各数据类型转json

/// <summary>
/// JSON帮助类
/// </summary>
public class JsonHelper
{
#region 通用方法
/// <summary>
/// 格式化字符型、日期型、布尔型
/// </summary>
public static string StringFormat(string str, Type type)
{
if (type == typeof(string))
{
str = StringFilter(str);
str = """ + str + """;
}
else if (type == typeof(DateTime) || type == typeof(DateTime?))
{
str = """ + str + """;
}
else if (type == typeof(bool))
{
str = str.ToLower();
}
else if (type == typeof(Guid))
{
str = """ + str + """;
}
else if (type != typeof(string) && string.IsNullOrEmpty(str))
{
str = """ + str + """;
}
return str;
}

/// <summary>
/// 过滤字符串
/// </summary>
public static string StringFilter(string str)
{
StringBuilder sb = new StringBuilder();
for (int i = 0; i < str.Length; i++)
{
char c = str.ToCharArray()[i];
switch (c)
{
case '"':
sb.Append("\""); break;
case '\':
sb.Append("\\"); break;
case '/':
sb.Append("\/"); break;
case '':
sb.Append("\b"); break;
case 'f':
sb.Append("\f"); break;
case ' ':
sb.Append("\n"); break;
case ' ':
sb.Append("\r"); break;
case ' ':
sb.Append("\t"); break;
default:
sb.Append(c); break;
}
}
return sb.ToString();
}
#endregion

#region 列转json
/// <summary>
/// 列转json
/// </summary>
/// <param name="dt">表</param>
/// <param name="r">列</param>
public static string ColumnToJson(DataTable dt, int r)
{
StringBuilder strSql = new StringBuilder();
for (int i = 0; i < dt.Rows.Count; i++)
{
strSql.Append(dt.Rows[i][r]);
strSql.Append(",");
}
return strSql.ToString().Trim(',');
}
#endregion

#region 对象转json
/// <summary>
/// 对象转json
/// </summary>
public static string ToJson(object jsonObject)
{
StringBuilder sb = new StringBuilder();
sb.Append("{");
PropertyInfo[] propertyInfo = jsonObject.GetType().GetProperties();
for (int i = 0; i < propertyInfo.Length; i++)
{
object objectValue = propertyInfo[i].GetGetMethod().Invoke(jsonObject, null);
Type type = propertyInfo[i].PropertyType;
string strValue = objectValue.ToString();
strValue = StringFormat(strValue, type);
sb.Append(""" + propertyInfo[i].Name + "":");
sb.Append(strValue + ",");
}
sb.Remove(sb.Length - 1, 1);
sb.Append("}");
return sb.ToString();
}
#endregion

#region list转json
/// <summary>
/// list转json
/// </summary>
public static string ListToJson<T>(IList<T> list)
{
object obj = list[0];
return ListToJson<T>(list, obj.GetType().Name);
}

private static string ListToJson<T>(IList<T> list, string JsonName)
{
StringBuilder Json = new StringBuilder();
if (string.IsNullOrEmpty(JsonName))
JsonName = list[0].GetType().Name;
Json.Append("{"" + JsonName + "":[");
if (list.Count > 0)
{
for (int i = 0; i < list.Count; i++)
{
T obj = Activator.CreateInstance<T>();
PropertyInfo[] pi = obj.GetType().GetProperties();
Json.Append("{");
for (int j = 0; j < pi.Length; j++)
{
Type type = pi[j].GetValue(list[i], null).GetType();
Json.Append(""" + pi[j].Name.ToString() + "":" + StringFormat(pi[j].GetValue(list[i], null).ToString(), type));
if (j < pi.Length - 1)
{
Json.Append(",");
}
}
Json.Append("}");
if (i < list.Count - 1)
{
Json.Append(",");
}
}
}
Json.Append("]}");
return Json.ToString();
}
#endregion

