DrawString（）问题和自定义控件的大小调整

Question

I am working on some custom controls and I am looking for some feedback. One of the controls looks similar to a standard TextBox at design time, and when it is dragged and dropped onto a design surface the name of the control is written in the text area. This all works fine, but I feel that there is an easier way to accomplish what I have done. I have the following code:

public override void Draw(Graphics graphics)
{
        graphics.FillRectangle(new SolidBrush(BackColor), ClientRectangle);
        graphics.DrawString(Text, Font, new SolidBrush(ForeColor), TextRectangle, format);
        DrawControl(graphics);
}

protected void DrawControl(Graphics graphics)
{
        CotrolPaint.DrawBorder3D(graphics, ClientRectangle, Border3DStyle.Etched);
}

protected Rectangle TextRectangle
{
        get
        {

            return new Rectangle(ClientRectangle.Left + 2,
                                        ClientRectangle.Top + 2,
                                        ClientRectangle.Width - 5,
                                        ClientRectangle.Height - 5);
        }
}

Looking over the code now, TextRectangle should probably be a readonly constant, but I digress. The code is fairly straightforward, the bit I am hung up on is my TextRectangle property. The reason I am using this is instead of ClientRectangle is because the text that is written inside the rectangle gets cut off by several pixels. Thus I have a smaller rectangle that is offset a bit. This works, but it feels like a "hack". I have to believe that there is a better way to do this than what I have demonstrated here.

The next issue I have is difficult to explain, so I have provided a couple images. If I drag my custom control from the toolbox onto the design surface, it looks similar to this:

However if I manually resize the control, the selection rectangle retains its previous size:

I am somewhat at a loss on how to fix this. Any help on either question would be greatly appreciated!

Answer 1

What you do for the first issue is not really some kind of hack, in fact many default controls are drawn with some hard-coded padding (commonly used are 1 and 2 ...). Normally the maximum Rectangle for the text bounds is ClientRectangle , if you want some padding, of course you can just adjust it (like as you did).

For the second issue, it's because you don't have any code to invalidate the control after its size is changed, even you have to invalidate when the text , font and forecolor are changed. Try adding the following code to your code and it should work:

protected override void OnSizeChanged(EventArgs e){
  base.OnSizeChanged(e);
  Invalidate();
}
protected override void OnTextChanged(EventArgs e){
  base.OnTextChanged(e);
  Invalidate();
}
protected override void OnFontChanged(EventArgs e){
  base.OnFontChanged(e);
  Invalidate();
}
protected override void OnForeColorChanged(EventArgs e){
  base.OnForeColorChanged(e);
  Invalidate();
}