private bool raiseBeforePropertyValueChangesEvent(PropertyValueChangeEventArgs evntArgs)
{
var evntHndlrs = BeforePropertyValueChanges?.GetInvocationList();
if (evntHndlrs == null)
{
return(true);
}
foreach (var evntHndlr in evntHndlrs)
{
var handler = (BeforePropertyChangingEventHandler)evntHndlr;
var result = handler(this, evntArgs);
if (result == false)
{
return(false);
}
}
return(true);
}
/// <summary>
/// 属性通用的setter方法
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="value"></param>
/// <param name="property"></param>
/// <param name="propertyName"></param>
protected virtual void set <T>(ref T property, T value, [CallerMemberName] string propertyName = "")
{
propertyName.ShouldNotBeNullOrEmpty();
#endif
if (!Equals(property, value))
{
if (BeforePropertyValueChanges != null || AfterPropertyValueChanged != null)
{
var oldvalue = property;
var evntArgs = new PropertyValueChangeEventArgs(propertyName, oldvalue, value);
bool allowChanging = raiseBeforePropertyValueChangesEvent(evntArgs);
if (!allowChanging)
{
return;
}
setvalue(ref property, value, propertyName);
raiseAfterPropertyValueChangesEvent(evntArgs);
}
else
{
setvalue(ref property, value, propertyName);
}
}
}
private void raiseAfterPropertyValueChangesEvent(PropertyValueChangeEventArgs evntArgs)
{
AfterPropertyValueChanged?.Invoke(this, evntArgs);
}