#region 对象集合转换为json
/// <summary>
/// 对象集合转换为json
/// </summary>
/// <param name="array">对象集合</param>
/// <returns>json字符串</returns>
public static string ToJson(IEnumerable array)
{
string jsonString = "[";
foreach (object item in array)
{
jsonString += ToJson(item) + ",";
}
jsonString = jsonString.Substring(0, jsonString.Length - 1);
return jsonString + "]";
}
#endregion

#region 普通集合转换Json
/// <summary>
/// 普通集合转换Json
/// </summary>
/// <param name="array">集合对象</param>
/// <returns>Json字符串</returns>
public static string ToArrayString(IEnumerable array)
{
string jsonString = "[";
foreach (object item in array)
{
jsonString = ToJson(item.ToString()) + ",";
}
jsonString.Remove(jsonString.Length - 1, jsonString.Length);
return jsonString + "]";
}
#endregion

#region DataSet转换为Json
/// <summary>
/// DataSet转换为Json
/// </summary>
/// <param name="dataSet">DataSet对象</param>
/// <returns>Json字符串</returns>
public static string ToJson(DataSet dataSet)
{
string jsonString = "{";
foreach (DataTable table in dataSet.Tables)
{
jsonString += """ + table.TableName + "":" + ToJson(table) + ",";
}
jsonString = jsonString.TrimEnd(',');
return jsonString + "}";
}
#endregion

#region Datatable转换为Json
/// <summary>
/// Datatable转换为Json
/// </summary>
public static string ToJson(DataTable dt)
{
if (dt.Rows.Count > 0)
{
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("},");
}
jsonString.Remove(jsonString.Length - 1, 1);
jsonString.Append("]");
return jsonString.ToString();
}
else
return "[]";
}

/// <summary>
/// DataTable转换为Json
/// </summary>
public static string ToJson(DataTable dt, string jsonName)
{
StringBuilder Json = new StringBuilder();
if (string.IsNullOrEmpty(jsonName))
jsonName = dt.TableName;
Json.Append("{"" + jsonName + "":[");
if (dt.Rows.Count > 0)
{
for (int i = 0; i < dt.Rows.Count; i++)
{
Json.Append("{");
for (int j = 0; j < dt.Columns.Count; j++)
{
Type type = dt.Rows[i][j].GetType();
Json.Append(""" + dt.Columns[j].ColumnName.ToString() + "":" + StringFormat(dt.Rows[i][j].ToString(), type));
if (j < dt.Columns.Count - 1)
Json.Append(",");
}
Json.Append("}");
if (i < dt.Rows.Count - 1)
Json.Append(",");
}
}
Json.Append("]}");
return Json.ToString();
}
#endregion

#region DataReader转换为Json
/// <summary>
/// DataReader转换为Json
/// </summary>
/// <param name="dataReader">DataReader对象</param>
/// <returns>Json字符串</returns>
public static string ToJson(DbDataReader dataReader)
{
StringBuilder jsonString = new StringBuilder();
jsonString.Append("[");
while (dataReader.Read())
{
jsonString.Append("{");
for (int i = 0; i < dataReader.FieldCount; i++)
{
Type type = dataReader.GetFieldType(i);
string strKey = dataReader.GetName(i);
string strValue = dataReader[i].ToString();
jsonString.Append(""" + strKey + "":");
strValue = StringFormat(strValue, type);
if (i < dataReader.FieldCount - 1)
jsonString.Append(strValue + ",");
else
jsonString.Append(strValue);
}
jsonString.Append("},");
}
dataReader.Close();
jsonString.Remove(jsonString.Length - 1, 1);
jsonString.Append("]");
return jsonString.ToString();
}
#endregion

#region 返回错误
public static string error()
{
DataTable dt = new DataTable();
dt.Columns.Add("error", typeof(int));
DataRow dr = dt.NewRow();
dr["error"] = 1;
dt.Rows.Add(dr);
return ToJson(dt);
}
#endregion

}