The operation logic of this test procedure is that after each input line, within the program will add a line and a space,


1. Above all, during initialization, the richtextbox fonts have been set to Microsoft Yahai, 12,
2. Each new generation the row has a font width, contains two cursor position, one red, one green,
3. If the cursor to input directly from the red font, font display is normal; If delete to red from green font on the cursor, input the font is normal; If the from red font back to delete the blank space, the input font into a smaller font, 8

Question:
I use a RichtextBox. The Font=new Font (" Microsoft Yahei ", 12); The methods to set and what is wrong with this way? This unusual 8 font Settings from where come of? If set to ensure implementation in the default font when input? Thank you,