Ext.Net 1.2.0_演示 Ext.Net+Barcode 封装条形码控件

本文内容

概述
演示利用 Ext.Net + Barcode 封装条形码控件
运行结果
修改记录
 

概述

最近项目需要条形码，因为已经为每个业务都创建了编码，只要把编码生成相应的条形码即可。再者，不想在相应的表添加一个字段，既要保存编码，又要保存编码对应的条形码，保存其二进制数据，用的时候再生成条形码（图片）。

需要的时候再生成也可以。而且在页面显示图片，要么生成临时的条形码图片，用完再删；要么向客户端直接发送二进制流，并设置 HTTP 头 content-type="image/jpeg"。第一个方法有点麻烦；而第二个方法，打印报表怎么办？报表可很多来自不同表不同字段的数据等等。

那就把条形码搞成一个控件吧，反正浏览器是可以打印的。

本文演示如何利用 Ext.Net.Panel 和 Barcode 项目创建条形码。封装后如下所示：

[code][code]<cc1:MyBarcode ID="MyBarcode1" runat="server" CustomBarCodeType="CODE39" CustomData="D012659834"

Title="CODE39 条形码">

</cc1:MyBarcode>

[/code]
[/code]

其中，

MyBarcode 控件为自定义条形码控件；

CustomBarCodeType 属性是条形码类型；

CustomData 属性是要生成条形码的字符串。

 

演示利用 Ext.Net + Barcode 封装条形码控件

解决方案结构





 

自定义 MyBarcode UI

[code]
[code]using System;

using Ext.Net;

using System.ComponentModel;

namespace MyExtNet.Control

{

public partial class MyBarcode

{

[DefaultValue("")]

[Description("条形码类型)")]

public string CustomBarCodeType

{

get

{

return (string)this.ViewState["CustomBarCodeType"] ?? "";

}

set { this.ViewState["CustomBarCodeType"] = value; }

}

[DefaultValue("")]

[Description("数据")]

public string CustomData

{

get

{

return (string)this.ViewState["CustomData"] ?? "";

}

set { this.ViewState["CustomData"] = value; }

}

public MyBarcode()

{

this.AnimCollapse = false;

this.AutoDataBind = false;

}

protected override void OnPreRender(EventArgs e)

{

base.OnPreRender(e);

if (this.CustomBarCodeType.Length <= 0)

throw new NullReferenceException("Invalid Param.");

if (this.Width.IsEmpty)

this.Width = System.Web.UI.WebControls.Unit.Pixel(250);

if (this.Height.IsEmpty)

this.Height = System.Web.UI.WebControls.Unit.Pixel(80);

this.AutoLoad.Url = "~/BarcodeHandler.ashx";

this.AutoLoad.Mode = Ext.Net.LoadMode.IFrame;

this.AutoLoad.Method = Ext.Net.HttpMethod.GET;

this.AutoLoad.Params.Add(new Parameter() { Name = "Data", Value = this.CustomData, Mode = Ext.Net.ParameterMode.Value });

this.AutoLoad.Params.Add(new Parameter() { Name = "BarCodeType", Value = this.CustomBarCodeType, Mode = Ext.Net.ParameterMode.Value });

this.AutoLoad.Params.Add(new Parameter() { Name = "Width", Value = this.Width.Value.ToString(), Mode = Ext.Net.ParameterMode.Value });

this.AutoLoad.Params.Add(new Parameter() { Name = "Height", Value = this.Height.Value.ToString(), Mode = Ext.Net.ParameterMode.Value });

}

}

}

[/code]
[/code]

 

自定义 MyBarcode Logic

[code]
[code]using System;

using Ext.Net;

using System.Web;

namespace MyExtNet.Control

{

public partial class MyBarcode : Ext.Net.Panel

{

}

}

[/code]
[/code]

说明

MyBarcode UI 和 MyBarcode Logic 是一个分部类 MyBarcode，对于自定义 WebControl 来说，将控件的 UI 部分和逻辑部分分别实现，很清晰。本例的 MyBarcode Logic 部分没内容。

 

自定义处理程序 BarcodeHandler.ashx

该处理程序根据指定字符串生成条形码，并发送给客户端。

[code]
[code]using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Services;

using System.Drawing;

using System.Drawing.Imaging;

using System.IO;

namespace ExtNetBar

{

/// <summary>

/// $codebehindclassname$ 的摘要说明

/// </summary>

//[WebService(Namespace = "http://tempuri.org/")]

//[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]

public class BarcodeHandler : IHttpHandler

{

private ImageFormat _imageFormat = ImageFormat.Jpeg;

HttpResponse _response;

HttpRequest _request;

string data;

BarcodeLib.BarCodeType barCodeType;

public void ProcessRequest(HttpContext context)

{

_response = context.Response;

