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。

<span ><string xmlns="http://tempuri.org/">
{"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"}]}
</string></span>

产生如上数据的Webservice接口代码如下。

<span >  [WebMethod]
    public String GetQrCodeList(String qrCode)
    {

        return PriGetQrCodeList(qrCode);
    }

    /// <summary>
    /// 获取关联的二维码树结构
    /// </summary>
    /// <param name="qrCode">产品二维码</param>
    /// <returns></returns>
    private String PriGetQrCodeList(String qrCode)
    {
        try
        {
            String sfull = "{{"data":[{0}]}}";
            String spart = "{{"batchId":"{0}","produceOrderId":"{1}", "produceFactory":"{2}","addTime":"{3}","remark":"{4}","parentId":"{5}"}}";
            String sData = "";
            DataTable dt = bll.GetQrCodeList(qrCode);
            if (dt == null || dt.Rows.Count == 0) return "";
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                sData += (String.Format(spart,
                    dt.Rows[i]["BatchId"].ToString(),
                    dt.Rows[i]["ProduceOrderId"].ToString(),
                    dt.Rows[i]["ProduceFactory"].ToString(),
                    dt.Rows[i]["AddTime"].ToString(),
                    dt.Rows[i]["Remark"].ToString(),
                    dt.Rows[i]["ParentId"].ToString()) + ",");
            }
            return String.Format(sfull, sData.TrimEnd(','));
        }
        catch (Exception)
        {
            return "";
        }
    }</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。

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

返回结果如下：

<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>