winfrom窗体自带的边框不好看，可以将FormBorderStyle设置为None去除边框，但这样窗体无法拖动
下面记录无边框窗体拖动的几种方法[参考其他博主的]：
1.Form触发MouseDown事件时，记录鼠标坐标：
rawPoint = e.Location;
MouseMove时根据鼠标坐标的移动偏移量，设置窗体位置同步变化：
void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button != System.Windows.Forms.MouseButtons.Left)
return;
int x = e.X - rawPoint.X;
int y = e.Y - rawPoint.Y;
this.Location = new Point(this.Location.X + x, this.Location.Y + y);
}
2.Form上方放置控件(如Label)来模拟边框，通过控件的MouseDown和MouseMove事件来实现,同方法1；
3.调用win32 api，Form的MoveDown触发时，向系统发送鼠标点击窗体非客户区的消息（模拟点击窗体边框）：
[DllImport("user32.dll")]
public static extern bool ReleaseCapture();
[DllImport("user32.dll")]
public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);
private const int LeftButtonDown = 0xA1;
private const int HTCaption = 0x02;
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
ReleaseCapture();
SendMessage((IntPtr)this.Handle, LeftButtonDown, HTCaption, 0);
}
4.重写WndProc函数，拦截鼠标左击窗体的消息，改为左击窗体的非客户区：
protected override void WndProc(ref Message m)
{
switch (m.Msg)
{
case 0x0201:
{
m.Msg = 0xA1;
m.WParam = new IntPtr(2);
m.LParam = new IntPtr(0);
}
break;
}
base.WndProc(ref m);
}
以上方式均可实现窗体拖动。