当我尝试为 activity 设置工具栏时，设置了两个工具栏标题。需要一些关于删除其中一个的帮助
Two toolbar titles are set when I try to set the toolbar for an activity. Need some help regarding removing one of them
我试图使用 LiveData、ViewModel、Room 和 DataBinding 的 Android Jetpack 架构组件制作这个记事本应用程序。该应用程序包含三个 activity 布局、一个菜单布局、一个工具栏布局，我计划将其用于所有这些活动。此工具栏布局包含一个 textView，将用于使用 DataBinding 设置工具栏布局。
以下是重要的 XML 文件：
custom_notes_toolbar_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<data>
<variable
name="toolbarTitle"
type="String" />
</data>
<androidx.appcompat.widget.Toolbar
android:id="@+id/activity_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/color_primary">
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:fontFamily="@font/nunito_semibold"
android:text="@{toolbarTitle}"
android:textColor="@color/muted_white"
android:textSize="20sp" />
</androidx.appcompat.widget.Toolbar>
</layout>
activity_display_note.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:bind="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context=".view.DisplayNoteActivity">
<data>
<variable
name="toolbarTitle"
type="String" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="@+id/toolbar_linear_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<include
android:id="@+id/toolbar"
layout="@layout/custom_notes_toolbar_layout"
bind:toolbarTitle="@{toolbarTitle}" />
</com.google.android.material.appbar.AppBarLayout>
</LinearLayout>
<TextView
android:id="@+id/title_text_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fontFamily="@font/nunito"
android:padding="15dp"
android:textSize="25sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/toolbar_linear_layout" />
<TextView
android:id="@+id/content_text_view"
android:layout_width="match_parent"
android:layout_height="0dp"
android:fontFamily="@font/nunito_extralight"
android:gravity="start"
android:padding="15dp"
android:textSize="20sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/title_text_view" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/edit_note_floating_action_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="30sp"
android:layout_marginBottom="30sp"
android:contentDescription="@string/edit_note"
android:src="@drawable/ic_edit"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
display_note_menu.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="@+id/delete_menu_option"
android:icon="@drawable/ic_delete"
android:title="@string/delete_menu_string"
app:showAsAction="always" />
</menu>
DisplayNoteActivity.java
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.databinding.DataBindingUtil;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProvider;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;
import com.arpansircar.java.notepadapplicationusingmvvm.R;
import com.arpansircar.java.notepadapplicationusingmvvm.databinding.ActivityDisplayNoteBinding;
import com.arpansircar.java.notepadapplicationusingmvvm.model.Constants;
import com.arpansircar.java.notepadapplicationusingmvvm.room.NotesEntity;
import com.arpansircar.java.notepadapplicationusingmvvm.viewmodel.DisplayNoteActivityViewModel;
/**
* The DisplayNoteActivity displays the contents of a single note.
* Upon clicking a certain note in the NotesActivity RecyclerView, the user is guided to this activity and the selected note is displayed here.
* In this activity, the user can view, delete, or update the particular note as required.
* All such changes are reflected back in the NotesActivity.
*/
public class DisplayNoteActivity extends AppCompatActivity implements View.OnClickListener {
private ActivityDisplayNoteBinding activityDisplayNoteBinding;
private NotesEntity currentNoteEntity;
private DisplayNoteActivityViewModel displayNoteActivityViewModel;
/*The onCreate method is the first method to be executed when the application starts up.
* Here, those methods are called that are to be executed only once.
* This particular method executes the setToolbarMethod(), getIntentData(), and initializeViewModel() methods.
* The setToolbarMethod() sets the toolbar which contains the functionality for deleting a note.
* The getIntentData() fetches complete note details including the note id, title, content, and date.
* The initializeViewModel() method creates an instance of the AddEditNoteActivityViewModel class.*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
activityDisplayNoteBinding = DataBindingUtil.setContentView(this, R.layout.activity_display_note);
setToolbarMethod();
getIntentData();
initializeViewModel();
}
/*onStart() lifecycle callback method is executed after onCreate().
* In this callback method, two methods are executed.
* The setObserver() method activates the observer to check any changes arising within the LiveData object.
* The setOnClickListenerMethod() intercepts any clicks occurring within the activity.*/
@Override
protected void onStart() {
super.onStart();
startObserver();
setOnClickListenerMethod();
}
/*The onCreateOptionsMenu(...) creates the menu options in the toolbar.
