为什么 GetWindowRect 在我的 WPF window 中包含标题栏？

Question

我正在尝试使用 GetWindowRect()（和 GetGUIThreadInfo()）获得插入符位置：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Runtime.InteropServices;

namespace WpfApplication1
{
    public class CaretInfo
    {
        public double Width { get; private set; }
        public double Height { get; private set; }
        public double Left { get; private set; }
        public double Top { get; private set; }

        public CaretInfo(double width, double height, double left, double top)
        {
            Width = width;
            Height = height;
            Left = left;
            Top = top;
        }
    }

    public class CaretHelper
    {

        public static CaretInfo GetCaretPosition()
        {
            // Get GUI info containing caret poisition
            var guiInfo = new GUITHREADINFO();
            guiInfo.cbSize = (uint)Marshal.SizeOf(guiInfo);
            GetGUIThreadInfo(0, out guiInfo);

            // Get width/height
            double width = guiInfo.rcCaret.right - guiInfo.rcCaret.left;
            double height = guiInfo.rcCaret.bottom - guiInfo.rcCaret.top;

            // Get left/top relative to screen
            RECT rect;
            GetWindowRect(guiInfo.hwndFocus, out rect);

            double left = guiInfo.rcCaret.left + rect.left + 2;
            double top = guiInfo.rcCaret.top + rect.top + 2;


            int capacity = GetWindowTextLength(guiInfo.hwndFocus) * 2;
            StringBuilder stringBuilder = new StringBuilder(capacity);
            GetWindowText(guiInfo.hwndFocus, stringBuilder, stringBuilder.Capacity);
            Console.WriteLine("Window: " + stringBuilder);
            Console.WriteLine("Caret: " + guiInfo.rcCaret.left + ", " + guiInfo.rcCaret.top);
            Console.WriteLine("Rect : " + rect.left + ", " + rect.top);

            return new CaretInfo(width, height, left, top);
        }

        [DllImport("user32.dll", EntryPoint = "GetGUIThreadInfo")]
        public static extern bool GetGUIThreadInfo(uint tId, out GUITHREADINFO threadInfo);

        [DllImport("user32.dll")]
        public static extern bool ClientToScreen(IntPtr hWnd, out Point position);

        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool GetWindowRect(IntPtr handle, out RECT lpRect);

        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool GetClientRect(IntPtr hWnd, ref Rect rect);

        [StructLayout(LayoutKind.Sequential)]
        public struct GUITHREADINFO
        {
            public uint cbSize;
            public uint flags;
            public IntPtr hwndActive;
            public IntPtr hwndFocus;
            public IntPtr hwndCapture;
            public IntPtr hwndMenuOwner;
            public IntPtr hwndMoveSize;
            public IntPtr hwndCaret;
            public RECT rcCaret;
        };

        [StructLayout(LayoutKind.Sequential)]
        public struct RECT
        {
            public int left;
            public int top;
            public int right;
            public int bottom;
        }

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern int GetWindowTextLe

对于记事本和几乎任何其他地方都可以正确获取坐标：

在我的 WPF（和任何其他 WPF）中 window，但是，GetWindowRect() 决定包含标题栏并将插入符号顶部位置偏移标题栏的高度：

知道为什么吗？

我也尝试使用 DwmGetWindowAttribute()，但它获得的 WPF window 坐标与 GetWindowRect().

相同

编辑：

有了 Brian Reichle 的回答，我已经能够确定一种获取客户区坐标的方法：

[DllImport("user32.dll")]
public static extern bool ClientToScreen(IntPtr hWnd, ref System.Drawing.Point lpPoint);

System.Drawing.Point point = new System.Drawing.Point(0, 0);
ClientToScreen(guiInfo.hwndFocus, ref point)

0,0是guiInfo.hwndFocus指定的window客户区的左上角坐标，总是0,0，因为它是相对于window的客户区。 ClientToScreen() 将坐标转换为相对于屏幕的坐标（必须是 System.Drawing.Point，System.Windows.Point 将不起作用）。

Answer 1

包含标题栏是因为它是 window 的一部分，如果您不想要 non-client 区域，则需要请求客户区域矩形 (GetClientRect) .

记事本造成的混淆可能是因为您使用的是文本框的 window 句柄而不是 window 本身。请记住，WPF 对整个 window 使用单个句柄，而 win32 通常（但不总是）对 window.

中的每个控件使用单独的句柄

在您提到 GetClientRect 'returned' 0,0 的评论中，您是否检查过它返回的是 true（成功）还是 false（失败）？如果返回false，你检查GetLastError()的结果了吗？

为什么 GetWindowRect 在我的 WPF window 中包含标题栏？

Why does GetWindowRect include the title bar in my WPF window?

c#

wpf

pinvoke

caret