_request = context.Request;

try

{

data = _request.QueryString["Data"].ToString();

if (_request.QueryString["BarCodeType"].ToString().Length > 0)

barCodeType = (BarcodeLib.BarCodeType)Enum.Parse(typeof(BarcodeLib.BarCodeType), _request.QueryString["BarCodeType"].ToString());

else

barCodeType = BarcodeLib.BarCodeType.CODE128;

int width = (int)(Convert.ToDouble(_request.QueryString["Width"].ToString()));

int height = (int)Convert.ToDouble(_request.QueryString["Height"].ToString());

Bitmap bitMap = (Bitmap)BarcodeLib.Barcode.DoEncode(barCodeType, data, width, height);

WriteImageToStream(bitMap);

}

catch (Exception ex)

{

WriteImageToStream(CreateErrorBitmap(ex.Message));

}

}

private Bitmap CreateErrorBitmap(string errMessage)

{

int width = 300;

int height = 100;

Bitmap errBitmap = new Bitmap(width, height);

Graphics g = Graphics.FromImage(errBitmap);

StringFormat strFormat = new StringFormat();

strFormat.Alignment = StringAlignment.Center;

strFormat.LineAlignment = StringAlignment.Center;

g.FillRectangle(Brushes.White, 0, 0, width, height);

g.DrawRectangle(new Pen(Brushes.LightGray, 1), new Rectangle(0, 28, width - 1, height - 33));

strFormat.Alignment = StringAlignment.Center;

strFormat.LineAlignment = StringAlignment.Near;

g.DrawString("Barcode Generator Error", new Font("Arial", 10, FontStyle.Bold), Brushes.Red, new Rectangle(0, 5, width, 15), strFormat);

strFormat.Alignment = StringAlignment.Center;

strFormat.LineAlignment = StringAlignment.Center;

switch (errMessage)

{

case "Wrong character":

errMessage = "Input data contains unsupported characters - select another barcode type or correct your input data.";

break;

case "Wrong number of input characters":

errMessage = "This barcode needs a specific number of input characters - correct your data.";

break;

default:

break;

}

g.DrawString(errMessage, new Font("Arial", 10), Brushes.Red, new Rectangle(8, 28, width - 16, height - 35), strFormat);

return errBitmap;

}

private void WriteImageToStream(Bitmap bitMap)

{

_response.ClearContent();

_response.AddHeader("Content-type", "image/jpeg");

bitMap.Save(_response.OutputStream, _imageFormat);

}

public bool IsReusable

{

get

{

return false;

}

}

}

}

[/code]
[/code]

 

创建页面

[code]
[code]<%@ Page Language="C#" %>

<%@ Register Assembly="Ext.Net" Namespace="Ext.Net" TagPrefix="ext" %>

<%@ Register Assembly="MyExtNet.Control" Namespace="MyExtNet.Control" TagPrefix="cc1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">

<title></title>

<script runat="server"> 

protected void Page_Load(object sender, EventArgs e)

 {

if (!X.IsAjaxRequest)

 {

this.MyBarcode6.CustomBarCodeType = "UPCA";

this.MyBarcode6.CustomData = "101265983434";

 }

 }

</script>

</head>

<body>

<form id="form1" runat="server">

<ext:ResourceManager ID="ResourceManager1" runat="server">

</ext:ResourceManager>

<cc1:MyBarcode ID="MyBarcode1" runat="server" CustomBarCodeType="CODE39" CustomData="D012659834"

    Title="CODE39 条形码">

</cc1:MyBarcode>

<cc1:MyBarcode ID="MyBarcode2" runat="server" CustomBarCodeType="CODE93" CustomData="D012659834"

   Title=" CODE93 条形码">

</cc1:MyBarcode>

<cc1:MyBarcode ID="MyBarcode3" runat="server" CustomBarCodeType="Codabar" CustomData="A90126598D"

   Title=" Codabar 条形码">

</cc1:MyBarcode>

<cc1:MyBarcode ID="MyBarcode4" runat="server" CustomBarCodeType="ISBN" CustomData="1012659834"

   Title="ISBN 条形码">

</cc1:MyBarcode>

<cc1:MyBarcode ID="MyBarcode5" runat="server" CustomBarCodeType="UPCA" CustomData="101265983434"

   Title="UPCA 条形码">

</cc1:MyBarcode>

<cc1:MyBarcode ID="MyBarcode6" runat="server" Title="UPCA 条形码">

</cc1:MyBarcode>

</form>

</body>

</html>

[/code]
[/code]

其中，

ID 为 MyBarcode1，创建 CODE39 条形码；

ID 为 MyBarcode2，创建 CODE93 条形码；

ID 为 MyBarcode3，创建 Codebar 条形码；

ID 为 MyBarcode4，创建 ISBN 条形码；

ID 为 MyBarcode5，创建 UPCA 条形码，利用标记创建；

ID 为 MyBarcode6，创建 UPCA 条形码，后台创建。

 

运行结果

 

修改记录

第一次 2012-1-10 [UPDATE] 概述

 

下载 Demo