* Here, a single menu option is used to delete the note being viewed.*/
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.display_note_menu, menu);
return true;
}
/*The onOptionsItemSelected(...) method intercepting the clicks occurring on the menu options.
* Here, a single menu option will be displayed to allow the user to delete the particular note being viewed.
* Upon being pressed, this delete option will trigger the deleteNoteMethod() and the activity will be removed from the view.*/
@Override
public boolean onOptionsItemSelected(@NonNull MenuItem item) {
int id = item.getItemId();
if (id == R.id.delete_menu_option) {
deleteNoteMethod();
finish();
return true;
} else {
return super.onOptionsItemSelected(item);
}
}
/*The setToolbarMethod() sets the custom toolbar in the activity.*/
private void setToolbarMethod() {
Toolbar toolbar = activityDisplayNoteBinding.toolbar.activityToolbar;
activityDisplayNoteBinding.setToolbarTitle(getString(R.string.display_activity_title));
setSupportActionBar(toolbar);
}
/*The initializeViewModel() creates an instance to the DisplayNoteActivityViewModel for communicating with the database.*/
private void initializeViewModel() {
displayNoteActivityViewModel = new ViewModelProvider(this).get(DisplayNoteActivityViewModel.class);
}
/*The setObserverMethod() method is used simply activates the observer.*/
private void startObserver() {
final Observer<NotesEntity> notesEntityObserver = notesEntity -> {
this.currentNoteEntity = notesEntity;
setNoteInActivity(notesEntity);
};
displayNoteActivityViewModel.selectNoteMethod(getIntentData()).observe(this, notesEntityObserver);
}
/*The setOnClickListenerMethod() method sets the onClickListener to the floating action button used in the activity.*/
private void setOnClickListenerMethod() {
activityDisplayNoteBinding.editNoteFloatingActionButton.setOnClickListener(this);
}
/*The setNoteInActivity(...) method sets the NotesEntity instance within the activity.
* The method is triggered by any changes occurring within the LiveData instance.
* A try-catch block is placed to handle the NullPointerExceptions that arise when a note is deleted.
* The NullPointerException occurs as the observer observes a change and tries to fetch the changed note.
* But this isn't possible as the note has already been deleted from the database, causing the exception.
* Therefore, the catch block handles the exception by removing the activity from view and showing a Toast message.*/
private void setNoteInActivity(NotesEntity notesEntity) {
try {
activityDisplayNoteBinding.titleTextView.setText(notesEntity.getTitle());
activityDisplayNoteBinding.contentTextView.setText(notesEntity.getContent());
} catch (NullPointerException nullPointerException) {
finish();
}
}
/*The getIntentData() method extracts the noteID from the intent.*/
private int getIntentData() {
Intent intent = getIntent();
return intent.getIntExtra(Constants.COLUMN_ID, -1);
}
/*The deleteNoteMethod() deletes a note from the database and the NotesActivity.
* The method is triggered by the onOptionsItemSelected() method when the user presses the delete menu option in the toolbar.*/
private void deleteNoteMethod() {
displayNoteActivityViewModel.deleteNoteMethod(currentNoteEntity);
Toast.makeText(this, "Note Deleted", Toast.LENGTH_SHORT).show();
}
/*The onClick(...) method intercepts all clicks performed in the current activity.
* When the floating action button is clicked, the "edit" function, note id, title, content, and date is bundled into the intent as extras.
