CODEWITHSUNDEEP
c#winformsvisual-studiovisual-studio-2015
user7007746
user7007746

Reputation:

Visual Studio C# how to move a button's X position by mouse without flicker

So I'm trying to make a slider. I'm using my cursor to move a button's x position.

I have 3 functions, the mouseDown, mouseUp and the mouseMove function. In the mouseUp and mouseDown functions I set a variable to true and false to tell the program that the mouse is clicked or not. In the mouseMove function I tell the program to set the button's x position to the x position of the mouse when the mouse is clicked. This works but has 2 problems.

The first problem is that when I press the button and move it, the button moves along with the mouse's x but it has a space between the mouse and the button. It looks a bit like this: CURSOR.......BUTTON The space between the cursor and button change when I change the resolution of the form.

The second problem is that when I move the button it flickers a bit. It only does this at higher speeds but it is a problem in my case.

My code looks like this:

bool mouseDown = false;

private void volumeGrabBT_MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        mouseDown = true;
    }
}

private void volumeGrabBT_MouseUp(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        mouseDown = false;
    }
}

private void volumeGrabBT_MouseMove(object sender, MouseEventArgs e)
{
    if (mouseDown == true)
    {
        Point volumeBTPoint = new Point();
        volumeBTPoint.X = Cursor.Position.X;
        volumeBTPoint.Y = volumeGrabBT.Location.Y;
        volumeGrabBT.Location = volumeBTPoint;
    }
}

The volumeGrabBT is the button I'm trying to move along with the mouse. The volumeBTPoint is the point of the button I'm trying to set the button's position to.

I hope someone can help me fix these problems. Thanks in advance!

Upvotes: 0

Views: 1826

Answers (2)

Grim Maple
Grim Maple

Reputation: 138

I believe that flickering can be fixed by setting some additional form styles: SetStyle(ControlStyles.AllPaintingInWmPaint |ControlStyles.UserPaint | ControlStyles.DoubleBuffer, true); in form's constructor. It will use double buffering and generally just draws faster.

For the Cursor class, it's relative to the screen, not your form. You can use this.PointToClient() function to get client's space position of cursor, like this: 

Point clientCursor = this.PointToClient(Cursor.Position);

and then use clientCursor to get exact X in your client space.

Upvotes: 0

Alexander Petrov
Alexander Petrov

Reputation: 14241

You have to translate screen coordinates to client coordinates.

Point volumeBTPoint = new Point();
Point point = this.PointToClient(Cursor.Position);
volumeBTPoint.X = point.X;
volumeBTPoint.Y = volumeGrabBT.Location.Y;
volumeGrabBT.Location = volumeBTPoint;

Instead of this you should use button's parent control (Panel, GroupBox, etc).

Upvotes: 0

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