c#取指定句柄的内容信息

你可以使用 Windows API 来实现获取指定句柄的内容信息。具体实现步骤如下：

1. 引入 Windows API 相关命名空间：

using System.Runtime.InteropServices;
using System.Text;

2. 定义 Windows API 函数：

[DllImport("user32.dll", SetLastError = true)]
static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);

[DllImport("user32.dll", SetLastError = true)]
static extern int GetWindowTextLength(IntPtr hWnd);

[DllImport("user32.dll", SetLastError = true)]
static extern int GetClassName(IntPtr hWnd, StringBuilder lpClassName, int nMaxCount);

[DllImport("user32.dll", SetLastError = true)]
static extern int SendMessage(IntPtr hWnd, uint Msg, int wParam, StringBuilder lParam);

3. 实现获取指定句柄的内容信息的方法：

public static string GetWindowText(IntPtr hwnd)
{
    int length = GetWindowTextLength(hwnd);
    StringBuilder sb = new StringBuilder(length + 1);
    GetWindowText(hwnd, sb, sb.Capacity);
    return sb.ToString();
}

public static string GetClassName(IntPtr hwnd)
{
    StringBuilder sb = new StringBuilder(256);
    GetClassName(hwnd, sb, sb.Capacity);
    return sb.ToString();
}

public static string GetControlText(IntPtr hwnd)
{
    const uint WM_GETTEXTLENGTH = 0x000E;
    const uint WM_GETTEXT = 0x000D;
    int length = (int)SendMessage(hwnd, WM_GETTEXTLENGTH, 0, null);
    StringBuilder sb = new StringBuilder(length + 1);
    SendMessage(hwnd, WM_GETTEXT, sb.Capacity, sb);
    return sb.ToString();
}

其中，`GetWindowText()` 函数用于获取窗口标题，`GetClassName()` 函数用于获取窗口类名，`GetControlText()` 函数用于获取控件文本内容，`SendMessage()` 函数用于向窗口发送消息。

使用示例：

IntPtr hwnd = new IntPtr(0x12345678); // 替换为你要获取的句柄值
string windowTitle = GetWindowText(hwnd);
string windowClass = GetClassName(hwnd);
string controlText = GetControlText(hwnd);