* Finally, this data is sent into the AddEditNoteActivity and the activity is started.*/
@Override
public void onClick(View view) {
if (view == activityDisplayNoteBinding.editNoteFloatingActionButton) {
Intent editNoteIntent = new Intent(DisplayNoteActivity.this, AddEditNoteActivity.class);
editNoteIntent.putExtra("function", "edit");
editNoteIntent.putExtra(Constants.COLUMN_ID, currentNoteEntity.getId());
editNoteIntent.putExtra(Constants.COLUMN_NAME_TITLE, currentNoteEntity.getTitle());
editNoteIntent.putExtra(Constants.COLUMN_NAME_CONTENT, currentNoteEntity.getContent());
editNoteIntent.putExtra(Constants.COLUMN_NAME_DATE, currentNoteEntity.getDate());
startActivity(editNoteIntent);
}
}
}
现在，问题出现在setToolbarMethod():
private void setToolbarMethod() {
Toolbar toolbar = activityDisplayNoteBinding.toolbar.activityToolbar;
activityDisplayNoteBinding.setToolbarTitle(getString(R.string.display_activity_title));
setSupportActionBar(toolbar);
}
当我尝试这个方法时，它会导致设置两个工具栏标题，即应用程序的名称和我试图通过 DataBinding 设置的标题。
我试图完全删除 setToolbarMethod()，但这意味着我无法设置工具栏，实际上，我也无法设置菜单。我使用 DataBinding 设置工具栏标题而不是使用提供的 setTitle() 方法的原因是我希望标题文本的字体不同于此方法默认提供的字体。
我知道这个问题听起来有点令人困惑。如果需要，我可以根据需要提供详细信息。感谢您的帮助。
让我们来剖析一下：
<androidx.appcompat.widget.Toolbar
android:id="@+id/activity_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/color_primary">
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:fontFamily="@font/nunito_semibold"
android:text="@{toolbarTitle}"
android:textColor="@color/muted_white"
android:textSize="20sp" />
</androidx.appcompat.widget.Toolbar>
您在工具栏中放置了一个 TextView，但工具栏已经支持标题。删除这个textview，不要在textview上设置任何东西，想办法改变工具栏！
private void setToolbarMethod() {
Toolbar toolbar = activityDisplayNoteBinding.toolbar.activityToolbar;
setSupportActionBar(toolbar);
}
这将创建您的工具栏。
在您的 AndroidManifest.xml 中，您会看到类似这样的内容：
<activity
android:name=".foo"
android:label="some value" /> <-- you can change some value here to give the toolbar a default title.
或者，
<androidx.appcompat.widget.Toolbar
app:title="foo"
android:id="@+id/activity_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/color_primary">
各种不同的标题设置方式，你的问题基本上是工具栏里面无缘无故有一个TextView引起的
private void setNoteInActivity(NotesEntity notesEntity) {
try {
activityDisplayNoteBinding.titleTextView.setText(notesEntity.getTitle()); <-- this now becomes invalid, the text view is removed
activityDisplayNoteBinding.contentTextView.setText(notesEntity.getContent());
} catch (NullPointerException nullPointerException) { <-- side-note, this is terrible and probably not what you want to be doing, you should at least be printing the stack trace, calling finish will kill the entire activity without you or the user knowing what happened
finish();
}
}
你可以用getSupportActionBar().setTitle("My Title");代替
我试图使用 LiveData、ViewModel、Room 和 DataBinding 的 Android Jetpack 架构组件制作这个记事本应用程序。该应用程序包含三个 activity 布局、一个菜单布局、一个工具栏布局，我计划将其用于所有这些活动。此工具栏布局包含一个 textView，将用于使用 DataBinding 设置工具栏布局。
以下是重要的 XML 文件：
custom_notes_toolbar_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<data>
<variable
name="toolbarTitle"
type="String" />
</data>
<androidx.appcompat.widget.Toolbar
android:id="@+id/activity_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/color_primary">
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:fontFamily="@font/nunito_semibold"
android:text="@{toolbarTitle}"
android:textColor="@color/muted_white"
android:textSize="20sp" />
</androidx.appcompat.widget.Toolbar>
</layout>
activity_display_note.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:bind="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context=".view.DisplayNoteActivity">
<data>
<variable
name="toolbarTitle"
type="String" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="@+id/toolbar_linear_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<include
android:id="@+id/toolbar"
layout="@layout/custom_notes_toolbar_layout"
bind:toolbarTitle="@{toolbarTitle}" />
</com.google.android.material.appbar.AppBarLayout>
</LinearLayout>
<TextView
android:id="@+id/title_text_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fontFamily="@font/nunito"
android:padding="15dp"
android:textSize="25sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/toolbar_linear_layout" />
<TextView
android:id="@+id/content_text_view"
android:layout_width="match_parent"
android:layout_height="0dp"
android:fontFamily="@font/nunito_extralight"
android:gravity="start"
android:padding="15dp"
android:textSize="20sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/title_text_view" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/edit_note_floating_action_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="30sp"
android:layout_marginBottom="30sp"
android:contentDescription="@string/edit_note"
android:src="@drawable/ic_edit"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
display_note_menu.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="@+id/delete_menu_option"
android:icon="@drawable/ic_delete"
android:title="@string/delete_menu_string"
app:showAsAction="always" />
</menu>
DisplayNoteActivity.java
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.databinding.DataBindingUtil;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProvider;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;
import com.arpansircar.java.notepadapplicationusingmvvm.R;
import com.arpansircar.java.notepadapplicationusingmvvm.databinding.ActivityDisplayNoteBinding;
import com.arpansircar.java.notepadapplicationusingmvvm.model.Constants;
import com.arpansircar.java.notepadapplicationusingmvvm.room.NotesEntity;
import com.arpansircar.java.notepadapplicationusingmvvm.viewmodel.DisplayNoteActivityViewModel;
/**
* The DisplayNoteActivity displays the contents of a single note.
