Point pt_WPF = new System.Windows.Point(relative_point_inside_child.X, relative_point_inside_child.Y);
var transform = PresentationSource.FromVisual(wpf_root).CompositionTarget.TransformFromDevice;
pt_WPF = transform.Transform(pt_WPF);
HitTestResult htr = VisualTreeHelper.HitTest(wpf_root, pt_WPF);
然后它工作得很好。