ASP.net生成文字图片

string_FontName=Request["fontname"].ToString();
int_FontSize=Convert.ToInt16(Request["fontsize"]);
string_ShowName=Request["str"].ToString();

BitmapobjBitmap=null;
Graphicsg=null;

FontstringFont=newFont(_FontName,_FontSize,FontStyle.Bold);
StringFormatstringFormat=newStringFormat();
stringFormat.FormatFlags=StringFormatFlags.NoWrap;

try
{
objBitmap=newBitmap(1,1);
g=Graphics.FromImage(objBitmap);
SizeFstringSize=g.MeasureString(_ShowName,stringFont);
intnWidth=(int)stringSize.Width;
intnHeight=(int)stringSize.Height;
g.Dispose();
objBitmap.Dispose();

objBitmap=newBitmap(nWidth,nHeight);
g=Graphics.FromImage(objBitmap);
g.FillRectangle(newSolidBrush(Color.Yellow),newRectangle(0,0,nWidth,nHeight));
g.TextRenderingHint=TextRenderingHint.AntiAlias;
g.DrawString(_ShowName,stringFont,newSolidBrush(Color.Black),newPointF(0,0),stringFormat);　
objBitmap.Save(Response.OutputStream,ImageFormat.Gif);
}
catch(Exceptionee)
{
Response.Write(ee.ToString());
}
finally
{
if(null!=g)g.Dispose();
if(null!=objBitmap)objBitmap.Dispose();
Response.End();
}