利用C#產生Code39條碼BarCode並顯示在網頁上
- 2008-11-02
- 43851
- 0
利用C#產生Code39條碼並不難，網路上不少範例，但在demo今天使用的時候出了一點小問題，因為demo想應用在線上的會員卡製作，可是Bitmap不知道怎麼顯示在網頁上，找了Google絕大多數都是winform的，因此換個想法存到記憶體就好啦，有需要類似應用的可以參考看看。
二話不說，直接給code(本範例檔名為code39.ashx)
public void ProcessRequest(HttpContext context)
{
string sCode = string.Empty;
//清除該頁輸出緩存，設置該頁無緩存
context.Response.Buffer = true;
context.Response.ExpiresAbsolute = System.DateTime.Now.AddMilliseconds(0);
context.Response.Expires = 0;
context.Response.CacheControl = "no-cache";
context.Response.AppendHeader("Pragma", "No-Cache");
//將Code39條碼寫入記憶體流，並將其以 "image/Png" 格式輸出
MemoryStream oStream = new MemoryStream();
try
{
Bitmap oBmp = GetCode39(context.Request.QueryString["id"]);
oBmp.Save(oStream, System.Drawing.Imaging.ImageFormat.Png);
oBmp.Dispose();
context.Response.ClearContent();
context.Response.ContentType = "image/Png";
context.Response.BinaryWrite(oStream.ToArray());
}
finally
{
//釋放資源
oStream.Dispose();
}
}
public bool IsReusable
{
get
{
return false;
}
}
private Bitmap GetCode39(string strSource)
{
int x = 5; //左邊界
int y = 0; //上邊界
int WidLength = 2; //粗BarCode長度
int NarrowLength = 1; //細BarCode長度
int BarCodeHeight = 24; //BarCode高度
int intSourceLength = strSource.Length;
string strEncode = "010010100"; //編碼字串 初值為 起始符號 *
string AlphaBet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. $/+%*"; //Code39的字母
string[] Code39 = //Code39的各字母對應碼
{
/**//* 0 */ "000110100",
/**//* 1 */ "100100001",
/**//* 2 */ "001100001",
/**//* 3 */ "101100000",
/**//* 4 */ "000110001",
/**//* 5 */ "100110000",
/**//* 6 */ "001110000",
/**//* 7 */ "000100101",
/**//* 8 */ "100100100",
/**//* 9 */ "001100100",
/**//* A */ "100001001",
/**//* B */ "001001001",
/**//* C */ "101001000",
/**//* D */ "000011001",
/**//* E */ "100011000",
/**//* F */ "001011000",
/**//* G */ "000001101",
/**//* H */ "100001100",
/**//* I */ "001001100",
/**//* J */ "000011100",
/**//* K */ "100000011",
/**//* L */ "001000011",
/**//* M */ "101000010",
/**//* N */ "000010011",
/**//* O */ "100010010",
/**//* P */ "001010010",
/**//* Q */ "000000111",
/**//* R */ "100000110",
/**//* S */ "001000110",
/**//* T */ "000010110",
/**//* U */ "110000001",
/**//* V */ "011000001",
/**//* W */ "111000000",
/**//* X */ "010010001",
/**//* Y */ "110010000",
/**//* Z */ "011010000",
/**//* - */ "010000101",
/**//* . */ "110000100",
/**//*' '*/ "011000100",
/**//* $ */ "010101000",
/**//* / */ "010100010",
/**//* + */ "010001010",
/**//* % */ "000101010",
/**//* * */ "010010100"
};
strSource = strSource.ToUpper();
//實作圖片
Bitmap objBitmap = new Bitmap(
((WidLength * 3 + NarrowLength * 7) * (intSourceLength + 2)) + (x * 2),
BarCodeHeight + (y * 2));
Graphics objGraphics = Graphics.FromImage(objBitmap); //宣告GDI+繪圖介面
//填上底色
objGraphics.FillRectangle(Brushes.White, 0, 0, objBitmap.Width, objBitmap.Height);
for (int i = 0; i < intSourceLength; i++)
{
//檢查是否有非法字元
if (AlphaBet.IndexOf(strSource[i]) == -1 || strSource[i] == '*')
{
objGraphics.DrawString("含有非法字元",
SystemFonts.DefaultFont, Brushes.Red, x, y);
return objBitmap;
}
//查表編碼
strEncode = string.Format("{0}0{1}", strEncode,
Code39[AlphaBet.IndexOf(strSource[i])]);
}
strEncode = string.Format("{0}0010010100", strEncode); //補上結束符號 *
int intEncodeLength = strEncode.Length; //編碼後長度
int intBarWidth;
for (int i = 0; i < intEncodeLength; i++) //依碼畫出Code39 BarCode
{
intBarWidth = strEncode[i] == '1' ? WidLength : NarrowLength;
objGraphics.FillRectangle(i % 2 == 0 ? Brushes.Black : Brushes.White,
x, y, intBarWidth, BarCodeHeight);
x += intBarWidth;
}
return objBitmap;
}
需要先using System.Drawing、System.IO
在頁面上的呼叫很簡單
<asp:Image ID="Image1" runat="server" ImageUrl="~/code39.ashx?id=12" /> id就是你要產生codebar的字串
- http://blog.blueshop.com.tw/timothychi/archive/2006/12/22/48835.aspx
- http://www.dotblogs.com.tw/jeff377/archive/2008/10/29/5818.aspx
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