* Upon clicking a certain note in the NotesActivity RecyclerView, the user is guided to this activity and the selected note is displayed here.
* In this activity, the user can view, delete, or update the particular note as required.
* All such changes are reflected back in the NotesActivity.
*/
public class DisplayNoteActivity extends AppCompatActivity implements View.OnClickListener {
private ActivityDisplayNoteBinding activityDisplayNoteBinding;
private NotesEntity currentNoteEntity;
private DisplayNoteActivityViewModel displayNoteActivityViewModel;
/*The onCreate method is the first method to be executed when the application starts up.
* Here, those methods are called that are to be executed only once.
* This particular method executes the setToolbarMethod(), getIntentData(), and initializeViewModel() methods.
* The setToolbarMethod() sets the toolbar which contains the functionality for deleting a note.
* The getIntentData() fetches complete note details including the note id, title, content, and date.
* The initializeViewModel() method creates an instance of the AddEditNoteActivityViewModel class.*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
activityDisplayNoteBinding = DataBindingUtil.setContentView(this, R.layout.activity_display_note);
setToolbarMethod();
getIntentData();
initializeViewModel();
}
/*onStart() lifecycle callback method is executed after onCreate().
* In this callback method, two methods are executed.
* The setObserver() method activates the observer to check any changes arising within the LiveData object.
* The setOnClickListenerMethod() intercepts any clicks occurring within the activity.*/
@Override
protected void onStart() {
super.onStart();
startObserver();
setOnClickListenerMethod();
}
/*The onCreateOptionsMenu(...) creates the menu options in the toolbar.
* Here, a single menu option is used to delete the note being viewed.*/
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.display_note_menu, menu);
return true;
}
/*The onOptionsItemSelected(...) method intercepting the clicks occurring on the menu options.
* Here, a single menu option will be displayed to allow the user to delete the particular note being viewed.
* Upon being pressed, this delete option will trigger the deleteNoteMethod() and the activity will be removed from the view.*/
@Override
public boolean onOptionsItemSelected(@NonNull MenuItem item) {
int id = item.getItemId();
if (id == R.id.delete_menu_option) {
deleteNoteMethod();
finish();
return true;
} else {
return super.onOptionsItemSelected(item);
}
}
/*The setToolbarMethod() sets the custom toolbar in the activity.*/
private void setToolbarMethod() {
Toolbar toolbar = activityDisplayNoteBinding.toolbar.activityToolbar;
activityDisplayNoteBinding.setToolbarTitle(getString(R.string.display_activity_title));
setSupportActionBar(toolbar);
}
/*The initializeViewModel() creates an instance to the DisplayNoteActivityViewModel for communicating with the database.*/
private void initializeViewModel() {
displayNoteActivityViewModel = new ViewModelProvider(this).get(DisplayNoteActivityViewModel.class);
}
/*The setObserverMethod() method is used simply activates the observer.*/
private void startObserver() {
final Observer<NotesEntity> notesEntityObserver = notesEntity -> {
this.currentNoteEntity = notesEntity;
setNoteInActivity(notesEntity);
};
displayNoteActivityViewModel.selectNoteMethod(getIntentData()).observe(this, notesEntityObserver);
}
/*The setOnClickListenerMethod() method sets the onClickListener to the floating action button used in the activity.*/
private void setOnClickListenerMethod() {
activityDisplayNoteBinding.editNoteFloatingActionButton.setOnClickListener(this);
}
/*The setNoteInActivity(...) method sets the NotesEntity instance within the activity.
* The method is triggered by any changes occurring within the LiveData instance.
* A try-catch block is placed to handle the NullPointerExceptions that arise when a note is deleted.
* The NullPointerException occurs as the observer observes a change and tries to fetch the changed note.
* But this isn't possible as the note has already been deleted from the database, causing the exception.
