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Nacho Zve De La Torre
Asked: 2020-06-05 18:02:54 +0800 CST 2020-06-05 18:02:54 +0800 CST

How to create dynamic buttons that can be moved at runtime? Windows Forms

  • 772

I'm trying to make a table system for a restaurant, but things are getting difficult. What I want to do is a button that when clicked creates new buttons (at runtime/dynamic - or new restaurant tables) and then be able to move those same buttons (tables) and position them inside the Main Form.

My main form has these 4 variables:

 int posMouseFormX, posMouseFormY, posMouseBotonX, posMouseBotonY, 
 posActBotonX, posActBotonY

I have this code that creates the button for me when I start the form:

     private void crearNuevaMesa()
    {
        for (int i = 0; i < 10; i++)
        {
            Button btn = new Button();
            btn.Name = "btn" + i;
            btn.Height = 40;
            btn.Width = 300;
            btn.BackColor = Color.Red;

            btn.Location = new Point(200, 200);
            btn.Text = "SOY UNA NUEVA MESA";
            btn.Font = new Font("Georgia", 16);

            btn.MouseMove += new MouseEventHandler(btn_MouseMove);

            Controls.Add(btn);
        }
    }

And then I invoke this other method to set the coordinates:

      private void btn_MouseMove(object sender, EventArgs e)
    {
        posMouseFormX = posActBotonX + e.Location.X;
        posMouseFormY = posActBotonY + e.Location.Y;
        if (botonPresionado == true)
        {
            moverBoton();
        }
    }

But it breaks me in the e.Location.X of the btn_MouseMove method and I don't know why !!!! Someone help me ??

c#

2 Answers

  1. Best Answer

    Gerardo is right, the event handler signature MouseMoveexpects one MouseEventArgsthat does have the Location. But you have some other problem.

    e.Locationin the MouseMovebutton event it will return the mouse position relative to the button . This obviously isn't going to allow you to move it as you expect.

    I leave you a simple solution to move a button when you click on it and while you do not release the mouse button. First, I add a variable to store the button that was clicked on the form:

    private string botonArrastrando="";

    Then we add the necessary events in the creation of the button:

    private void crearNuevaMesa()
{
    for (int i = 0; i < 10; i++)
    {
        Button btn = new Button();
        btn.Name = "btn" + i;
        btn.Height = 40;
        btn.Width = 300;
        btn.BackColor = Color.Red;

        btn.Location = new Point(200, 200);
        btn.Text = "SOY UNA NUEVA MESA";
        btn.Font = new Font("Georgia", 16);

        btn.MouseMove += new MouseEventHandler(btn_MouseMove);
        btn.MouseDown += new MouseEventHandler(btn_MouseDown);
        btn.MouseUp += new MouseEventHandler(btn_MouseUp);

        Controls.Add(btn);
    }
}

    As you can see, I add the events MouseDownand MouseUp. Now these would be the handlers:

    private void btn_MouseMove(object sender, MouseEventArgs e)
{
    Point l = this.PointToClient(Cursor.Position);
    if (((Button)sender).Name==botonArrastrando)
    {
        ((Button)sender).Location = l;
    }
}

private void btn_MouseDown(object sender, MouseEventArgs e)
{
    botonArrastrando = ((Button)sender).Name;
}

private void btn_MouseUp(object sender, MouseEventArgs e)
{
    botonArrastrando = "";
}

    As you can see, when a button is pressed, its name is stored in the variable that controls which button is moving, and when it is released, that variable is deleted. Then, MouseMovethe position of the cursor is taken using PointToClientto obtain said position with respect to the form, and if the button is the one we are moving, we put its position in the location of the cursor.

    • 5

  2. very good,

    I think you have the problem in the implementation of the btn_MouseMove method since you define the e parameter as EventArgs and you should declare it as MouseEventArgs , since otherwise it doesn't recognize the Location property .

    I leave you the corrected method:

    private void btn_MouseMove(object sender, MouseEventArgs e)
    {
        posMouseFormX = posActBotonX + e.Location.X;
        posMouseFormY = posActBotonY + e.Location.Y;
        if (botonPresionado == true)
        {
            moverBoton();
        }
    }

    Greetings and I hope it helps you.

    • 3