Question

我正在开发一个应用程序，我尝试添加后退按钮，但工具栏不再显示在模拟器上。这是我的代码。

的Manifest.xml

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

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

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

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".HomeActivity"
        android:screenOrientation="portrait"
        android:theme="@style/Theme.AppCompat.NoActionBar" />
    <activity android:name=".VerificationActivity">
        <activity android:name=".MainActivity" />
    </activity>
    <activity android:name=".DashboardActivity" />
    <activity
        android:name=".LoginActivity"
        android:theme="@style/Theme.AppCompat.NoActionBar" />
    <activity android:name=".ProblemsActivity" />
    <activity
        android:name=".TotalActivity"
        android:theme="@style/Theme.AppCompat.NoActionBar" />
    <activity android:name=".FirstPayment" />
    <activity android:name=".FirstPaymentInformation" />
    <activity android:name=".DeclineQuestionsActivity" />
    <activity android:name=".LIkelyProblemsActivity" />
    <activity
        android:name=".TotalAmountActivity"
        android:theme="@style/Theme.AppCompat.NoActionBar" />
    <activity android:name=".ThanksActivity" />
    <activity
        android:name=".SignUpActivity"
        android:theme="@style/SignUpTheme" />
    <activity android:name=".StripePayment" />
    <activity
        android:name=".PaymentActivity"
        android:label="@string/title_activity_payment"
        android:theme="@style/AppTheme.NoActionBar" />
    <activity android:name=".LocationActivity" />
    <activity android:name=".SecondPayment" />
    <activity android:name=".DriverPayment"></activity><!-- ATTENTION: This was auto-generated to add Google Play services to your project for
 App Indexing.  See https://g.co/AppIndexing/AndroidStudio for more information. -->
    <meta-data
        android:name="com.google.android.gms.version"
        android:value="@integer/google_play_services_version" />
</application>

的style.css

<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>
    <item name="windowActionBar">true</item>
    <item name="windowNoTitle">true</item>
</style>

<style name="SplashTheme" parent="Theme.AppCompat.NoActionBar">
    <item name="android:windowBackground">@drawable/splash_screen</item>
</style>

<style name="SignUpTheme" parent="Theme.AppCompat.NoActionBar">
    <item name="android:textColorHint">#bdbdbd</item>
    <item name="android:windowBackground">@color/colorWhite</item>

</style>

<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

myActivity

public class DashboardActivity extends AppCompatActivity {

Toolbar toolbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_dashboard);

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

   if (getSupportActionBar() == null){
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setDisplayShowHomeEnabled(true);
    }

public void mechanicFN (View view){
    Intent intent = new Intent(DashboardActivity.this, LIkelyProblemsActivity.class); // Create an Intent
    startActivity(intent); // Move to Verification Activity
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();

    if (id == R.id.logout){

        SharedPreferences preferences = getSharedPreferences("Mypref", 0);
        preferences.edit().clear().commit();
        Intent intent = new Intent(DashboardActivity.this, HomeActivity.class); // Create an Intent
        startActivity(intent); // Move to Verification Activity

        Toast.makeText(getApplicationContext(), "Logout Selected", Toast.LENGTH_SHORT).show();
    }
    return super.onOptionsItemSelected(item);
}
}

R.layout.activity_dashboard

<?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:orientation="vertical"
    android:id="@+id/activity_dashboard"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:background="@color/colorBackground"
    tools:context="com.example.system2.tranxav.DashboardActivity">
    <LinearLayout
        android:layout_width="match_parent"
        android:orientation="horizontal"
        android:layout_marginTop="24dp"
        android:layout_height="wrap_content">
    <android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:id="@+id/cv"
        android:layout_marginRight="8dp"
        >
        <RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">
            <ImageView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:srcCompat="@drawable/mechanic"
                android:onClick="mechanicFN"
                android:id="@+id/imageView2" />
            <TextView
                android:text="Hire a Mechanic"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_below="@id/imageView2"
                android:gravity="center"
                android:layout_marginBottom="16dp"
                android:textColor="#000"
                android:id="@+id/textView2" />
        </RelativeLayout>

        </android.support.v7.widget.CardView>
    <android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_weight="1"
        android:layout_marginLeft="8dp"

        android:layout_height="wrap_content"
        android:id="@+id/cv1"
        >
    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_weight="1"
        android:layout_height="wrap_content">
        <ImageView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:srcCompat="@drawable/toyin_van"
            android:id="@+id/imageView3" />

        <TextView
            android:text="Toyin Van"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/imageView3"
            android:gravity="center"
            android:textColor="#000"
            android:layout_marginBottom="16dp"
            android:id="@+id/textView3" />
    </RelativeLayout>
    </android.support.v7.widget.CardView>
</LinearLayout>
<LinearLayout
    android:layout_width="match_parent"
    android:orientation="horizontal"
    android:layout_marginTop="24dp"
    android:layout_height="wrap_content">
    <android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:id="@+id/cv3"
        android:layout_marginRight="8dp"
        >
        <RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">
            <ImageView
                android:layout_marginTop="16dp"
                android:layout_marginBottom="16dp"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:srcCompat="@drawable/spareparts"
                android:onClick="mechanicFN"
                android:id="@+id/imageView4" />

            <TextView
                android:text="Spare Parts"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_below="@id/imageView4"
                android:gravity="center"
                android:layout_marginBottom="16dp"
                android:textColor="#000"
                android:id="@+id/textView4" />
        </RelativeLayout>

    </android.support.v7.widget.CardView>
    <android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_weight="1"
        android:layout_marginLeft="8dp"

        android:layout_height="wrap_content"
        android:id="@+id/cv5"
        >
        <RelativeLayout
            android:layout_width="wrap_content"
            android:layout_weight="1"
            android:layout_height="wrap_content">
            <ImageView
                android:layout_marginTop="16dp"
                android:layout_marginBottom="16dp"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:srcCompat="@drawable/electrician"
                android:id="@+id/imageView5" />

            <TextView
                android:text="Auto Electrician"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_below="@id/imageView5"
                android:gravity="center"
                android:textColor="#000"
                android:layout_marginBottom="16dp"
                android:id="@+id/textView5" />
        </RelativeLayout>
    </android.support.v7.widget.CardView>


</LinearLayout>

enter image description here 我浏览了代码，但我无法弄清楚问题出在哪里。我尝试删除活动上的工具栏，但它不起作用。

Answer 1

将主题添加到Activity。

<style name="AppThemeNoActionBar" parent="Theme.AppCompat.Light.NoActionBar">
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
 </style>

在Manifest

<activity
    android:name=".DashBoardActivity"
    android:label="@string/title_activity_payment"
    android:theme="@style/AppThemeNoActionBar" />

将onCreate()修改为。

if (getSupportActionBar() != null){
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setDisplayShowHomeEnabled(true);
}

工具栏显示在IDE中，但不显示在模拟器上

1 个答案: