Android——按钮的事件监听

关于Button按钮的四种事件监听方法总结

首先我们在activity_main.xml里面先定义一个Button空间

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="Button" />

</RelativeLayout>

好，现在要我们来看点击事件的四种写法：

1.最常见的一种写法——匿名的内部类做为事件监听器类

package com.basillee.blogdemo;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {

    private Button btnButton;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btnButton=(Button)findViewById(R.id.button1);
        btnButton.setOnClickListener(new OnClickListener() {
            public void onClick(View arg0) {
                Toast.makeText(MainActivity.this, "button clicked", Toast.LENGTH_LONG).show();
            }
        });
    }

}

2.内部类做为监听器

package com.basillee.blogdemo;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {

	private Button btnButton;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		btnButton=(Button)findViewById(R.id.button1);
		MyClicked myClicked=new MyClicked();
		btnButton.setOnClickListener(myClicked);
	}
	private class MyClicked implements OnClickListener{

		@Override
		public void onClick(View arg0) {
			Toast.makeText(getApplicationContext(), "Button clicked!", Toast.LENGTH_LONG).show();
		}

	}
}

3.Activity直接实现OnClickListener接口

package com.basillee.blogdemo;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener{

private Button btnButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnButton=(Button)findViewById(R.id.button1);
btnButton.setOnClickListener(this);
}
@Override
public void onClick(View arg0) {
Toast.makeText(this, "Button clicked!", Toast.LENGTH_LONG).show();
}

}

4.在布局文件中，用android：onClick属性指定对应的方法名实现

activity_main.xml代码如下：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="Button"
        android:onClick="myClick"/>

</RelativeLayout>

MainActivity.java代码如下：

package com.basillee.blogdemo;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
	}
	public void myClick(View v){
		Toast.makeText(getApplicationContext(),"Button clicked!", Toast.LENGTH_LONG).show();
	}
}