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:
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package dickren123.hui.say_hello_to_world;
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import android.app.Activity;
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import android.os.Bundle;
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import android.view.View;
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import android.widget.Button;
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import android.widget.TextView;
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public class Hello_to_worldActivity extends Activity implements Button.OnClickListener{
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private Button btn_say_hello;
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private TextView hello_world;
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@Override
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public void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.main);
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btn_say_hello = (Button)findViewById(R.id.bnt_SAY_HELLO_TO_WORLD);
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hello_world = (TextView)findViewById(R.id.textView1);
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btn_say_hello.setOnClickListener(this) ;
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}
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public void onClick(View v) {
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hello_world.setText("dickren123!");
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}
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}
2.使用接口继承view类的监听方法
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package dickren123.hui.say_hello_to_world;
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import android.app.Activity;
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import android.os.Bundle;
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import android.view.View;
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import android.view.View.OnClickListener;
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import android.widget.Button;
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import android.widget.TextView;
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public class Hello_to_worldActivity extends Activity implements OnClickListener{
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private Button btn_say_hello;
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private TextView hello_world;
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@Override
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public void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.main);
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btn_say_hello = (Button)findViewById(R.id.bnt_SAY_HELLO_TO_WORLD);
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hello_world = (TextView)findViewById(R.id.textView1);
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btn_say_hello.setOnClickListener(this) ;
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}
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public void onClick(View v) {
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hello_world.setText("dickren123!");
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}
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}
3.不用接口,在类内部直接实现监听
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package dickren123.hui.say_hello_to_world;
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import android.app.Activity;
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import android.os.Bundle;
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import android.view.View;
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import android.widget.Button;
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import android.widget.TextView;
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public class Hello_to_worldActivity extends Activity {
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private Button btn_say_hello;
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private TextView hello_world;
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@Override
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public void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.main);
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btn_say_hello = (Button)findViewById(R.id.bnt_SAY_HELLO_TO_WORLD);
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hello_world = (TextView)findViewById(R.id.textView1);
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btn_say_hello.setOnClickListener(new Button.OnClickListener(){
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public void onClick(View v) {
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hello_world.setText("dickren123!");
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}
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}) ;
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}
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}
如果不使用匿名实例,也可以定义一个具体的实例,如下:
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package dickren123.hui.say_hello_to_world;
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import android.app.Activity;
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import android.os.Bundle;
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import android.view.View;
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import android.widget.Button;
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public class Hello_to_worldActivity extends Activity {
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private Button btn_say_hello;
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@Override
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public void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.main);
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btn_say_hello = (Button)findViewById(R.id.bnt_SAY_HELLO_TO_WORLD);
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btn_listener bl = new btn_listener();
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btn_say_hello.setOnClickListener(bl);
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}
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}
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class btn_listener implements Button.OnClickListener
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{
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public void onClick(View v) {
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}
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}
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