格式化json字符串

private string ConvertJsonString(string str)
{
//格式化json字符串
JsonSerializer serializer = new JsonSerializer();
TextReader tr = new StringReader(str);
JsonTextReader jtr = new JsonTextReader(tr);
object obj = serializer.Deserialize(jtr);
if (obj != null)
{
StringWriter textWriter = new StringWriter();
JsonTextWriter jsonWriter = new JsonTextWriter(textWriter)
{
Formatting = Formatting.Indented,
Indentation = 4,
IndentChar = ' '
};
serializer.Serialize(jsonWriter, obj);
return textWriter.ToString();
}
else
{
return str;
}
}