前面我為大家介紹了如何用 Aspose.Barcode 生成QR Code，Pdf417，Datamatrix和Aztec二維碼（查看二維碼系列教程）。今天為大家介紹二維碼的常見應用，如何對Aspose.Barcode生成的二維碼進行長寬比調整，如何隱藏較長的CodeText，如何改變CodeText字體大小以及如何生成多個MacroPdf417條碼。

設置長寬比

Aspose.Barcode條形碼中的Aspect Ratio即是長寬比。3:2Aspect Ratio表示條形碼的寬是高的1.5倍，如下圖：

示例代碼如下：

[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");

隱藏較長的CodeText

和一維碼不同，二維碼包含有大量的數據。通常打印出來的二維碼下面都會附一段可讀的CodeText文字，這段文字對二維碼的掃描是沒有影響的，所以當CodeText因為太長而不能顯示時，我們可以將CodeText隱藏，示例代碼如下：

[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，唯一的辦法就是將CodeText的字體調小，示例代碼如下：

[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);

生成多個MacroPdf417條碼

當有多個CodeText值或一個很大的CodeText值時，將大的值分成多個更小的CodeText值，然后生成多個MacroPdf417條碼。每個生成的條碼包含 File ID 和 Segment ID，以保證能正確識別。在下面的示例中生成了4個MacroPdf417條碼：

[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");
}