Android 实现Activity后台运行

第一种方法

Java代码
Intent intent = new Intent(Intent.ACTION_MAIN);

intent.addCategory(Intent.CATEGORY_HOME);

intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

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。

Java代码

PackageManager pm = getPackageManager();

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

.addCategory(Intent.CATEGORY_HOME), 0);

Java代码

public boolean
onKeyDown(int keyCode, KeyEvent event) {

if (keyCode == KeyEvent.KEYCODE_BACK) {

ActivityInfo ai = homeInfo.activityInfo;

Intent startIntent = new Intent(Intent.ACTION_MAIN);

startIntent.addCategory(Intent.CATEGORY_LAUNCHER);

startIntent.setComponent(new ComponentName(ai.packageName,

ai.name));

startActivitySafely(startIntent);

return true;

} else

return super.onKeyDown(keyCode, event);

}


[b]Java代码

[/b]
[b]void
startActivitySafely(Intent intent) {

intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

try {

startActivity(intent);

} catch (ActivityNotFoundException e) {

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

Toast.LENGTH_SHORT).show();

} catch (SecurityException e) {

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

Toast.LENGTH_SHORT).show();

Log

.e(

TAG,

"Launcher does not have the permission to launch "

+ intent

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

+ "or use the exported attribute for this activity.",

e);

}

}

[/b]