Actionbar in Android Studio 1.4

Asked

Viewed 783 times

1

I upgraded my Android Studio to version 1.4 and am having problems implementing Actionbar in one activity. The application performs validation of a user’s data through the MainActivity and then directs the user to the second activity(WelcomeActivity). I’m trying to create a "up navigation "through the codegetActionBar().setDisplayHomeAsUpEnabled(true);but when I run the application, it closes at the moment it will go from one Activity to another. If I remove the information from the actionbar mentioned above, the application works normally. I have also tried to remove the information concerning toolbar that exists in the activities but did not work.

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

Mainactivity.java

package br.com.luizugliano.actionbar;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

}

public void onClickBtBuscar(View view){
    EditText etNome = (EditText) findViewById(R.id.etNome);
    EditText etCPF = (EditText) findViewById(R.id.etCPF);
    String nome = etNome.getText().toString();
    String cpf = etCPF.getText().toString();
    if("luiz".equals(nome) && "123456789".equals(cpf)){
        Intent intent = new Intent(getContext(),WelcomeActivity.class);
        Bundle params = new Bundle();
        params.putString("nome", "Luiz");
        intent.putExtras(params);
        startActivity(intent);
    }else{
        alert("Usuário não encontrado, faça seu cadastro");
    }
}

private Context getContext(){
    return this;
}

private void alert(String s){
    Toast.makeText(this, s, Toast.LENGTH_SHORT).show();
}
}

Welcomeactivity.java

package br.com.luizugliano.actionbar;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.MenuItem;
import android.widget.TextView;

public class WelcomeActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_welcome);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    Bundle args = getIntent().getExtras();
    String nome = args.getString("nome");

    //Atualizando o texto do TextView com uma mensagem de boas vindas
    TextView textView = (TextView) findViewById(R.id.textView);
    textView.setText(nome + ", seja bem-vindo.");

    //Adiciona o botão de navegação da action bar
    getActionBar().setDisplayHomeAsUpEnabled(true);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == android.R.id.home) {
        //O método finish encerrará essa activity
        finish();
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

Androidmanifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="br.com.luizugliano.actionbar" >

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".WelcomeActivity"
        android:label="@string/title_activity_welcome"
        android:theme="@style/AppTheme.NoActionBar"
        android:parentActivityName=".MainActivity">
    </activity>
</application>

content_welcome.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"
xmlns:app="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:showIn="@layout/activity_welcome"
tools:context="br.com.luizugliano.activity.WelcomeActivity">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:text="Medium Text"
    android:id="@+id/textView" />

activity_welcome.xml

<?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="br.com.luizugliano.actionbar.WelcomeActivity">

<android.support.design.widget.AppBarLayout android:layout_height="wrap_content"
    android:layout_width="match_parent" 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>

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

<!--<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>

Styles.xml

<resources>

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>
<style name="AppTheme.NoActionBar">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
</resources>

logcat crash log

10-15 00:25:42.457 4456-4456/br.com.luizugliano.actionbar W/System: Classloader referenced Unknown path: /data/app/br.com.luizugliano.actionbar-2/lib/x86 10-15 00:25:42.680 4456-4472/br.com.luizugliano.actionbar D/Openglrenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true 10-15 00:25:42.683 4456-4456/br.com.luizugliano.actionbar D/: Hostconnection::get() New Host Connection established 0xad70ddb0, tid 4456 10-15 00:25:42.735 4456-4472/br.com.luizugliano.actionbar D/: Hostconnection::get() New Host Connection established 0xad70dfb0, tid 4472 10-15 00:25:42.757 4456-4472/br.com.luizugliano.actionbar I/Openglrenderer: Initialized EGL, version 1.4 10-15 00:25:42.854 4456-4472/br.com.luizugliano.actionbar W/Egl_emulation: eglSurfaceAttrib not implemented 10-15 00:25:42.854 4456-4472/br.com.luizugliano.actionbar W/Openglrenderer: Failed to set EGL_SWAP_BEHAVIOR on Surface 0xabfa99e0, error=EGL_SUCCESS 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar D/Androidruntime: Shutting down VM 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: FATAL EXCEPTION: main 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: Process: br.com.luizugliano.actionbar, PID: 4456 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{br.com.luizugliano.actionbar/br.com.luizugliano.actionbar.WelcomeActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.Actionbar.setDisplayHomeAsUpEnabled(Boolean)' on a null Object Reference 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activitythread.performLaunchActivity(Activitythread.java:2416) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activitythread.handleLaunchActivity(Activitythread.java:2476) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activitythread. -wrap11(Activitythread.java) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activitythread$H.handleMessage(Activitythread.java:1344) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.os.Handler.dispatchMessage(Handler.java:102) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.os.Looper.loop(Looper.java:148) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activitythread.main(Activitythread.java:5417) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at java.lang.reflect.Method.invoke(Native Method) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at com.android.Internal.os.Zygoteinit$Methodandargscaller.run(Zygoteinit.java:726) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at com.android.Internal.os.Zygoteinit.main(Zygoteinit.java:616) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: Caused by: java.lang.Nullpointerexception: Attempt to invoke virtual method void 'android.app.Actionbar.setDisplayHomeAsUpEnabled(Boolean)' on a null Object Reference 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/AndroidRuntime: at br.com.luizugliano.actionbar.WelcomeActivity.onCreate(WelcomeActivity.java:25) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activity.performCreate(Activity.java:6237) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activitythread.performLaunchActivity(Activitythread.java:2369) 10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activitythread.handleLaunchActivity(Activitythread.java:2476)  10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activitythread. -wrap11(Activitythread.java)  10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activitythread$H.handleMessage(Activitythread.java:1344)  10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.os.Handler.dispatchMessage(Handler.java:102)  10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.os.Looper.loop(Looper.java:148)  10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at android.app.Activitythread.main(Activitythread.java:5417)  10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at java.lang.reflect.Method.invoke(Native Method)  10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at com.android.Internal.os.Zygoteinit$Methodandargscaller.run(Zygoteinit.java:726)  10-15 00:26:02.266 4456-4456/br.com.luizugliano.actionbar E/Androidruntime: at com.android.Internal.os.Zygoteinit.main(Zygoteinit.java:616) 

