How to move a Windows Form when its FormBorderStyl

问题:

Using C#.
I am trying to move a Form without its title bar.
I found an article about it on: http://www.codeproject.com/KB/cs/csharpmovewindow.aspx

It works as long as I do not set FormBorderStyle as None.

Is there a way to make it work with this property set as None?

回答1:

I know this question is over a year old, but I was searching trying to remember how I've done it in the past. So for anyone else's reference, the quickest and less complex way then the above link is to override the WndProc function.

/*
Constants in Windows API
0x84 = WM_NCHITTEST - Mouse Capture Test
0x1 = HTCLIENT - Application Client Area
0x2 = HTCAPTION - Application Title Bar

This function intercepts all the commands sent to the application. 
It checks to see of the message is a mouse click in the application. 
It passes the action to the base action by default. It reassigns 
the action to the title bar if it occured in the client area
to allow the drag and move behavior.
*/

protected override void WndProc(ref Message m)
{
    switch(m.Msg)
    {
        case 0x84:
            base.WndProc(ref m);
            if ((int)m.Result == 0x1)
                m.Result = (IntPtr)0x2;
            return;
    }

    base.WndProc(ref m);
}

This will allow any form to be moved by clicking and dragging within the client area.

回答2:

Here it is the best way I have found. It is a ".NET way", wihout using WndProc. You just have to handle the MouseDown, MouseMove and MouseUp events of the surfaces you want to be draggable.

private bool dragging = false;
private Point dragCursorPoint;
private Point dragFormPoint;

private void FormMain_MouseDown(object sender, MouseEventArgs e)
{
    dragging = true;
    dragCursorPoint = Cursor.Position;
    dragFormPoint = this.Location;
}

private void FormMain_MouseMove(object sender, MouseEventArgs e)
{
    if (dragging)
    {
        Point dif = Point.Subtract(Cursor.Position, new Size(dragCursorPoint));
        this.Location = Point.Add(dragFormPoint, new Size(dif));
    }
}

private void FormMain_MouseUp(object sender, MouseEventArgs e)
{
    dragging = false;
}

回答3:

I had the same question a while ago and while searching for the answer I found the code below(don't remember the website) and Here is what I do:

    Point mousedownpoint = Point.Empty;

    private void Form_MouseDown(object sender, MouseEventArgs e)
    {
        mousedownpoint = new Point(e.X, e.Y);
    }

    private void Form_MouseMove(object sender, MouseEventArgs e)
    {

        if (mousedownpoint.IsEmpty)
            return;
        Form f = sender as Form;
        f.Location = new Point(f.Location.X + (e.X - mousedownpoint.X), f.Location.Y + (e.Y - mousedownpoint.Y));

    }

    private void Form_MouseUp(object sender, MouseEventArgs e)
    {
        mousedownpoint = Point.Empty;
    }

回答4:

First we will have to use the interop services by using the namespace as

using System.Runtime.InteropServices;

The next thing would be to define the messages that will take care of moving the form. We will have these as class member variables

public const int WM_NCLBUTTONDOWN = 0xA1;
public const int HT_CAPTION = 0x2;
[DllImportAttribute("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
[DllImportAttribute("user32.dll")]
public static extern bool ReleaseCapture();

and finally we will write the code to send the message whenever the user presses the mouse button. The form will be repositioned as per the mouse movement if the user keep the mouse button pressed.

private void Form1_MouseDown(object sender, MouseEventArgs e)
{
    ReleaseCapture();
    SendMessage(this.Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0); 
}

Refer this link Dragable form

Credits to rahul-rajat-singh

回答5:

Point mousedownpoint = Point.Empty;

    private void Form_MouseDown(object sender, MouseEventArgs e)
    {
        mousedownpoint = new Point(e.X, e.Y);
    }

    private void Form_MouseMove(object sender, MouseEventArgs e)
    {

        if (mousedownpoint.IsEmpty)
            return;
        Form f = sender as Form;
        f.Location = new Point(f.Location.X + (e.X - mousedownpoint.X), f.Location.Y + (e.Y - mousedownpoint.Y));

    }

    private void Form_MouseUp(object sender, MouseEventArgs e)
    {
        mousedownpoint = Point.Empty;
    }

    private void panel1_MouseDown(object sender, MouseEventArgs e)
    {
        Form_MouseDown(this, e);
    }

    private void panel1_MouseUp(object sender, MouseEventArgs e)
    {
        Form_MouseUp(this, e);
    }

    private void panel1_MouseMove(object sender, MouseEventArgs e)
    {
        Form_MouseMove(this, e);
    }