我一直在尝试在我的应用程序中动态替换片段，但是这样做时我一直收到RuntimeException，因为它无法找到它应该添加片段的容器ID。我尝试过在类似线程上找到的每一个解决方案，从干净的构建到使用ChildFragmentManager，但我仍然有同样的错误。 最奇怪的是，当我在onCreate中指定没有容器时，一切都很顺利但是只要指定了容器，应用程序就会崩溃。这是代码和堆栈跟踪：
堆栈追踪：
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.user.onceuponatime, PID: 23668
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.user.onceuponatime/com.example.user.onceuponatime.activity.AuthentificationActivity}: java.lang.IllegalArgumentException: No view found for id 0x7f0d007f (com.example.user.onceuponatime:id/fragment_container) for fragment SignInFragment{42d6c688 #0 id=0x7f0d007f signinfragment}
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2394)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2452)
at android.app.ActivityThread.access$900(ActivityThread.java:172)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1302)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5586)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalArgumentException: No view found for id 0x7f0d007f (com.example.user.onceuponatime:id/fragment_container) for fragment SignInFragment{42d6c688 #0 id=0x7f0d007f signinfragment}
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1293)
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.FragmentController.execPendingActions(FragmentController.java:388)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:607)
at android.support.v7.app.AppCompatActivity.onStart(AppCompatActivity.java:178)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1177)
at android.app.Activity.performStart(Activity.java:5461)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2367)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2452)
at android.app.ActivityThread.access$900(ActivityThread.java:172)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1302)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5586)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
at dalvik.system.NativeStart.main(Native Method)
AuthentificationActivity：
public class AuthentificationActivity extends AppCompatActivity implements SignInFragment.SignInFragmentCallBack
,SignUpFragment.SignUpFragmentCallBack{
public static final String SIGNINFRAGMENT_TAG = "signinfragment";
public static final String SIGNUPFRAGMENT_TAG = "signupfragment";
public static final int SIGNIN_FRAGMENT_ID = 846464;
public static final int SIGNUP_FRAGMENT_ID = 125478;
public static final int LOST_PWD_FRAGMENT_ID = 85546;
private FragmentManager mFragmentManager;
private SignInFragment mSignInFragment;
private SignUpFragment mSignUpFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_authentification);
mSignInFragment = SignInFragment.getInstance();
mFragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();
fragmentTransaction.add(R.id.fragment_container,mSignInFragment,SIGNINFRAGMENT_TAG);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
@Override
public void onFragmentSwapRequested(int FragmentId) {
mFragmentManager = this.getSupportFragmentManager();
FragmentTransaction fgTransaction = mFragmentManager.beginTransaction();
switch(FragmentId) {
case SIGNUP_FRAGMENT_ID:
if(!isFinishing()) {
mSignUpFragment = (SignUpFragment) mFragmentManager.findFragmentByTag(SIGNUPFRAGMENT_TAG);
if (mSignUpFragment == null) {
mSignUpFragment = SignUpFragment.getInstance();
fgTransaction.replace(R.id.fragment_container, mSignUpFragment, SIGNUPFRAGMENT_TAG);
} else {
fgTransaction.show(mSignUpFragment);
}
fgTransaction.addToBackStack(null);
fgTransaction.commit();
}
break;
case LOST_PWD_FRAGMENT_ID:
break;
}
}
}
SignInFragment：
public class SignInFragment extends Fragment {
FragmentSignInBinding signInBinding;
private CoordinatorLayout mCoordinatorLayout;
private EditText mEmailEdit,mPasswordEdit;
private Button btnSignIn,btnSignUp,btnLostPwd;
private ProgressBar mProgressBar;
private FirebaseAuth mAuth;
private SignInFragmentCallBack mCallBack;
public interface SignInFragmentCallBack {
void onFragmentSwapRequested(int FragmentId);
}
public SignInFragment() {}
public static SignInFragment getInstance() {
return new SignInFragment();
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
try {
mCallBack = (SignInFragmentCallBack) context;
} catch(ClassCastException e) {
throw new ClassCastException(context.toString() + " must implements SignInCallaback");
}
Toast.makeText(context,mCallBack.toString(),Toast.LENGTH_LONG).show();
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
signInBinding = DataBindingUtil.setContentView(getActivity(),R.layout.fragment_sign_in);
mEmailEdit = signInBinding.emailSignin;
mPasswordEdit = signInBinding.passwordSignin;
mProgressBar = signInBinding.progressBarSignIn;
btnSignIn = signInBinding.signInButton;
btnSignUp = signInBinding.signUpButton;
btnLostPwd = signInBinding.passwordReset;
mCoordinatorLayout = signInBinding.coordinatorSignin;
mAuth = FirebaseAuth.getInstance();
btnSignIn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
signInAction();
}
});
btnSignUp.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(mCallBack instanceof SignInFragmentCallBack)
mCallBack.onFragmentSwapRequested(AuthentificationActivity.SIGNUP_FRAGMENT_ID);
}
});
btnLostPwd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(mCallBack instanceof SignInFragmentCallBack)
mCallBack.onFragmentSwapRequested(AuthentificationActivity.LOST_PWD_FRAGMENT_ID);
}
});
}
private void signInAction() {
String email = mEmailEdit.getText().toString().trim();
final String password = mPasswordEdit.getText().toString().trim();
if(TextUtils.isEmpty(email)) {
Snackbar.make(mCoordinatorLayout,getString(R.string.no_email_entered),Snackbar.LENGTH_LONG).show();
return;
}
if(TextUtils.isEmpty(password)) {
Snackbar.make(mCoordinatorLayout,getString(R.string.no_password_entered),Snackbar.LENGTH_LONG).show();
return;
}
mProgressBar.setVisibility(View.VISIBLE);
mAuth.signInWithEmailAndPassword(email,password).addOnCompleteListener(getActivity(), new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
mProgressBar.setVisibility(View.GONE);
if(task.isSuccessful()) {
Snackbar.make(mCoordinatorLayout,getString(R.string.login_success),Snackbar.LENGTH_LONG).show();
startActivity(new Intent(getActivity(), MainActivity.class));
getActivity().finish();
}
else
{
Snackbar.make(mCoordinatorLayout,getString(R.string.login_failed),Snackbar.LENGTH_LONG).show();
}
}
});
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_sign_in,container,false);
}
@Override
public void onResume() {
super.onResume();
mProgressBar.setVisibility(View.GONE);
}
}
activity_authentification.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_authentification"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.user.onceuponatime.activity.AuthentificationActivity">
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/fragment_container"/>
</LinearLayout>
编辑：我尝试检查R.java以查看Id是否搞砸了，但似乎一切都很好，其中fragment_container id显然存在。还尝试清理项目，但正如我所料，这并没有改变任何东西。我尝试用replace（）替换add，但仍然是相同的错误，除非我使用android.R.id.container作为容器。我正在使用数据绑定，也许这是冲突的原因？
EDIT2：我创建了一个新项目，在那里我做了相同的事务但是有一个简单的片段显示一个简单的TextView，一切似乎工作正常，看不到崩溃。所以我尝试删除我的片段中的模糊项目，例如回调，但我仍然遇到同样的错误。 DataBinding似乎不是问题，因为我试过没有它，仍然得到相同的堆栈跟踪。
感谢您的帮助。
答案 0 :(得分：1)
您的代码中的问题是您尝试将signInFragment UI绑定到onCreate方法中的行为，但此方法在onCreateView之前调用，如您所见fragment lifecycle。
如果您在onCreate中移动onCreateView方法的内容，或之后调用的任何方法，则不会再发生此类崩溃。