微信电脑端截图 dll 库实现微信截图功能详解

using System;

using System.Collections.Generic;

using System.Runtime.InteropServices;

using System.Windows.Forms;

namespace screenT

{

  public partial class ScreenForm : Form

  {

    public ScreenForm()

    {

      InitializeComponent();

    }

    private void ScreenCapture()

    {

      DLL.PrScrn();

    }

    protected override void WndProc(ref Message m)

    {

      base.WndProc(ref m);

      Hotkey.ProcessHotKey(m);

    }

    private void button1_Click(object sender, EventArgs e)

    {

      DLL.PrScrn();

    }

    private void Form1_Load(object sender, EventArgs e)

    {

      //注册热键(窗体句柄,热键ID,辅助键,实键) 

      try

      {

        Hotkey.Regist(Handle, HotkeyModifiers.MOD_ALT, Keys.F1, ScreenCapture);

      }

      catch (Exception te)

      {

        MessageBox.Show("Alt + A 热键被占用");

      }

    }

    private void Form1_FormClosed(object sender, FormClosedEventArgs e)

    {

      //注消热键(句柄,热键ID) 

      Hotkey.UnRegist(Handle, ScreenCapture);

    }

  }

  public class DLL

  {

    [DllImport("PrScrn.dll", EntryPoint = "PrScrn")]

    public static extern int PrScrn(); //与dll中一致 

  }

  public static class Hotkey

  {

    #region 系统api

    [DllImport("user32.dll")]

    [return: MarshalAs(UnmanagedType.Bool)]

    private static extern bool RegisterHotKey(IntPtr hWnd, int id, HotkeyModifiers fsModifiers, Keys vk);

    [DllImport("user32.dll")]

    private static extern bool UnregisterHotKey(IntPtr hWnd, int id);

    #endregion

    public delegate void HotKeyCallBackHanlder();

    private const int WM_HOTKEY = 0x312;

    private static int keyid = 10;

    private static readonly Dictionary<int, HotKeyCallBackHanlder> keymap =

      new Dictionary<int, HotKeyCallBackHanlder>();

    /// <summary>

    ///   注册快捷键

    /// </summary>

    /// <param name="hWnd">持有快捷键窗口的句柄</param>

    /// <param name="fsModifiers">组合键</param>

    /// <param name="vk">快捷键的虚拟键码</param>

    /// <param name="callBack">回调函数</param>

    public static void Regist(IntPtr hWnd, HotkeyModifiers fsModifiers, Keys vk, HotKeyCallBackHanlder callBack)

    {

      int id = keyid++;

      if (!RegisterHotKey(hWnd, id, fsModifiers, vk))

        throw new Exception("regist hotkey fail.");

      keymap[id] = callBack;

    }

    /// <summary>

    ///   注销快捷键

    /// </summary>

    /// <param name="hWnd">持有快捷键窗口的句柄</param>

    /// <param name="callBack">回调函数</param>

    public static void UnRegist(IntPtr hWnd, HotKeyCallBackHanlder callBack)

    {

      foreach (var var in keymap)

      {

        if (var.Value == callBack)

          UnregisterHotKey(hWnd, var.Key);

      }

    }

    /// <summary>

    ///   快捷键消息处理

    /// </summary>

    public static void ProcessHotKey(Message m)

    {

      if (m.Msg == WM_HOTKEY)

      {

        int id = m.WParam.ToInt32();

        HotKeyCallBackHanlder callback;

        if (keymap.TryGetValue(id, out callback))

        {

          callback();

        }

      }

    }

  }

  public enum HotkeyModifiers

  {

    MOD_ALT = 0x1,

    MOD_CONTROL = 0x2,

    MOD_SHIFT = 0x4,

    MOD_WIN = 0x8

  }

}