* Therefore, the catch block handles the exception by removing the activity from view and showing a Toast message.*/
private void setNoteInActivity(NotesEntity notesEntity) {
try {
activityDisplayNoteBinding.titleTextView.setText(notesEntity.getTitle());
activityDisplayNoteBinding.contentTextView.setText(notesEntity.getContent());
} catch (NullPointerException nullPointerException) {
finish();
}
}
/*The getIntentData() method extracts the noteID from the intent.*/
private int getIntentData() {
Intent intent = getIntent();
return intent.getIntExtra(Constants.COLUMN_ID, -1);
}
/*The deleteNoteMethod() deletes a note from the database and the NotesActivity.
* The method is triggered by the onOptionsItemSelected() method when the user presses the delete menu option in the toolbar.*/
private void deleteNoteMethod() {
displayNoteActivityViewModel.deleteNoteMethod(currentNoteEntity);
Toast.makeText(this, "Note Deleted", Toast.LENGTH_SHORT).show();
}
/*The onClick(...) method intercepts all clicks performed in the current activity.
* When the floating action button is clicked, the "edit" function, note id, title, content, and date is bundled into the intent as extras.
* Finally, this data is sent into the AddEditNoteActivity and the activity is started.*/
@Override
public void onClick(View view) {
if (view == activityDisplayNoteBinding.editNoteFloatingActionButton) {
Intent editNoteIntent = new Intent(DisplayNoteActivity.this, AddEditNoteActivity.class);
editNoteIntent.putExtra("function", "edit");
editNoteIntent.putExtra(Constants.COLUMN_ID, currentNoteEntity.getId());
editNoteIntent.putExtra(Constants.COLUMN_NAME_TITLE, currentNoteEntity.getTitle());
editNoteIntent.putExtra(Constants.COLUMN_NAME_CONTENT, currentNoteEntity.getContent());
editNoteIntent.putExtra(Constants.COLUMN_NAME_DATE, currentNoteEntity.getDate());
startActivity(editNoteIntent);
}
}
}
现在，问题出现在setToolbarMethod():
private void setToolbarMethod() {
Toolbar toolbar = activityDisplayNoteBinding.toolbar.activityToolbar;
activityDisplayNoteBinding.setToolbarTitle(getString(R.string.display_activity_title));
setSupportActionBar(toolbar);
}
当我尝试这个方法时，它会导致设置两个工具栏标题，即应用程序的名称和我试图通过 DataBinding 设置的标题。
我试图完全删除 setToolbarMethod()，但这意味着我无法设置工具栏，实际上，我也无法设置菜单。我使用 DataBinding 设置工具栏标题而不是使用提供的 setTitle() 方法的原因是我希望标题文本的字体不同于此方法默认提供的字体。
我知道这个问题听起来有点令人困惑。如果需要，我可以根据需要提供详细信息。感谢您的帮助。
让我们来剖析一下：
<androidx.appcompat.widget.Toolbar
android:id="@+id/activity_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/color_primary">
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:fontFamily="@font/nunito_semibold"
android:text="@{toolbarTitle}"
android:textColor="@color/muted_white"
android:textSize="20sp" />
</androidx.appcompat.widget.Toolbar>
您在工具栏中放置了一个 TextView，但工具栏已经支持标题。删除这个textview，不要在textview上设置任何东西，想办法改变工具栏！
private void setToolbarMethod() {
Toolbar toolbar = activityDisplayNoteBinding.toolbar.activityToolbar;
setSupportActionBar(toolbar);
}
这将创建您的工具栏。
在您的 AndroidManifest.xml 中，您会看到类似这样的内容：
<activity
android:name=".foo"
android:label="some value" /> <-- you can change some value here to give the toolbar a default title.
或者，
<androidx.appcompat.widget.Toolbar
app:title="foo"
android:id="@+id/activity_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/color_primary">
各种不同的标题设置方式，你的问题基本上是工具栏里面无缘无故有一个TextView引起的
private void setNoteInActivity(NotesEntity notesEntity) {
try {
activityDisplayNoteBinding.titleTextView.setText(notesEntity.getTitle()); <-- this now becomes invalid, the text view is removed
activityDisplayNoteBinding.contentTextView.setText(notesEntity.getContent());
} catch (NullPointerException nullPointerException) { <-- side-note, this is terrible and probably not what you want to be doing, you should at least be printing the stack trace, calling finish will kill the entire activity without you or the user knowing what happened
finish();
}
}
你可以用getSupportActionBar().setTitle("My Title");代替