彩票走势图

前面我为大家介绍了如何用 Aspose.Barcode 生成QR Code，Pdf417，Datamatrix和Aztec二维码（查看二维码系列教程）。今天为大家介绍二维码的常见应用，如何对Aspose.Barcode生成的二维码进行长宽比调整，如何隐藏较长的CodeText，如何改变CodeText字体大小以及如何生成多个MacroPdf417条码。

设置长宽比

Aspose.Barcode条形码中的Aspect Ratio即是长宽比。3:2Aspect Ratio表示条形码的宽是高的1.5倍，如下图：

示例代码如下：

[C#]
// Create instance of BarCodeBuilder class
BarCodeBuilder builder = new BarCodeBuilder("1234567890", Symbology.Pdf417);
// Set Aspect Ratio to 3:2 or 1.5
builder.AspectRatio = 1.5f;
// Save the barcode image to disk in PNG format
builder.Save("barcode.png");

隐藏较长的CodeText

和一维码不同，二维码包含有大量的数据。通常打印出来的二维码下面都会附一段可读的CodeText文字，这段文字对二维码的扫描是没有影响的，所以当CodeText因为太长而不能显示时，我们可以将CodeText隐藏，示例代码如下：

[C#]
Aspose.BarCode.BarCodeBuilder b;
b = new Aspose.BarCode.BarCodeBuilder();
b.SymbologyType = Aspose.BarCode.Symbology.DataMatrix;
b.CodeText = "The quick brown fox jumps over the lazy dog\n"
       + "The quick brown fox jumps over the lazy dog\n";
b.CodeLocation = Aspose.BarCode.CodeLocation.None;
b.Save(@"c:\test_datamatrix.bmp", ImageFormat.Bmp);

如果非要保留CodeText，唯一的办法就是将CodeText的字体调小，示例代码如下：

[C#]
Aspose.BarCode.BarCodeBuilder b;
b = new Aspose.BarCode.BarCodeBuilder();
b.SymbologyType = Aspose.BarCode.Symbology.DataMatrix;
b.CodeText = "The quick brown fox jumps over the lazy dog\n"
       + "The quick brown fox jumps over the lazy dog\n";
b.CodeTextFont = new System.Drawing.Font("Arial", 6f);
b.Save(@"c:\test_datamatrix.bmp", ImageFormat.Bmp);

生成多个MacroPdf417条码

当有多个CodeText值或一个很大的CodeText值时，将大的值分成多个更小的CodeText值，然后生成多个MacroPdf417条码。每个生成的条码包含 File ID 和 Segment ID，以保证能正确识别。在下面的示例中生成了4个MacroPdf417条码：

[C#]
// create instance of BarCodeBuilder class and set symbology
BarCodeBuilder builder = new BarCodeBuilder();
builder.SymbologyType = Symbology.MacroPdf417;

// create array for storing multiple barcodes
int nSize = 4;
string[] lstCodeText = new string[] { "code-1", "code-2", "code-3", "code-last" };
string strFileID = "1";

// check the listbox for getting codetext and generating the barcodes
for (int nCount = 1; nCount <= nSize; nCount++)
{
    builder.CodeText = lstCodeText[nCount - 1];
    // fileID should be same for all the generated barcodes
    builder.MacroPdf417FileID = int.Parse(strFileID);
    // assign segmentID in increasing order (1,2,3,....)
    builder.MacroPdf417SegmentID = nCount;

    // check if we reached last element yet
    if (nCount == nSize)
        builder.MacroPdf417LastSegment = true;
    else
        builder.MacroPdf417LastSegment = false;

    // save the barcode (fileid_segmentid.png)
    builder.Save(strFileID + "_" + nCount + ".png", ImageFormat.Png);
    Process.Start(strFileID + "_" + nCount + ".png");
}