C#中实现拖动无边框Form窗体和窗体的起始位置

拖动无边框窗体Form至桌面任何位置

首先建一个Windows应用程序

将Form1的 FormBorderStyle属性设置为Noe

主要是在Form1窗体触发三个事件：Form4_MouseDown，Form4_MouseMove，Form4_MouseUp

代码如下：

public partial class Form1 : Form
    {
        Point mouseOff;                          //鼠标移动位置变量
        bool leftFlag;                               //标签是否为左键

        public Form1()
        {
            InitializeComponent();

        }

//用代码设置窗体的起始位置

private void Form_Load(object sender, System.EventArgs e)
{
     this.Left=(int)((Screen.PrimaryScreen.Bounds.Width-this.Width)/2);
     this.Top=(int)((Screen.PrimaryScreen.Bounds.Height-this.Height)/2);
}

       private void Form1_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                mouseOff = new Point(-e.X, -e.Y); //得到变量的值
                leftFlag = true;                              //点击左键按下时标注为true;
            }
        }

        private void Form1_MouseMove(object sender, MouseEventArgs e)
        {
            if (leftFlag)
            {
                Point mouseSet = Control.MousePosition;
                mouseSet.Offset(mouseOff.X, mouseOff.Y); //设置移动后的位置
                Location = mouseSet;
            }
        }

        private void Form1_MouseUp(object sender, MouseEventArgs e)
        {
            if (leftFlag)
            {
                leftFlag = false;//释放鼠标后标注为false;
            }
        }

    }