Webservice返回json数据格式

问题：

我将结果内容用字符串拼接成Json数据并返回的时候，会在结果前面添加xml头部，结果如下。

1. <span ><string xmlns="http://tempuri.org/">
2. {"data":[{"batchId":"B001","produceOrderId":"", "produceFactory":"","addTime":"2014/7/8 15:09:00","remark":"","parentId":""},{"batchId":"B002","produceOrderId":"生产订单2", "produceFactory":"测试公司1","addTime":"2014/7/8 8:00:00","remark":"","parentId":"B001"},{"batchId":"B003","produceOrderId":"生产订单3", "produceFactory":"测试公司2","addTime":"2014/7/8 0:00:00","remark":"","parentId":"B001"},{"batchId":"B004","produceOrderId":"生产订单4", "produceFactory":"测试公司3","addTime":"2014/7/8 0:00:00","remark":"","parentId":"B002"},{"batchId":"B005","produceOrderId":"生产订单5", "produceFactory":"测试公司4","addTime":"2014/7/8 0:00:00","remark":"","parentId":"B004"},{"batchId":"B006","produceOrderId":"生产订单6", "produceFactory":"外包公司1","addTime":"2014/7/8 0:00:00","remark":"","parentId":"B005"}]}
3. </string></span>

产生如上数据的Webservice接口代码如下。

1. <span >  [WebMethod]
2. public String GetQrCodeList(String qrCode)
3. {
4. return PriGetQrCodeList(qrCode);
5. }
6. /// <summary>
7. /// 获取关联的二维码树结构
8. /// </summary>
9. /// <param name="qrCode">产品二维码</param>
10. /// <returns></returns>
11. private String PriGetQrCodeList(String qrCode)
12. {
13. try
14. {
15. String sfull = "{{\"data\":[{0}]}}";
16. String spart = "{{\"batchId\":\"{0}\",\"produceOrderId\":\"{1}\", \"produceFactory\":\"{2}\",\"addTime\":\"{3}\",\"remark\":\"{4}\",\"parentId\":\"{5}\"}}";
17. String sData = "";
18. DataTable dt = bll.GetQrCodeList(qrCode);
19. if (dt == null || dt.Rows.Count == 0) return "";
20. for (int i = 0; i < dt.Rows.Count; i++)
21. {
22. sData += (String.Format(spart,
23. dt.Rows[i]["BatchId"].ToString(),
24. dt.Rows[i]["ProduceOrderId"].ToString(),
25. dt.Rows[i]["ProduceFactory"].ToString(),
26. dt.Rows[i]["AddTime"].ToString(),
27. dt.Rows[i]["Remark"].ToString(),
28. dt.Rows[i]["ParentId"].ToString()) + ",");
29. }
30. return String.Format(sfull, sData.TrimEnd(','));
31. }
32. catch (Exception)
33. {
34. return "";
35. }
36. }</span>

解决方案：

改变数据的返回方式，用 Context.Response.Write代替return 语句，修改GetQrCodeList方法如下即可返回正确的Json格式数据。

1. <span >    [WebMethod]
2. public void GetQrCodeList(String qrCode)
3. {
4. Context.Response.Charset = "GB2312"; //设置字符集类型
5. Context.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
6. Context.Response.Write(PriGetQrCodeList(qrCode));
7. Context.Response.End();
8. }</span>

返回结果如下：

1. <span >{"data":[{"batchId":"B001","produceOrderId":"", "produceFactory":"","addTime":"2014/7/8 15:09:00","remark":"","parentId":""},{"batchId":"B002","produceOrderId":"生产订单2", "produceFactory":"测试公司1","addTime":"2014/7/8 8:00:00","remark":"","parentId":"B001"},{"batchId":"B003","produceOrderId":"生产订单3", "produceFactory":"测试公司2","addTime":"2014/7/8 0:00:00","remark":"","parentId":"B001"},{"batchId":"B004","produceOrderId":"生产订单4", "produceFactory":"测试公司3","addTime":"2014/7/8 0:00:00","remark":"","parentId":"B002"},{"batchId":"B005","produceOrderId":"生产订单5", "produceFactory":"测试公司4","addTime":"2014/7/8 0:00:00","remark":"","parentId":"B004"},{"batchId":"B006","produceOrderId":"生产订单6", "produceFactory":"外包公司1","addTime":"2014/7/8 0:00:00","remark":"","parentId":"B005"}]}</span>