本文整理汇总了Java中android.app.Activity.onBackPressed方法的典型用法代码示例。如果您正苦于以下问题：Java Activity.onBackPressed方法的具体用法？Java Activity.onBackPressed怎么用？Java Activity.onBackPressed使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类android.app.Activity的用法示例。
在下文中一共展示了Activity.onBackPressed方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Java代码示例。
示例1: onBackPressed
import android.app.Activity; //导入方法依赖的package包/类
public void onBackPressed() {
Activity activity = getActivity();
if (activity != null) {
activity.onBackPressed();
}
}
示例2: navigateUpOrBack
import android.app.Activity; //导入方法依赖的package包/类
/**
* This utility method handles Up navigation intents by searching for a parent activity and
* navigating there if defined. When using this for an activity make sure to define both the
* native parentActivity as well as the AppCompat one when supporting API levels less than 16.
* when the activity has a single parent activity. If the activity doesn't have a single parent
* activity then don't define one and this method will use back button functionality. If "Up"
* functionality is still desired for activities without parents then use
* {@code syntheticParentActivity} to define one dynamically.
*
* Note: Up navigation intents are represented by a back arrow in the top left of the Toolbar
* in Material Design guidelines.
*
* @param currentActivity Activity in use when navigate Up action occurred.
* @param syntheticParentActivity Parent activity to use when one is not already configured.
*/
public static void navigateUpOrBack(Activity currentActivity,
Class<? extends Activity> syntheticParentActivity) {
// Retrieve parent activity from AndroidManifest.
Intent intent = NavUtils.getParentActivityIntent(currentActivity);
// Synthesize the parent activity when a natural one doesn't exist.
if (intent == null && syntheticParentActivity != null) {
try {
intent = NavUtils.getParentActivityIntent(currentActivity, syntheticParentActivity);
} catch (PackageManager.NameNotFoundException e) {
e.printStackTrace();
}
}
if (intent == null) {
// No parent defined in manifest. This indicates the activity may be used by
// in multiple flows throughout the app and doesn't have a strict parent. In
// this case the navigation up button should act in the same manner as the
// back button. This will result in users being forwarded back to other
// applications if currentActivity was invoked from another application.
currentActivity.onBackPressed();
} else {
if (NavUtils.shouldUpRecreateTask(currentActivity, intent)) {
// Need to synthesize a backstack since currentActivity was probably invoked by a
// different app. The preserves the "Up" functionality within the app according to
// the activity hierarchy defined in AndroidManifest.xml via parentActivity
// attributes.
TaskStackBuilder builder = TaskStackBuilder.create(currentActivity);
builder.addNextIntentWithParentStack(intent);
builder.startActivities();
} else {
// Navigate normally to the manifest defined "Up" activity.
NavUtils.navigateUpTo(currentActivity, intent);
}
}
}