which is the easiest way to change Font size with C#.
with java it can all be done easily by calling Font constructor with necessary arguments.
JLabel lab = new JLabel("Font Bold at 24");
lab.setFont(new Font("Serif", Font.BOLD, 24));

解决方案

Maybe something like this:
yourformName.YourLabel.Font = new Font("Arial", 24,FontStyle.Bold);
Or if you are in the same class as the form then simply do this:
YourLabel.Font = new Font("Arial", 24,FontStyle.Bold);
The constructor takes diffrent parameters (so pick your poison). Like this:
Font(Font, FontStyle)
Font(FontFamily, Single)
Font(String, Single)
Font(FontFamily, Single, FontStyle)
Font(FontFamily, Single, GraphicsUnit)
Font(String, Single, FontStyle)
Font(String, Single, GraphicsUnit)
Font(FontFamily, Single, FontStyle, GraphicsUnit)
Font(String, Single, FontStyle, GraphicsUnit)
Font(FontFamily, Single, FontStyle, GraphicsUnit, Byte)
Font(String, Single, FontStyle, GraphicsUnit, Byte)
Font(FontFamily, Single, FontStyle, GraphicsUnit, Byte, Boolean)
Font(String, Single, FontStyle, GraphicsUnit, Byte, Boolean)
Reference here