求高手帮忙看下下面的方法是干嘛的，顺便每一行都标上注释，50分辛苦费双手奉上
public void CreateImage(string str_ValidateCode)
{
int bmpWidth = str_ValidateCode.Length * 9;
int bmpHight = 0x12;
Random newRandom = new Random();
Bitmap theBitmap = new Bitmap(bmpWidth, bmpHight);
Graphics theGraphics = Graphics.FromImage(theBitmap);
theGraphics.Clear(Color.White);
Font theFont = new Font("Verdana", 9f);
for (int int_index = 0; int_index < str_ValidateCode.Length; int_index++)
{
string str_char = str_ValidateCode.Substring(int_index, 1);
Brush newBrush = new SolidBrush(this.GetRandomColor());
Point thePos = new Point(int_index * 8, 2);
theGraphics.DrawString(str_char, theFont, newBrush, (PointF) thePos);
}
MemoryStream ms = new MemoryStream();
theBitmap.Save(ms, ImageFormat.Png);
base.Response.ClearContent();
base.Response.ContentType = "image/Png";
base.Response.BinaryWrite(ms.ToArray());
theGraphics.Dispose();
theBitmap.Dispose();
base.Response.End();
}

[解决办法]

C# code

        public void CreateImage(string str_ValidateCode)        {            int bmpWidth = str_ValidateCode.Length * 9;//str_ValidateCode的长度乘9            int bmpHight = 0x12;            Random newRandom = new Random();//随机数            Bitmap theBitmap = new Bitmap(bmpWidth, bmpHight);//新建一个bitmap对象            Graphics theGraphics = Graphics.FromImage(theBitmap);//获得上面对象的graphic            theGraphics.Clear(Color.White);//填充白底色            Font theFont = new Font("Verdana", 9f);//字体            //下面是在theGraphics上面画文字            for (int int_index = 0; int_index < str_ValidateCode.Length; int_index++)            {                string str_char = str_ValidateCode.Substring(int_index, 1);                Brush newBrush = new SolidBrush(this.GetRandomColor());                Point thePos = new Point(int_index * 8, 2);                theGraphics.DrawString(str_char, theFont, newBrush, (PointF)thePos);            }            MemoryStream ms = new MemoryStream();//创建内存流            theBitmap.Save(ms, ImageFormat.Png);//位图保存至流            //下面调用基类的方法，自己查去            base.Response.ClearContent();            base.Response.ContentType = "image/Png";            base.Response.BinaryWrite(ms.ToArray());            theGraphics.Dispose();//释放            theBitmap.Dispose();//释放            base.Response.End();        }