【安卓开发】点击事件的几种方法

NO.1
activityA.xml

android:layout_width=“wrap_content”
android:layout_height=“wrap_content”
android:text=“返回”
android:id="@+id/button"
android:layout_centerVertical=“true”
android:layout_centerHorizontal=“true”
android:onClick=“login”/>

activityA.java

public void login(View v){
//方法
}

NO.2
activityA.xml
android:layout_width=“wrap_content”
android:layout_height=“wrap_content”
android:text=“返回”
android:id="@+id/button"
android:layout_centerVertical=“true”
android:layout_centerHorizontal=“true” />**

activityA.java

public class MainActivity extends Activity{

    **Button button;**

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        **button = findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View view) {
                //方法
            }
        });**
    }

}

NO.3

activityA.xml

public class MainActivity extends Activity implements View.OnClickListener{
 **Button button;**
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
        }
	public void login(view  v){
		switch(v.getId()){
			case button:
				//方法
				break;
		}
	}
}