/// <summary>
/// 如果测试对象为空，则返回一个默认对象
/// </summary>
/// <typeparam name="T">对象类型</typeparam>
/// <param name="testObject">测试对象</param>
/// <param name="objectForNothing">对象为空时返回的默认对象</param>
/// <param name="nothingType">空对象类型</param>
/// <returns>如果对象为空，返回一个默认对象；否则，返回对象本身</returns>
public static T IfNothing <T>(this T testObject, T objectForNothing, NothingType nothingType = NothingType.All)
{
if (IsNullOrEmpty(testObject, nothingType))
{
return(objectForNothing);
}
return(testObject);
}
/// <summary>
/// 对象是否为空
/// </summary>
/// <param name="testObject">待测试对象</param>
/// <param name="nothingType">空对象类型</param>
/// <returns>对象为空返回True，否则返回False</returns>
public static bool IsNullOrEmpty(this object testObject, NothingType nothingType = NothingType.All)
{
// 对引用判断
if ((int)(nothingType & NothingType.Reference) != 0)
{
if (testObject == null)
{
return(true);
}
}
// 对DBNull的判断
if ((int)(nothingType & NothingType.DBNull) != 0)
{
if (testObject == Convert.DBNull)
{
return(true);
}
}
// 对List的判断
if ((int)(nothingType & NothingType.List) != 0)
{
if (testObject is ICollection && (testObject as ICollection).Count == 0)
{
return(true);
}
}
// 对String的判断
if ((int)(nothingType & NothingType.String) != 0)
{
if (testObject is string && (testObject as string) == String.Empty)
{
return(true);
}
}
return(false);
}
/// <summary>
/// 对象是否为不空
/// </summary>
/// <param name="testObject">待测试对象</param>
/// <param name="nothingType">空对象类型</param>
/// <returns>对象为空返回True，否则返回False</returns>
public static bool IsNotNullOrEmpty(this object testObject, NothingType nothingType = NothingType.All)
{
return(!IsNullOrEmpty(testObject, nothingType));
}
public object Read(NothingType nothingType) => null;
public void Write(NothingType nothingType, object value)
{
}