如何在工具栏的右侧放置活动的标题 [英] How to put the title of the Activity on the right of the toolbar

问题描述

我已经编写了一个代码来将活动的标题向右移动.以下是Java代码.我正在使用getSupportActionBar().

这是

I have written a code to shift the title of the activity to right.The following is the java code.I am using getSupportActionBar().

Here's the Image of the toolbar I want

   package com.example.hsports.practicesession;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.TextView;

public class HomePage extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_home_page);

        String getUserEmail = getIntent().getExtras().getString("userEmail");
        String getUserPassword = getIntent().getExtras().getString("userPassword");


        TextView displayUserEmail= (TextView) findViewById(R.id.displayUserEmail);
        //this.setTitle("Welcome"+" "+getUserEmail);

       // getActionBar().setTitle("Welcome"+" "+getUserEmail);




        TextView displayUserPassword=(TextView)findViewById(R.id.displayUserPassword);


        displayUserEmail.setText(getUserEmail);
        displayUserPassword.setText(getUserPassword);







        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        TextView welcomeTextView = (TextView) toolbar.findViewById(R.id.welcomeText);
        welcomeTextView.setText("Welcome " + getUserEmail);


        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
    }

}

And this is the xml code which is for the Homepage.

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"

    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.example.hsports.practicesession.HomePage"
    tools:showIn="@layout/activity_home_page"

    >

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay"

        >

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay"

            />


        <RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">
            <TextView
                android:id="@+id/welcomeText"
                android:layout_marginRight="30dp"
                android:layout_alignParentRight="true"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />
        </RelativeLayout>

    </android.support.design.widget.AppBarLayout>



    <TextView
        android:id="@+id/displayUserEmail"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/displayUserPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />


</LinearLayout>

I actually want the title of the page to come to right of the above action bar. how to to do this.

The error I am getting is this:

07-14 00:03:03.763 3038-3038/com.example.hsports.practicesession E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.hsports.practicesession, PID: 3038 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.hsports.practicesession/com.example.hsports.practicesession.HomePage}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) at android.app.ActivityThread.-wrap11(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference at com.example.hsports.practicesession.HomePage.onCreate(HomePage.java:46) at android.app.Activity.performCreate(Activity.java:6237) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)  at android.app.ActivityThread.-wrap11(ActivityThread.java)  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)  at android.os.Handler.dispatchMessage(Handler.java:102)  at android.os.Looper.loop(Looper.java:148)  at android.app.ActivityThread.main(ActivityThread.java:5417)  at java.lang.reflect.Method.invoke(Native Method)  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 

解决方案

You should have a toolbar in your xml layout, so your xml file should look like this :

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:layout_gravity="right"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.example.hsports.practicesession.HomePage"
    tools:showIn="@layout/activity_home_page">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <TextView
        android:id="@+id/displayUserEmail"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/displayUserPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />


</LinearLayout>

and then you need to set the supportActionBar in the onCreate method like this :

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);

after this you can set the title :

getSupportActionBar().setTitle("Welcome"+" "+getUserEmail);

but in your case you're trying to set the title before you've set the supportActionBar, so you're getting NullPointerException.

Also, R.id.toolbar is not in your current xml layout, so again it'll throw a NullPointerException, so change your xml file to add a Toolbar as suggested above.

UPDATE

To have the text on right :

You need to add your own TextView inside the Toolbar and then there's no need to set toolbar title like this :

getSupportActionBar().setTitle("Welcome"+" "+getUserEmail);

Change your activity_home_page.xml code to this :

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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"
    android:fitsSystemWindows="true"
    tools:context="com.example.hsports.practicesession.HomePage">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" >
            <RelativeLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content">
                <TextView
                    android:id="@+id/welcomeText"
                    android:layout_marginRight="30dp"
                    android:layout_alignParentRight="true"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </RelativeLayout>

        </android.support.v7.widget.Toolbar>

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_home_page" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_margin="@dimen/fab_margin"
        android:src="@android:drawable/ic_dialog_email" />

</android.support.design.widget.CoordinatorLayout>

then in your Activity do this :

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
TextView welcomeTextView = (TextView) toolbar.findViewById(R.id.welcomeText);
welcomeTextView.setText("Welcome " + getUserEmail);

OUTPUT :

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