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;@Overrideprotected 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{@Overridepublic 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 {@Overrideprotected 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();}}

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