C# WinForm 鼠标左键拖动窗体

C# WinForm 鼠标左键拖动窗体

public partial class Form1 : Form
{

Point mouseOff;
bool leftFlag=false;

public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{

}
//第一步
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button==MouseButtons.Left)
{
mouseOff = new Point(-e.X,-e.Y);
leftFlag = true;
}
}
//第二步
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (leftFlag)
{
Point mouseSet = Control.MousePosition;
mouseSet.Offset(mouseOff.X,mouseOff.Y);
this.Location = mouseSet;
}
}
//第三步
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
if (leftFlag)
{
leftFlag = false;
}
}
}