Introduction - If you have any usage issues, please Google them yourself
1 can be set combo box edit box and drop-down list box, font color, font size, (2) can be set to read-only attribute 3. According to the drop-down list item text length widening dropdown width 4. Redraw the drop-down list including borders and items with focus 5 provides a drop-down list item delete function, not read-only and can be removed when the display 6. redraw the edit box border, background, since the painting can expand their own 7. According to the combo box to set the font height Pseudo vertically to achieve the effect, mainly need this