android android-studio actionbar

3 answers

2


The right one in this case, using the AppCompatActivity is to use the method getSupportActionBar.

If you did not use the support library, you could normally use the getActionBar

  • Thanks for the help. I was seeing the reason for the exception through logcat and is saying that my actionBar is null-br.com.luizugliano.actionbar.WelcomeActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference 10-15. I tried to remove the library AppCompactActivity extending another class I created to control the app’s lifecycle, but it’s still making a mistake when switching from one Active to another. Can you help me by showing how your suggestion would look in my codig

  • Exactly, you set the supportActionBar and is using the ActionBar normal. I believe it’s not the same.

  • Good! I tried to change the code with the suggestions you gave initially but still giving problem. You could send me your suggestion according to the code I posted?

  • Luiz, I made the suggestion already looking at your xD code but could update the question with the changes and the new error stacktrace?

  • Actually I changed the call from the class support library. I changed from public class WelcomeActivity extends AppCompatActivity { for public class WelcomeActivity extends LifeCycleActivity {, which is my other class that just treats the stages of the life cycle. Also, I removed the conditions below relating to toolbar - Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);&#xA; setSupportActionBar(toolbar);. The error returned was the same. I found strange the Manifest have updated my class with the information android:theme="@style/AppTheme.NoActionBar". =[

  • But in case, you still need to call getSupportActionBar, passing the Toolbar, because when using the theme with suffix NoActionBar, you are required to set up your Toolbar as ActionBar if you wanted to use it. Otherwise I believe you are correct. You are calling the setSupportActionBar in the superclass before the get?

  • Let’s go continue this discussion in chat.

Show 2 more comments

2

If someone still has this problem that is very common, there are several ways to use "Actionbar". I’ll tell you one way.

  1. For those who use the most current Android Studio: Open the Androidmanifest.xml file

You will have something similar to the code below:

<activity android:name=".MainActivity" android:label="@string/app_name" android:theme="@style/AppTheme.NoActionBar"

Remove the line android:Theme="@style/Apptheme.Noactionbar".

  1. If you have created an Activity by Wizard and it created the Toolbar, according to the code below:

    protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
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();
    }
});

    }

Remove these lines.

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

setSupportActionBar(Toolbar);

Floatingactionbutton Fab = (Floatingactionbutton) findViewById(R.id.Fab);

Fab.setOnClickListener(new View.Onclicklistener()

  1. Make this import, if possible manual.

import android.support.v7.app.ActionBar;

  1. Use the Actionbars as follows

ActionBar actionBar = getSupportActionBar();

This way your Actionbar will work, but it is worth remembering that (I honestly don’t know all, but most of) Actionbar class functions are obsleta.

I hope I helped. I’m new to Android programming. I had these problems too. Each time I did it in a different way and it worked, but that way I went up it seemed more certain. Hugs.

0

Problem solved by changing getActionBar().setDisplayHomeAsUpEnabled(true); for getSupportActionBar().setDisplayHomeAsUpEnabled(true);

Browser other questions tagged android android-studio actionbar

You are not signed in. Login or sign up in order to post.