Datatable转换为Json

/// <summary> 
/// Datatable转换为Json 
/// </summary> 
/// <param name="table">Datatable对象</param>
/// <returns>Json字符串</returns> 
public static string ToJson(DataTable dt)
    {
        StringBuilder jsonString = new StringBuilder();
        jsonString.Append("[");
        DataRowCollection drc = dt.Rows;
        for (int i = 0; i < drc.Count; i++)
        {
            jsonString.Append("{");
            for (int j = 0; j < dt.Columns.Count; j++)
            {
                string strKey = dt.Columns[j].ColumnName;
                string strValue = drc[i][j].ToString();
                Type type = dt.Columns[j].DataType;
                jsonString.Append("\"" + strKey + "\":");
                strValue = StringFormat(strValue, type);
                if (j < dt.Columns.Count - 1)
                {
                    jsonString.Append(strValue + ",");
                }
                else
                {
                    jsonString.Append(strValue);
                }
            }
            jsonString.Append("},");
        }
        if (jsonString.Length > 1)
        {
            jsonString.Remove(jsonString.Length - 1, 1);
        }
        jsonString.Append("]");
        return jsonString.ToString();
    }

//使用
string Jsonstr = "[]"; 
DataTable dt_no = new DataTable();
Jsonstr = ConvertJson.ToJson(dt_no);
string Mismatch = "{\"YWName\":\"" + "" + "\",\"Detail\":" + Jsonstr + " }";