返回鍵處理,back鍵功能類似home鍵
//返回鍵處理
Android 改寫返回鍵事件監聽,使得back鍵功能類似home鍵,讓Acitivty退至後臺時不被系統銷燬
現在很多程式要求back鍵不是退出程式而是像home鍵一樣讓Acitivty退至後臺時不被系統銷燬,查到的資料大多說都是繼承activity的沒有繼承TabActivity,
TabActivity和activity不能一樣處理,廢話不多說了上程式碼。
繼承activity的
/**
* 返回監聽
*/
public boolean onKeyDown(int keyCode, KeyEvent event) {
// TODO 監聽返回鍵,相當於點選home鍵
PackageManager pm = getPackageManager();
ResolveInfo homeInfo = pm.resolveActivity(
new Intent(Intent.ACTION_MAIN)
.addCategory(Intent.CATEGORY_HOME), 0);
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);
}
繼承TabActivity的
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
PackageManager pm = getPackageManager();
ResolveInfo homeInfo = pm.resolveActivity(
new Intent(Intent.ACTION_MAIN)
.addCategory(Intent.CATEGORY_HOME), 0);
if (event.getKeyCode() == KeyEvent.KEYCODE_BACK
&& event.getAction() == KeyEvent.ACTION_DOWN) {
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 false;
}
return super.dispatchKeyEvent(event);
}
private void startActivitySafely(Intent intent) {
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
try {
startActivity(intent);
} catch (ActivityNotFoundException e) {
Toast.makeText(this, "ActivityNotFoundExceptionnull",
Toast.LENGTH_SHORT).show();
} catch (SecurityException e) {
Toast.makeText(this, "SecurityExceptionnull", Toast.LENGTH_SHORT)
.show();
}
}