Android应用程序图标未显示在操作栏上

Question

I am creating an android app using eclipse and I have a problem. the app icon doesn't show on actionbar. can anybody tell me what's wrong? here is the manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.gowemto.gnoulashe"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="16"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/Theme.AppCompat.Light" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".CalcResultActivity"
            android:label="@string/title_activity_calc_result"
            android:parentActivityName=".MainActivity" >
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.gowemto.gnoulashe.MainActivity" />
        </activity>

    </application>

</manifest>

and here's the main activity code:

package com.gowemto.gnoulashe;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;


public class MainActivity extends ActionBarActivity {
    String result;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    } 



    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return 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();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }



   public void intent1(View view) {  
         Intent intent = new Intent(this, CalcResultActivity.class);
            startActivity(intent);
    }



}

and here's the xml file of main activity:

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
<TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="16sp"
        android:text="@string/welcome_message" />  
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/add_the_dates"
        android:onClick="intent1"  />
</LinearLayout>

and this is what the actionbar look like when I run the app: http://i.imgur.com/jADDz7b.png

The app doesn't show any errors, and the icon is put in the right way in the directories. so can anyone tell me what's the problem and how can I fix it?

Answer 1

The problem with @ZsoltBoldizsár's answer is that you are using ActionBarActivity . Change getActionBar() to getSupportActionBar()

Add the following code in onCreate(Bundle) after you call super.onCreate(Bundle) :

getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setIcon(R.drawable.ic_launcher);

Appcompat-v7 automatically disables setDisplayShowHomeEnabled so you must set it to true to show an icon.

Answer 2

You need to configure the actionbar. Read the documentation , but the line below might help you.

getActionBar().setHomeButtonEnabled(true);
getActionBar().setIcon(here comes your drawable id)  (eg. R.drawable.ic_launcher)

Answer 3

Try with this:

ActionBar ab = getActionBar();
ab.setHomeButtonEnabled(true);
ab.setDisplayHomeAsUpEnabled(true);
ab.setDisplayShowTitleEnabled(false);
ab.setDisplayShowCustomEnabled(true);
ab.setTitle(Html.fromHtml("your text"));
ColorDrawable colorDrawable = new ColorDrawable(Color.parseColor(your_colorCode));
ab.show();