WinForm无边框拉伸大小

WinForm实现无边框，边界可拉伸窗体大小

using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        private const int WM_NCHITTEST = 0x0084; //鼠标在窗体客户区（除标题栏和边框以外的部分）时发送的信息
        const int HTLEFT = 10;  //左变
        const int HTRIGHT = 11;  //右边
        const int HTTOP = 12;
        const int HTTOPLEFT = 13;  //左上
        const int HTTOPRIGHT = 14; //右上
        const int HTBOTTOM = 15;  //下
        const int HTBOTTOMLEFT = 0x10;  //左下
        const int HTBOTTOMRIGHT = 17;  //右下


        [DllImport（“user32.dll“ CharSet = CharSet.Auto）]
        public static extern int SendMessage（IntPtr hWnd int msg int wParam int lParam）;
        [DllImport（“User32.dll“ CharSet = CharSet

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     目录           0  2014-02-18 11:30  WindowsFormsApplication2\
     目录           0  2014-02-18 10:47  WindowsFormsApplication2\bin\
     目录           0  2014-02-18 11:26  WindowsFormsApplication2\bin\Debug\
     文件       13824  2014-02-18 12:19  WindowsFormsApplication2\bin\Debug\WindowsFormsApplication2.exe
     文件       38400  2014-02-18 12:19  WindowsFormsApplication2\bin\Debug\WindowsFormsApplication2.pdb
     文件       11600  2014-02-18 13:20  WindowsFormsApplication2\bin\Debug\WindowsFormsApplication2.vshost.exe
     文件         490  2009-08-31 00:40  WindowsFormsApplication2\bin\Debug\WindowsFormsApplication2.vshost.exe.manifest
     目录           0  2014-02-18 10:47  WindowsFormsApplication2\bin\Release\
     文件        3696  2014-02-18 12:17  WindowsFormsApplication2\Form1.cs
     文件        6357  2014-02-18 11:32  WindowsFormsApplication2\Form1.Designer.cs
     文件        5817  2014-02-18 11:32  WindowsFormsApplication2\Form1.resx
     文件        3413  2014-02-18 11:30  WindowsFormsApplication2\loading.gif
     文件        3884  2014-02-18 11:34  WindowsFormsApplication2\MyOpaquelayer.cs
     目录           0  2014-02-18 09:58  WindowsFormsApplication2\obj\
     目录           0  2014-02-18 09:58  WindowsFormsApplication2\obj\x86\
     目录           0  2014-02-18 12:19  WindowsFormsApplication2\obj\x86\Debug\
     文件        4440  2014-02-18 10:38  WindowsFormsApplication2\obj\x86\Debug\DesignTimeResolveAssemblyReferences.cache
     文件        6511  2014-02-18 12:19  WindowsFormsApplication2\obj\x86\Debug\DesignTimeResolveAssemblyReferencesInput.cache
     文件         480  2014-02-18 11:35  WindowsFormsApplication2\obj\x86\Debug\GenerateResource.read.1.tlog
     文件        1720  2014-02-18 11:35  WindowsFormsApplication2\obj\x86\Debug\GenerateResource.write.1.tlog
     文件        7897  2014-02-18 10:40  WindowsFormsApplication2\obj\x86\Debug\ResolveAssemblyReference.cache
     目录           0  2014-02-18 09:58  WindowsFormsApplication2\obj\x86\Debug\TempPE\
     文件        1321  2014-02-18 13:20  WindowsFormsApplication2\obj\x86\Debug\WindowsFormsApplication2.csproj.FileListAbsolute.txt
     文件       13824  2014-02-18 12:19  WindowsFormsApplication2\obj\x86\Debug\WindowsFormsApplication2.exe
     文件         180  2014-02-18 11:35  WindowsFormsApplication2\obj\x86\Debug\WindowsFormsApplication2.Form1.resources
     文件       38400  2014-02-18 12:19  WindowsFormsApplication2\obj\x86\Debug\WindowsFormsApplication2.pdb
     文件         180  2014-02-18 11:30  WindowsFormsApplication2\obj\x86\Debug\WindowsFormsApplication2.Properties.Resources.resources
     文件        1957  2014-02-18 11:36  WindowsFormsApplication2\OpaqueCommand.cs
     文件         505  2014-02-18 09:58  WindowsFormsApplication2\Program.cs
     目录           0  2014-02-18 09:58  WindowsFormsApplication2\Properties\
     文件        1380  2014-02-18 09:58  WindowsFormsApplication2\Properties\AssemblyInfo.cs
............此处省略5个文件信息