在C#中引入参数提升方法 [英] Intilize parameter raise methods(On) in C#

问题描述

在此代码"e"中，哪里插入了vlulues，并在哪里传递了MesureItemEventArg?是否在上升时间内将其初始化?

in this code "e" where intilized and Where are vlalues and passed MesureItemEventArg ?Do it in the raise time, initilized?

protected override void OnMeasureItem(MeasureItemEventArgs e)
{

    base.OnMeasureItem(e);
    e.ItemHeight = 18;
}

推荐答案

是:引发事件时，您将MeasureItemEventArgs实例传递给事件.

Yes: when you raise the event, you will pass the MeasureItemEventArgs instance to the event.

protected override void OnMeasureItem(MeasureItemEventArgs e)
{
    //the property is modified BEFORE the event is fired.
    e.ItemHeight = 20;
    //fires the event
    base.OnMeasureItem(e);
    //here the property is modified AFTER the event is fired.
    //and will not be used anymore (this line of code is useless)
    e.ItemHeight = 18;
}
//event handler
private void control_MeasureItemEventHandler(Object sender, MeasureItemEventArgs e)
{
    //here height equals 20
    int height = e.ItemHeight;
    ...
}

这篇关于在C#中引入参数提升方法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！