问如何使用DrawString绘制只包含空格的字符串下划线？

EN

Bitmap bitmap = new Bitmap(400, 200);
Graphics graphics = Graphics.FromImage(bitmap);
Brush brush = new SolidBrush(Color.White);
graphics.FillRectangle(brush, 0, 0, 400, 200);
System.Drawing.Font font = new System.Drawing.Font("Arial", 12, FontStyle.Underline);
brush = new SolidBrush(Color.Black);
StringFormat stringformat = new StringFormat(StringFormat.GenericTypographic);
stringformat.FormatFlags |= StringFormatFlags.MeasureTrailingSpaces;
string text = "Hello";
SizeF sizeF = m_graphics.MeasureString(text, font, new PointF(0, 0), stringformat);
graphics.DrawString(text, font, brush, new RectangleF(0, 0, sizeF.Width, sizeF.Height), stringformat);
text = "     ";
float width = sizeF.Width;
sizeF = m_graphics.MeasureString(text, font, new PointF(0, 0), stringformat);
graphics.DrawString(text, font, brush, new RectangleF(width, 0, sizeF.Width, sizeF.Height), stringformat);
text = "World";
width += sizeF.Width;
sizeF = m_graphics.MeasureString(text, font, new PointF(0, 0), stringformat);
graphics.DrawString(text, font, brush, new RectangleF(width, 0, sizeF.Width, sizeF.Height), stringformat);