如何使菜单项单击事件调用方法 [英] how to make a menu item click event invoke a method

问题描述

大家好，



我正在构建一个桌面数据库应用程序。我希望菜单项的单击事件调用从数据库中获取数据的方法。以下是代码行：

Hello guys,

I am building a desktop database application. I want the menu items' click events to invoke methods that would fetch data from the the database. Here is the line of code:

//viewAllStaff.Click += new System.EventHandler(pdt.viewAllStaffMethod());

它提示我错误：方法名称预期。



请帮助。我是新手。

It prompt me that " error: method name expected".

Kindly help. I am a novice.

推荐答案

添加事件处理程序时，您需要提供方法名称，仅此而已。您的代码在方法名称后面有括号，就像您尝试调用该方法一样。将其更改为：

When adding the event handler, you are expected to supply a method name, nothing more. Your code has brackets after the method name, as if you are trying to call the method. Change it to:

viewAllStaff.Click += new System.EventHandler(pdt.viewAllStaffMethod);

编辑：

处理事件的方法不能只是任何旧方法。它需要遵循.NET的特定模式才能在事件发生时调用它。对于菜单项的单击事件，该模式为：

1.方法的返回类型必须为 void 。

2.该方法必须接受两个参数：对象名为 sender 和 EventArgs 名为 e 。



因此，方法声明必须是：

The method handling the event cannot be just any old method. It needs to follow a specific pattern for .NET to be able to call it when the event happens. In the case of a menu item's click event, that pattern is:
1. The method's return type must be void.
2. The method must accept two parameters: an object named sender and an EventArgs named e.

As such, the method declaration must be:

public void viewAllStaffMethod(object sender, EventArgs e)

这篇关于如何使菜单项单击事件调用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！