我正在尝试向我的 android-app 添加一个设置 fragment 。 所以,我添加了一个 xml 文件和这个 Activity :
public class SettingsActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Display the fragment as the main content.
getFragmentManager().beginTransaction()
.replace(android.R.id.content, new SettingsFragment())
.commit();
}
public static class SettingsFragment extends PreferenceFragment {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Load the preferences from an XML resource
addPreferencesFromResource(R.xml.preferences);
}
}
}
它是从主 Activity 中的 onOptionsItemSelected 函数调用的:
if (id == R.id.action_settings) {
Intent intent = new Intent(this, SettingsActivity.class);
startActivity(intent);
return true;
}
所以,现在,当我尝试从菜单中打开 Activity 时,它强制关闭并且我在控制台中收到此错误:
Force-removing child win Window{4190a9a8 u0 PopupWindow:418fc208} from container Window{418dd448 u0 org.name.app/org.name.app.MainActivity}
Failed looking up window
java.lang.IllegalArgumentException: Requested window android.os.BinderProxy@423b1fc0 does not exist
at com.android.server.wm.WindowManagerService.windowForClientLocked(WindowManagerService.java:7934)
at com.android.server.wm.WindowManagerService.windowForClientLocked(WindowManagerService.java:7925)
at com.android.server.wm.WindowState$DeathRecipient.binderDied(WindowState.java:1047)
at android.os.BinderProxy.sendDeathNotice(Binder.java:493)
at dalvik.system.NativeStart.run(Native Method)
最佳答案
您正在替换以前从未添加过的 fragment ......
getFragmentManager().beginTransaction()
.replace(android.R.id.content, new SettingsFragment())
.commit();
尝试
.add(android.R.id.content, new SettingsFragment())
但是正确的代码应该是(伪代码)
- 通过 id 或标签查找 fragment
- 如果找到的 fragment 为空,则创建一个。
您可以在网络和 stackoverflow 上找到大量示例。 ;)
更新 好的,这里有一些示例代码供您用作起点。
假设:您对多个 fragment 使用相同的 Activity ,因此您需要恢复现有的或创建一个新的。
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
Fragment newFragment = fm.findFragmentByTag("Some_Tag");
if (newFragment == null) {
newFragment = SomeFragment.newInstance(); //create a new frag
}
// Find the old one to know if we have to replace or simply add to this container
Fragment oldFragment = fm.findFragmentById(R.id.content_container);
if (oldFragment != null) {
ft.replace(R.id.content_container, newFragment, "Some_Tag");
} else {
ft.add(R.id.content_container, newFragment, "Some_Tag");
}
// optionally use a nice transition
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
// …and to the backstack if you wish…
ft.addToBackStack(null).commit();
另一方面,如果您只想要没有任何花哨的简单版本……
FragmentManager fm = getSupportFragmentManager();//if using support lib
Fragment fragment = fm.findFragmentById(R.id.your_container);
if (fragment == null) {
fragment = YourFragment.newInstance();
fm.beginTransaction()
.add(R.id.your_container, fragment, "some_tag_if_you_wish_to_use_find_by_tag_later")
.commit();
}
如果容器没有 fragment ,这只会添加 fragment 。否则没有什么可以做的,因为容器已经有了你的 fragment 。 :)
关于java - 安卓设置 fragment ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20749009/