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[操作系统]android中实现监听的四种方法


(1)自身类作为事件监听器

package cn.edu.gdmec.s07150745.work5;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn1 = (Button) findViewById(R.id.btn1);
btn1.setText("单击");
btn1.setOnClickListener(this);
}

@Override
public void onClick(View v) {
Toast.makeText(this,"已单击我...",Toast.LENGTH_SHORT).show();
System.out.println("已单击我...");
}
}

 

(2)外部类作为事件监听器:

package cn.edu.gdmec.s07150745.work5;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class Act2 extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_act2);
Button btn2 = (Button) findViewById(R.id.btn2);
btn2.setText("单击");
btn2.setOnClickListener(new OuterClass("已单击我..."));
}
}
class OuterClass implements View.OnClickListener{
private String str="已单击我....";
public OuterClass(String str){
super();
this.str=str;
}
@Override
public void onClick(View v) {
System.out.println(str);
}
}

 

(3)内部类作为事件监听器:

package cn.edu.gdmec.s07150745.work5;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class Act3 extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_act3);
Button btn3 = (Button) findViewById(R.id.btn3);
btn3.setText("单击");
btn3.setOnClickListener(new OuterClass());
}
class OuterClass implements View.OnClickListener{

@Override
public void onClick(View v) {
Toast.makeText(Act3.this,"已单击我...",Toast.LENGTH_SHORT).show();
System.out.println("已单击我...");
}
}
}

 

(4)匿名类作为事件监听器:

package cn.edu.gdmec.s07150745.work5;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class Act4 extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_act4);
Button btn4 = (Button) findViewById(R.id.btn4);
btn4.setText("单击");
btn4.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(Act4.this,"已单击我...",Toast.LENGTH_SHORT).show();
System.out.println("已单击我...");
}
});
}
}

 

以上四种方法之后,在

<activity android:name=".MainActivity" android:label="1">
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>