protected bool ChangeValue(int value, ValueChangeReason reason)
{
// 对设置值进行有效性检查
if (value > this.MaxValue)
{
value = this.MaxValue;
}
if (value < this.MinValue)
{
value = this.MinValue;
}
// 数值没有变化？
int oldValue = this.Value;
if (value == oldValue)
{
// 只需要更新数据显示就可以了
if (reason != ValueChangeReason.Keyboard)
{
SetShownText(ValueToString(value));
}
return(true);
}
// 发出通知，查看是否可以修改？
if (OnValueChanging != null)
{
ValueChangingArgs e = new ValueChangingArgs(reason, oldValue, value);
OnValueChanging.Invoke(this, e);
if (e.rejectChange)
{
return(false);
}
// 可以通过 Changing 事件设置值
value = e.newValue;
}
// 真正修改数据
if (reason == ValueChangeReason.Keyboard && (!internalChange) &&
StringToValue(this.txtNumeric.Text, out oldValue) && oldValue == value)
{
internalChange = true;
this.Value = value;
internalChange = false;
}
else
{
this.Value = value;
}
return(true);
}
public ValueChangedArgs(ValueChangeReason reason, int oldValue, int newValue)
{
this.Reason = reason;
this.oldValue = oldValue;
this.newValue = newValue;
}
public ValueChangingArgs(ValueChangeReason reason, int oldValue, int newValue)
: base(reason, oldValue, newValue)
{
}
