using System;
using System.Diagnostics;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;
using mshtml;
using SHDocVw;

namespace CapIe
{
    public partial class Form1 : Form
    {
        private fields#region private fields

        窗口相关#region 窗口相关

        [DllImport("user32.dll")]
        private static extern int GetClassName(
            IntPtr hWnd,
            StringBuilder lpString,
            int nMaxCount
            );

        [DllImport("user32.dll")]
        private static extern IntPtr GetForegroundWindow();

        #endregion

        拖动无标题窗口相关#region 拖动无标题窗口相关

        public const int HTCAPTION = 0x0002;
        public const int SC_MOVE = 0xF010;
        public const int WM_SYSCOMMAND = 0x0112;

        [DllImport("user32.dll")]
        public static extern bool ReleaseCapture();

        [DllImport("user32.dll")]
        public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);

        #endregion

        private readonly Timer _timer = new Timer();
        private IHTMLDocument2 _doc;

        #endregion

        Form 相关#region Form 相关

        public Form1()
        {
            InitializeComponent();
            TopMost = true;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            _timer.Enabled = true;
            _timer.Tick += _timer_Tick;
            Location = new Point(Screen.PrimaryScreen.WorkingArea.Width - base.Width,
                                 Screen.PrimaryScreen.WorkingArea.Height - Height); //让窗体初始化在屏幕的右下角
        }

        #endregion

        网页捕捉相关#region 网页捕捉相关

        //监控当前窗口是否为IE
        private void _timer_Tick(object sender, EventArgs e)
        {
            try
            {
                IntPtr formHandle = GetForegroundWindow();
                if (formHandle == Handle) return;
                StringBuilder className = new StringBuilder(256);
                GetClassName(formHandle, className, className.Capacity);
                if (className.ToString() != "IEFrame")
                {
                    toolStripButton1.Enabled = false;
                    toolStripButton2.Enabled = false;
                    return;
                }
                else
                {
                    toolStripButton1.Enabled = true;
                    toolStripButton2.Enabled = true;
                }


                ShellWindows shell = new ShellWindowsClass();
                int ihandle = formHandle.ToInt32();
                foreach (InternetExplorer ie in shell)
                {
                    int iehandle;
                    try
                    {
                        iehandle = ie.HWND;
                    }
                    catch
                    {
                        continue;
                    }
                    if (ihandle != iehandle) continue;
                    try
                    {
                        _doc = ie.Document as IHTMLDocument2;
                    }
                    catch
                    {
                        continue;
                    }
                }
            }
            catch (Exception ex)
            {
                Trace.TraceError(ex.Message);
                Debugger.Break();
            }
        }

        //捕获全部网页
        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            if (_doc == null) return;
            ShowWeb showWeb = new ShowWeb(_doc.body.innerHTML);
            showWeb.ShowDialog(this);
        }


        //捕获选取的网页
        private void toolStripButton2_Click(object sender, EventArgs e)
        {
            if (_doc == null) return;
            IHTMLTxtRange range = _doc.selection.createRange() as IHTMLTxtRange;
            if (range == null) return;
            ShowWeb showWeb = new ShowWeb(range.htmlText);
            showWeb.ShowDialog(this);
        }

        #endregion

        窗体拖动相关#region 窗体拖动相关

        private void panel1_MouseDown(object sender, MouseEventArgs e)
        {
            ReleaseCapture();
            SendMessage(Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
        }

        private void panel1_MouseHover(object sender, EventArgs e)
        {
            Cursor = Cursors.SizeAll;
        }

        private void panel1_MouseLeave(object sender, EventArgs e)
        {
            Cursor = Cursors.Default;
        }

        #endregion

        下拉菜单处理#region 下拉菜单处理

        private void 退出ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

        #endregion

        private void toolStrip1_MouseHover(object sender, EventArgs e)
        {
            Focus(); //解决按钮要点击两次的bug
        }
    }
}

[DllImport("user32")]
private static extern IntPtr WindowFromPoint(
Point Point  //坐标
);
[DllImport("User32.dll")]
public static extern IntPtr GetParent(IntPtr hWnd);

int x = Cursor.Position.X;
int y = Cursor.Position.Y;
Point p = new Point(x, y);
IntPtr formHandle = WindowFromPoint(p);