C#

FormX objX = new FormX();

// cast down
Form obj = objX;

// now you can call the foo method
foo(ref obj);

foo(System.Windows.Forms.Form obj)
{
    // obj is passed as a reference by default since it's a reference type
}

Member 2463256 wrote:

However, since FormX is a reference type, your foo method doesn't even need the ref parameter keyword. c# passes it as a reference by default.

foo(ref Form obj)
{
  // The caller's variable is changed to a new
  // Form instance.
  obj = new Form();
}

foo(Form obj)
{
  // Our LOCAL variable 'obj' is set to a new form, but
  // the calling function will see no change.
  obj = new Form();
}

Ian Shlasko wrote:

except that "out" only works in one direction, while "ref" both provides a value and allows it to be changed.

// Notice myForm was not initialized.
Form myForm;
SomeMethod(out myForm);
// This will work.
myForm.ShowDialog();

// Notice myForm was not initialized.
Form myForm;
SomeMethod(ref myForm);
// This will NOT work (compile time error), because myForm may not have been initialized.
myForm.ShowDialog();

C:\Program Files (x86)\Combined Community Codec Pack\MPC\mpc-hc.exe

C:\"Program Files (x86)"\"Combined Community Codec Pack"\MPC\mpc-hc.exe

Luc Pattyn wrote:

it is a real pain, but in complex situations Windows seems to require each folder level with spaces to be put in its own pair of double quotes, hence:

// Insert quotes when needed by file names that contain spaces.
public static string QuoteSpaces(string f) {
	env.log(env.TRACE,"quoted in: "+f);
	if (f.IndexOf(' ')>=0) {
		string[] fa=LP_String.Split(f,'\\');
		StringBuilder sb=new StringBuilder(100);
		for (int i=0; i<fa.Length; i++) {
			if (i!=0) sb.Append('\\');
			string fi=fa[i];
			if (fi.IndexOf(' ')>=0) {
				sb.Append('\\');
				sb.Append('"');
				sb.Append(fi);
				sb.Append('"');
			} else {
				sb.Append(fi);
			}
		}
		f=sb.ToString();
	}
	env.log(env.TRACE,"quoted out: "+f);
	return f;
}