绘制图像后右侧存在巨大的空白。想要摆脱它

Question

我正在使用以下代码项目来构建一个 asp.net 网站，到目前为止一切都很好。我唯一的问题是生成条形码后，条形码右侧存在巨大的空白。我一直在玩这个，但无法解决它。

详细信息如下：

代码项目文章链接：http://www.codeproject .com/KB/aspnet/AspBarCodes.aspx?msg=3543809

字体副本位于：http://trussvillemethodist.web01.appliedi-labs.net/IDAutomationHC39M.ttf

          //Working Path
        string sWorkPath = "";
        sWorkPath = this.Context.Server.MapPath("");

        //Fonts
        PrivateFontCollection fnts = new PrivateFontCollection();
        fnts.AddFontFile(sWorkPath + @"\IDAutomationHC39M.ttf");
        FontFamily fntfam = new FontFamily("IDAutomationHC39M", fnts);
        Font oFont = new Font(fntfam, 18);

        // Get the Requested code sent from the previous page.
        string strCode = Request["code"].ToString();

        //Graphics
        //I don't know what to set the width to as I can't call the MeasureString without creating the Graphics object.
        Bitmap oBitmaptemp = new Bitmap(40, 100);
        Graphics oGraphicstemp = Graphics.FromImage(oBitmaptemp);
        int w = (int)oGraphicstemp.MeasureString(strCode, oFont).Width + 4;

        // Create a bitmap object of the width that we calculated and height of 100
        Bitmap oBitmap = new Bitmap(w, 100);

        // then create a Graphic object for the bitmap we just created.
        Graphics oGraphics = Graphics.FromImage(oBitmap);

        // Let's create the Point and Brushes for the barcode
        PointF oPoint = new PointF(2f, 2f);
        SolidBrush oBrushWrite = new SolidBrush(Color.Black);
        SolidBrush oBrush = new SolidBrush(Color.White);

        // Now lets create the actual barcode image
        // with a rectangle filled with white color
        oGraphics.FillRectangle(oBrush, 0, 0, w, 100);

        // We have to put prefix and sufix of an asterisk (*),
        // in order to be a valid barcode
        oGraphics.DrawString("*" + strCode + "*", oFont, oBrushWrite, oPoint);

        // Then we send the Graphics with the actual barcode
        Response.ContentType = "image/gif";
        oBitmap.Save(Response.OutputStream, ImageFormat.Gif);

        oBitmap.Dispose();
        oGraphics.Dispose();
        oBrush.Dispose();
        oFont.Dispose();

Answer 1

该代码仅假设每个字符 40 个像素，这就是为什么文本右侧会留下大量图像的原因。您可以使用 MeasureString 方法来测量文本的大小，并使用它来创建正确大小的图像：

int w = (int)oGraphics.MeasureString("*123$10.00*", oFont).Width + 4;

我注意到您没有处置正在使用的任何对象。需要处理Graphics、Bitmap、SolidBrush和Font对象。

您可能还想考虑使用 GIF 图像而不是 JPEG，它更适合此类图形。