2-10 four ways for Android buttons to listen to events (3)

1. There are four methods to set the listener for buttion in Android:

Directly implement the onclicklistener method for the activity, and then override its onclick method.

Use an internal class to create a class to implement the onclicklistener method.

Use a listener

Using anonymous internal classes is the most common method, but it is better to use the first method if there are many listening events. That is faster!

2. A very small problem to be aware of when alertdialog is defined

When instantiating alertdialog. Builder = new alertdialog. Builder (this); pay attention to the parameters in the brackets.

If it is instantiated in an anonymous internal class, you must add. This to the project file name! 10 million

Do not use the getapplicationcontext () method, because what is obtained!