将表单作为参数传递给图形C＃

Question

I'm working with graphics in windows forms. I need to pass the form itself (named form1 ) which is calling the graphics class Grafika() so that while drawing I can use form1.CreateGraphics() to draw on that specific form.

The constructor for the graphics class Grafika looks like this:

public Grafika(ref Form predan)
{
    grafika=predan.CreateGraphics();
    //drawing on the form
}

How to pass a form into the constructor of Grafika so that I can use it?

Answer 1

The same way you have posted, have your constructor accepts a parameter of that specific form. But you don't need the ref keyword since Form is of reference type itself. Here Form1 is a specific Form object considering you have a form of that name

public Grafika(Form1 predan)
{
    grafika=predan.CreateGraphics();
    //drawing on the form
}

Answer 2

If you need to pass it along don't use ref . If you remove the ref you can pass it like so:

//From Form1
Grafika g = new Grafika(this);
//If called from the From, 'this' will be the form itself

Also your constructor should look like this:

public Grafika(Form1 predan)//Notice Form1 instead of just Form
{
    grafika=predan.CreateGraphics();
    //drawing on the form
}