c#扩展datatable转json示例

复制代码 代码如下:
namespace PadWebServices.Model
{
   public static class DataTableExtender
    {
       public static string ToJson(this DataTable dt,string tbName)  // this DataTable 标识对DataTable类的扩展
            {
                StringBuilder JsonString = new StringBuilder();
                if (dt != null && dt.Rows.Count > 0)
                {
                    JsonString.Append("{ ");
                    JsonString.Append("""+tbName+"":[ ");
                    for (int i = 0; i < dt.Rows.Count; i++)
                    {
                        JsonString.Append("{ ");
                        for (int j = 0; j < dt.Columns.Count; j++)
                        {
                            if (j < dt.Columns.Count - 1)
                            {
                                JsonString.Append(""" + dt.Columns[j].ColumnName.ToString() + "":" + """ + dt.Rows[i][j].ToString() + "",");
                            }
                            else if (j == dt.Columns.Count - 1)
                            {
                                JsonString.Append(""" + dt.Columns[j].ColumnName.ToString() + "":" + """ + dt.Rows[i][j].ToString() + """);
                            }
                        }

                       
                        if (i == dt.Rows.Count - 1)
                        {
                            JsonString.Append("} ");
                        }
                        else
                        {
                            JsonString.Append("}, ");
                        }
                    }
                    JsonString.Append("]}");
                    return JsonString.ToString();
                }
                else
                {
                    return null;
                }

            }

    }
}

在用到的时候，using扩展类所在的空间，就可以用了。

复制代码 代码如下:
[WebMethod]
public string GetSwt_yBatch()
{   
    DataTable dt = new BllSwt_yBatch().GetSwt_yBatch();
    return dt.ToJson("swt_yBatch");
}

这里的webservice返回的格式还是XML，只不过通过转成JSON的数据，在XML中是这样：

复制代码 代码如下:

  { "swt_yBatch":[ { "sDoc_c":"test1","sDocAdd_c":"test2","nBatch":"1"},
{ "sDoc_c":"test3","sDocAdd_c":"test4","nBatch":"2"}, { "sDoc_c":"test3","sDocAdd_c":"test4","nBatch":"2"} ]}

没有转成JSON的数据是这样：

复制代码 代码如下:

-
-
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-
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-
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  test1
  test2
  1
 
-
  test3
  test4
  2
 
-
  test3
  test4
  2