Question

I need to draw primitives with graphics object with different transformation matrix. I wonder should I dispose the matrix or graphics will do it for me:

using (var g = Graphics.FromImage(...))
{
    ... some code ...
    var tmp = g.Transform;
    g.TranslateTransform(...);
    ... some code ...
    g.Transform = tmp;
    // should I call tmp.Dispose() here?
    tmp.Dispose();
    ... some code that use g ....
}

http://msdn.microsoft.com/en-us/library/system.drawing.graphics.transform.aspx

Says:

Because the matrix returned and by the Transform property
is a copy of the geometric transform, you should dispose
of the matrix when you no longer need it.

I do not need it after g.Transform = tmp;, should I dispose it?

Answer 1

Quoting MSDN, Graphics.Transform…

Gets or sets a copy of the geometric
world transformation for this
Graphics.

(emphasis mine.)

When you call Transform, you’re making a copy of the Matrix, and you should dispose it yourself. As long as you own them, it’s always a good idea to dispose objects that implement IDisposable, and preferably using the using(...) syntax.