Android用一个易做图实现多个监听
在android应用程序中,有时要用到很多的按钮元件,没个按钮都要有一个监听事件,为了让代码看起来干净简洁,并节省一些内存,我们可以用一个易做图(Listener)来实现多个按钮的onClick监听下面是一个具有的例子:
[java] package com.android;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class IntentSelectActivity extends Activity implements View.OnClickListener{
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button1 = (Button)findViewById(R.id.btn1);
Button button2 = (Button)findViewById(R.id.btn2);
Button button3 = (Button)findViewById(R.id.btn3);
button1.setOnClickListener(this);
button1.setTag(1);
button2.setOnClickListener(this);
button2.setTag(2);
button3.setOnClickListener(this);
button3.setTag(3);
}
public void onClick(View v){
int tag = (Integer) v.getTag();
switch(tag){
case 1:
Intent music = new Intent(Intent.ACTION_GET_CONTENT);
music.setType("audio/*");
startActivity(Intent.createChooser(music, "Select music"));
break;
case 2:
Intent dial = new Intent();
dial.setAction("android.intent.action.CALL");
dial.setData(Uri.parse("tel:13428720000"));
startActivity(dial);
break;
case 3:
Intent wall易做图 = new Intent(Intent.ACTION_SET_WALLPAPER);
startActivity(Intent.createChooser(wall易做图, "Select Wall易做图"));
break;
default :
break;
}
}
}
package com.android;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class IntentSelectActivity extends Activity implements View.OnClickListener{
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button1 = (Button)findViewById(R.id.btn1);
Button button2 = (Button)findViewById(R.id.btn2);
Button button3 = (Button)findViewById(R.id.btn3);
button1.setOnClickListener(this);
button1.setTag(1);
button2.setOnClickListener(this);
button2.setTag(2);
button3.setOnClickListener(this);
button3.setTag(3);
}
public void onClick(View v){
int tag = (Integer) v.getTag();
switch(tag){
case 1:
Intent music = new Intent(Intent.ACTION_GET_CONTENT);
music.setType("audio/*");
startActivity(Intent.createChooser(music, "Select music"));
break;
case 2:
Intent dial = new Intent();
dial.setAction("android.intent.action.CALL");
dial.setData(Uri.parse("tel:13428720000"));
startActivity(dial);
break;
case 3:
Intent wall易做图 = new Intent(Intent.ACTION_SET_WALLPAPER);
startActivity(Intent.createChooser(wall易做图, "Select Wall易做图"));
break;
default :
break;
}
}
}
这段代码用三个按钮实现了三个Intent意图:音乐播放、自动拨号、背景选择。只用了一个onClick处理,这样代码看起来简洁了很多。
备注,Intent的属性写法与常数写法:
属性写法
Intent dial = new Intent();
dial.setAction("android.intent.action.CALL");
常数写法 www.zzzyk.com
Intent wall易做图 = new Intent(Intent.ACTION_SET_WALLPAPER);
Intent music = new Intent(Intent.ACTION_GET_CONTENT);
在Intent类中,定义了action的常数。在记忆技巧上,可以用 xxx对应到ACTION_xxx 的方式记。例如:
CALL(android.intent.action.CALL)就是ACTION_CALL(Intent.ACTION_CALL)。
程序运行效果为:
摘自 Young的专栏
补充:移动开发 , Android ,