Android 实现 Activity 后台运行

addison_lin

第一种方法
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1	Intent intent = new Intent(Intent.ACTION_MAIN);

2	intent.addCategory(Intent.CATEGORY_HOME);

3	intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

4	startActivity(intent);

第二种方法
此方法其实不是主要是屏蔽Keycode_Back，让它不结束（finish()）Activity，直接显示HOME界面。
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1	PackageManager pm = getPackageManager();

2	ResolveInfo homeInfo = pm.resolveActivity(new Intent(Intent.ACTION_MAIN)

3	.addCategory(Intent.CATEGORY_HOME), 0);

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01	public boolean onKeyDown(int keyCode, KeyEvent event) {

02	if (keyCode == KeyEvent.KEYCODE_BACK) {

03	ActivityInfo ai = homeInfo.activityInfo;

04	Intent startIntent = new Intent(Intent.ACTION_MAIN);

05	startIntent.addCategory(Intent.CATEGORY_LAUNCHER);

06	startIntent.setComponent(new ComponentName(ai.packageName,

07	ai.name));

08	startActivitySafely(startIntent);

09	return true;

10

} else

11	return super.onKeyDown(keyCode, event);

12

}

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01	void startActivitySafely(Intent intent) {

02	intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

03

try {

04	startActivity(intent);

05	} catch (ActivityNotFoundException e) {

06	Toast.makeText(this, R.string.unabletoopensoftware,

07	Toast.LENGTH_SHORT).show();

08	} catch (SecurityException e) {

09	Toast.makeText(this, R.string.unabletoopensoftware,

10	Toast.LENGTH_SHORT).show();

11

Log

12

.e(

13

TAG,

14	”Launcher does not have the permission to launch ”

15

+ intent

16	+ ”. Make sure to create a MAIN intent-filter for the corresponding activity ”

17	+ ”or use the exported attribute for this activity.”,

18

e);

19

}

20

}