onclicklistener到底怎么用?

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转载地址:http://blog.csdn.net/dickren123/article/details/7216975

相信很多像我一样的新手学习ANDROID开发会遇到这个问题,通过这几天的归类和总结,将我的理解写在下面,欢迎大家一起前来讨论:

以按钮BUTTON的监听事件为例,以下的监听实现都是等价的:

1.使用接口继承按钮监听方法:

package dickren123.hui.say_hello_to_world;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.TextView;/* 这里接口继承的方法是隶属于按钮BUTTON的,因此前面导入的头文件只需有BUTTON即可*/public class Hello_to_worldActivity extends Activity implements Button.OnClickListener{/** Called when the activity is first created. */private Button btn_say_hello;private TextView hello_world;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);btn_say_hello = (Button)findViewById(R.id.bnt_SAY_HELLO_TO_WORLD);hello_world = (TextView)findViewById(R.id.textView1);btn_say_hello.setOnClickListener(this) ;//由于该类继承了BUTTON的监听,} //因此设置监听的参数只需传本类的对象即可public void onClick(View v) {// TODO Auto-generated method stubhello_world.setText("dickren123!");//抽象接口的内部方法的实现}}

2.使用接口继承view类的监听方法

package dickren123.hui.say_hello_to_world;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;/* 导入的头文件需要有view类监听*/import android.widget.Button;import android.widget.TextView;public class Hello_to_worldActivity extends Activity implements OnClickListener{    /** Called when the activity is first created. */private Button btn_say_hello;private TextView hello_world;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        btn_say_hello = (Button)findViewById(R.id.bnt_SAY_HELLO_TO_WORLD);        hello_world = (TextView)findViewById(R.id.textView1);        btn_say_hello.setOnClickListener(this) ;//由于该类继承了view的监听,    } //因此设置监听的参数只需传本类的对象即可public void onClick(View v) {// TODO Auto-generated method stubhello_world.setText("dickren123!");//抽象接口的内部方法的实现}}

3.不用接口,在类内部直接实现监听

package dickren123.hui.say_hello_to_world;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.TextView;public class Hello_to_worldActivity extends Activity {/** Called when the activity is first created. */private Button btn_say_hello;private TextView hello_world;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);btn_say_hello = (Button)findViewById(R.id.bnt_SAY_HELLO_TO_WORLD);hello_world = (TextView)findViewById(R.id.textView1);btn_say_hello.setOnClickListener(new Button.OnClickListener(){public void onClick(View v) { //使用匿名的Button实例// TODO Auto-generated method stubhello_world.setText("dickren123!");//抽象接口的内部方法的实现}}) ;} }

如果不使用匿名实例,也可以定义一个具体的实例,如下:

package dickren123.hui.say_hello_to_world;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.Button;public class Hello_to_worldActivity extends Activity {/** Called when the activity is first created. */private Button btn_say_hello;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);btn_say_hello = (Button)findViewById(R.id.bnt_SAY_HELLO_TO_WORLD);btn_listener bl = new btn_listener();btn_say_hello.setOnClickListener(bl); //bl是类btn_listener的实例,而btn_listener为监听方法的接口} //因此设置监听的参数只需传本类的对象即可}class btn_listener implements Button.OnClickListener{public void onClick(View v) {// TODO Auto-generated method stub}}

希望大家多多交流!^_^


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