/// <summary>
/// DataTable 转JSON 速度最快
/// </summary>
/// <example>
/// <code>
/// Data.GetDataTable("Select MemberID,RealName from UC_Member").ToDataTableJson();
/// </code>
/// </example>
/// <param name="dt">DataTable</param>
/// <returns>JSON字符串</returns>
public static string ToDataTableJson(this DataTable dt)
{
if (dt.IsNull())
{
return("[]");
}
StringBuilder jsonHtml = new StringBuilder();
jsonHtml.Append("[");
JavaScriptSerializerString serializer = new JavaScriptSerializerString();
foreach (DataRow row in dt.Rows)
{
jsonHtml.Append("{");
foreach (DataColumn col in dt.Columns)
{
jsonHtml.AppendFormat("\"{0}\":{1},", col.ColumnName, serializer.Serialize(row[col]));
}
jsonHtml.Remove(jsonHtml.Length - 1, 1);
jsonHtml.Append("},");
}
dt.Dispose(); dt = null;
if (jsonHtml.Length > 1)
{
jsonHtml.Remove(jsonHtml.Length - 1, 1);
}
jsonHtml.Append("]");
return(jsonHtml.ToString());
}
/// <summary>
/// IDataReader 转JSON 速度最快
/// </summary>
/// <example>
/// <code>
/// Data.GetDbDataReader("Select MemberID,RealName from UC_Member").ToDataReaderJson(true);
/// </code>
/// </example>
/// <param name="dr">IDataReader扩展</param>
/// <param name="isClose">是否关闭DataReader</param>
/// <returns>转JSON</returns>
public static string ToDataReaderJson(this IDataReader dr, bool isClose)
{
if (dr.IsNull())
{
return("[]");
}
StringBuilder jsonHtml = new StringBuilder();
jsonHtml.Append("[");
JavaScriptSerializerString serializer = new JavaScriptSerializerString();
while (dr.Read())
{
jsonHtml.Append("{");
for (int i = 0, len = dr.FieldCount; i < len; i++)
{
jsonHtml.AppendFormat("\"{0}\":{1},", dr.GetName(i), serializer.Serialize(dr[i]));
}
jsonHtml.Remove(jsonHtml.Length - 1, 1);
jsonHtml.Append("},");
}
if (isClose)
{
dr.Close(); dr.Dispose(); dr = null;
}
if (jsonHtml.Length > 1)
{
jsonHtml.Remove(jsonHtml.Length - 1, 1);
}
jsonHtml.Append("]");
return(jsonHtml.ToString());
}
/// <summary>
/// DataTable 转JSON 速度最快
/// </summary>
/// <param name="dt">DataTable</param>
/// <param name="fields">字段列表</param>
/// <param name="alias">别名</param>
/// <returns>JSON字符串</returns>
public static string ToJson(this DataTable dt, int[] fields, string[] alias)
{
if (dt.IsNull())
{
return("[]");
}
if (alias.IsNull() || fields.Length != alias.Length)
{
Msg.WriteEnd("参数错误！");
}
if (fields.IsNull() || fields.Length == 0)
{
return(dt.ToDataTableJson());
}
JavaScriptSerializerString serializer = new JavaScriptSerializerString();
StringBuilder jsonHtml = new StringBuilder();
jsonHtml.Append("[");
foreach (DataRow row in dt.Rows)
{
jsonHtml.Append("{");
int i = 0;
foreach (int col in fields)
{
jsonHtml.AppendFormat("\"{0}\":{1},", alias[i], serializer.Serialize(row[col])); i++;
}
jsonHtml.Remove(jsonHtml.Length - 1, 1);
jsonHtml.Append("},");
}
dt.Dispose(); dt = null;
if (jsonHtml.Length > 1)
{
jsonHtml.Remove(jsonHtml.Length - 1, 1);
}
jsonHtml.Append("]");
return(jsonHtml.ToString());
}
/// <summary>
/// IDataReader 转JSON 速度最快
/// </summary>
/// <param name="dr">IDataReader扩展</param>
/// <param name="fields">字段</param>
/// <param name="alias">别名</param>
/// <returns>转JSON</returns>
public static string ToJson(this IDataReader dr, string[] fields, string[] alias)
{
if (dr.IsNull())
{
return("[]");
}
if (alias.IsNull() || fields.Length != alias.Length)
{
alias = fields;
}
if (fields.IsNull() || fields.Length == 0)
{
return(dr.ToJson());
}
JavaScriptSerializerString serializer = new JavaScriptSerializerString();
StringBuilder jsonHtml = new StringBuilder();
jsonHtml.Append("[");
while (dr.Read())
{
jsonHtml.Append("{");
for (int i = 0, len = fields.Length; i < len; i++)
{
jsonHtml.AppendFormat("\"{0}\":{1},", alias[i], serializer.Serialize(dr[fields[i]]));
}
jsonHtml.Remove(jsonHtml.Length - 1, 1);
jsonHtml.Append("},");
}
dr.Close(); dr.Dispose(); dr = null;
if (jsonHtml.Length > 1)
{
jsonHtml.Remove(jsonHtml.Length - 1, 1);
}
jsonHtml.Append("]");
return(jsonHtml.ToString());
}
