Android Studio 在片段中打开抽屉 [英] Android Studio open Drawer in fragment
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问题描述
我从应用程序中删除了操作栏，所以我需要创建按钮来自己打开抽屉 Activity 上的按钮工作正常但是当我在片段应用程序中使用它时停止工作(当我调用片段时)
I remove the actionbar from application so I need to create button to open drawer myself button on Activity works fine but when I'm using it in fragment application stop working (when I call the fragment)
我在 Activity 中使用的代码(运行良好的代码)
ImageButton btn = (ImageButton)findViewById(R.id.drawerButton);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.openDrawer(Gravity.START);
}
});
fragment_achievements.xml
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="layout.AchievementsFragment">
<ImageButton
android:id="@+id/imageButton"
android:layout_width="28dp"
android:layout_height="29dp"
android:layout_marginLeft="16dp"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:background="@android:color/transparent"
android:scaleType="fitCenter"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="@drawable/ic_menu_button" />
<WebView
android:id="@+id/web_ach"
android:layout_width="409dp"
android:layout_height="602dp"
android:layout_marginBottom="-9dp"
android:layout_marginLeft="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
tools:layout_editor_absoluteY="56dp" />
</android.support.constraint.ConstraintLayout>
AchievementsFragment.java
package layout;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.DrawerLayout;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ImageButton;
import th.ac.sd.sdschoolnd.R;
/**
* A simple {@link Fragment} subclass.
*/
public class AchievementsFragment extends Fragment {
public AchievementsFragment() {
// Required empty public constructor
}
public WebView mWebView;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
//return inflater.inflate(R.layout.fragment_achievements, container, false);
// Inflate the layout for this fragment
//return inflater.inflate(R.layout.fragment_snews, container, false);
View v=inflater.inflate(R.layout.fragment_achievements, container, false);
mWebView = (WebView) v.findViewById(R.id.web_ach);
mWebView.loadUrl("http://www.sd.ac.th/main/wp-content/WebApps/android/rss_achievements.html");
WebSettings webSettings = mWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
// Force links and redirects to open in the WebView instead of in a browser
mWebView.setWebViewClient(new WebViewClient());
ImageButton button = (ImageButton) getView().findViewById(R.id.drawerButton);
button.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
DrawerLayout drawer = (DrawerLayout) getView().findViewById(R.id.drawer_layout);
drawer.openDrawer(Gravity.START);
}
});
return v;
}
}
错误日志
[ 03-10 16:27:00.791 22121:22160 D/ ]
HostConnection::get() New Host Connection established 0x947f8c00, tid 22160
03-10 16:27:00.794 22121-22161/th.ac.sd.sdschoolnd E/chromium: [ERROR:gles2_cmd_decoder.cc(2210)] [GroupMarkerNotSet(crbug.com/242999)!:546A05A2]GL ERROR :GL_INVALID_OPERATION : BackFramebuffer::Create: <- error from previous GL command
03-10 16:27:00.798 22121-22160/th.ac.sd.sdschoolnd W/OpenGLRenderer: Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without...
03-10 16:27:00.798 22121-22160/th.ac.sd.sdschoolnd D/OpenGLRenderer: Swap behavior 0
03-10 16:27:00.857 22121-22121/th.ac.sd.sdschoolnd W/art: Attempt to remove non-JNI local reference, dumping thread
03-10 16:27:00.950 22121-22121/th.ac.sd.sdschoolnd W/art: Attempt to remove non-JNI local reference, dumping thread
03-10 16:27:00.984 22121-22121/th.ac.sd.sdschoolnd W/cr_BindingManager: Cannot call determinedVisibility() - never saw a connection for the pid: 22121
03-10 16:27:03.877 22121-22121/th.ac.sd.sdschoolnd W/art: Attempt to remove non-JNI local reference, dumping thread
03-10 16:27:03.895 22121-22121/th.ac.sd.sdschoolnd W/cr_AwContents: onDetachedFromWindow called when already detached. Ignoring
03-10 16:27:03.897 22121-22121/th.ac.sd.sdschoolnd I/cr_Ime: ImeThread is not enabled.
03-10 16:27:03.902 22121-22161/th.ac.sd.sdschoolnd E/chromium: [ERROR:gles2_cmd_decoder.cc(2210)] [GroupMarkerNotSet(crbug.com/242999)!:546F05A2]GL ERROR :GL_INVALID_OPERATION : BackFramebuffer::Create: <- error from previous GL command
03-10 16:27:03.902 22121-22121/th.ac.sd.sdschoolnd D/AndroidRuntime: Shutting down VM
03-10 16:27:03.902 22121-22121/th.ac.sd.sdschoolnd E/AndroidRuntime: FATAL EXCEPTION: main
Process: th.ac.sd.sdschoolnd, PID: 22121
java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference
at layout.AchievementsFragment.onCreateView(AchievementsFragment.java:44)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2189)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1299)
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1528)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1595)
at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:757)
at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2355)
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2146)
at android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps(FragmentManager.java:2098)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2008)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:710)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
推荐答案
那是因为你试图在 fragment 中找到 drawerLayout 而不是在 fragment 中但在您的 activity 中.
这是你的错误-DrawerLayout drawer = (DrawerLayout) getView().findViewById(R.id.drawer_layout);
而是在您的活动中创建方法并从您的 fragment 调用该方法
That is because you are trying to find drawerLayout in fragment which is not in fragment but in your activity.
This is your mistake -
DrawerLayout drawer = (DrawerLayout) getView().findViewById(R.id.drawer_layout);
Instead create method in your activity and call that method from your fragment
这将是 YourActivity 中的方法
public void openDrawer() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.openDrawer(Gravity.START);
}
现在从你的片段中调用这个方法 -
Now call this method from your fragment -
((YourActivity) getActivity()).openDrawer();
最后，您在片段中的代码将是:-
Finally, your code in fragment will be:-
button.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v) {
((YourActivity) getActivity()).openDrawer();
}
});
这篇关于Android Studio 在片段中打开抽屉的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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