Why my app crashes on startup (Android Studio)

Question

I am developing an app on Android Studio IDE version 1.1.0. It is a percentage app...

My problem is when I start the app on a device it keeps crashing on startup.

Here is my AndroidManifest.xml

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

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <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>
</application>

MainActivity.java

package com.ziad_homework.myapplication;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;


public class MainActivity extends Activity {

TextView totalTextView;
EditText percentageTxt;
EditText numberTxt;

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

    totalTextView = (TextView) findViewById(R.id.totalTextView);
    percentageTxt = (EditText) findViewById(R.id.percentageTxt);
    numberTxt = (EditText) findViewById(R.id.numTxt);

    Button calcBtn = (Button) findViewById(R.id.calcBtn);
    calcBtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view)
        {
            float percentage = Float.parseFloat(percentageTxt.getText().toString());
            float dec = percentage / 100;
            float total = dec * Float.parseFloat(numberTxt.getText().toString());
            totalTextView.setText(Float.toString(total));
        }
    });
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.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();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="wrap_content"
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"     tools:context=".MainActivity">


<TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="0"
    android:id="@+id/totalTextView"
    android:layout_marginTop="29dp"
    android:textStyle="normal"
    android:layout_alignParentTop="true"
    android:layout_alignParentEnd="true"
    android:layout_alignParentStart="true"
    android:layout_alignParentBottom="false"
    android:layout_alignParentLeft="false"
    android:layout_alignWithParentIfMissing="false"
    android:layout_alignParentRight="false"
    android:autoText="false"
    android:elegantTextHeight="false"
    android:gravity="center"
    android:textAlignment="center"
    android:textSize="50dp" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="What is"
    android:id="@+id/textView"
    android:layout_below="@+id/totalTextView"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="35dp" />

<EditText
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:inputType="numberDecimal"
    android:ems="10"
    android:id="@+id/percentageTxt"
    android:layout_marginTop="28dp"
    android:hint="Enter Percentage"
    android:textAlignment="center"
    android:gravity="center"
    android:layout_below="@+id/textView"
    android:layout_centerHorizontal="true" />

<EditText
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:inputType="numberDecimal"
    android:ems="10"
    android:id="@+id/numTxt"
    android:hint="Enter Number"
    android:textAlignment="center"
    android:gravity="center"
    android:layout_marginTop="18dp"
    android:layout_below="@+id/textView3"
    android:layout_toStartOf="@+id/textView2" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="%"
    android:id="@+id/textView2"
    android:layout_alignBottom="@+id/percentageTxt"
    android:layout_alignEnd="@+id/totalTextView"
    android:layout_marginEnd="25dp"
    android:layout_marginRight="55dp"
    android:layout_marginBottom="5dp"
    android:textSize="30dp" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="of"
    android:id="@+id/textView3"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="CALCULATE"
    android:id="@+id/calcBtn"
    android:layout_marginTop="39dp"
    android:background="#e8443e6f"
    android:textColor="#ffffff"
    android:gravity="center"
    android:layout_below="@+id/numTxt"
    android:layout_alignStart="@+id/numTxt"
    android:layout_alignEnd="@+id/numTxt" />
</RelativeLayout>

strings.xml

<resources>
<string name="app_name">Percent Calculator</string>

<string name="hello_world">Hello world!</string>
<string name="action_settings">Settings</string>
</resources>

colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="primaryColor">#e8443e6f</color>
</resources>

styles.xml (v21)

<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="AppTheme" parent="android:Theme.Material.Light">
    <item name="android:colorPrimary">@color/primaryColor</item>
</style>

</resources>

the logcat:

     04-30 14:53:23.541  20522-20522/com.ziad_homework.myapplication E/Zygote﹕ MountEmulatedStorage()
    04-30 14:53:23.541  20522-20522/com.ziad_homework.myapplication E/Zygote﹕ v2
    04-30 14:53:23.541  20522-20522/com.ziad_homework.myapplication I/SELinux﹕ Function: selinux_compare_spd_ram , priority [2] , priority version is VE=SEPF_SM-J105F_5.1.1_0046
    04-30 14:53:23.541  20522-20522/com.ziad_homework.myapplication E/SELinux﹕ [DEBUG] get_category: variable seinfo: default sensitivity: NULL, cateogry: NULL
    04-30 14:53:23.541  20522-20522/com.ziad_homework.myapplication I/art﹕ Late-enabling -Xcheck:jni
    04-30 14:53:23.541  20522-20522/com.ziad_homework.myapplication E/art﹕ setrlimit(RLIMIT_CORE) failed for pid 20522: Operation not permitted
    04-30 14:53:23.541  20522-20522/com.ziad_homework.myapplication I/libpersona﹕ KNOX_SDCARD checking this for 10111
    04-30 14:53:23.541  20522-20522/com.ziad_homework.myapplication I/libpersona﹕ KNOX_SDCARD not a persona
    04-30 14:53:23.581  20522-20530/com.ziad_homework.myapplication E/art﹕ Failed sending reply to debugger: Broken pipe
    04-30 14:53:23.581  20522-20530/com.ziad_homework.myapplication I/art﹕ Debugger is no longer active
    04-30 14:53:23.611  20522-20522/com.ziad_homework.myapplication W/ResourcesManager﹕ getTopLevelResources: /data/app/com.ziad_homework.myapplication-2/base.apk / 1.0 running in com.ziad_homework.myapplication rsrc of package null
    04-30 14:53:23.641  20522-20522/com.ziad_homework.myapplication W/ResourcesManager﹕ getTopLevelResources: /data/app/com.ziad_homework.myapplication-2/base.apk / 1.0 running in com.ziad_homework.myapplication rsrc of package null
    04-30 14:53:23.651  20522-20522/com.ziad_homework.myapplication W/ResourcesManager﹕ getTopLevelResources: /data/app/com.ziad_homework.myapplication-2/base.apk / 1.0 running in com.ziad_homework.myapplication rsrc of package null
    04-30 14:53:23.661  20522-20522/com.ziad_homework.myapplication D/AndroidRuntime﹕ Shutting down VM
    04-30 14:53:23.661  20522-20522/com.ziad_homework.myapplication E/AndroidRuntime﹕ FATAL EXCEPTION: main
        Process: com.ziad_homework.myapplication, PID: 20522
        java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ziad_homework.myapplication/com.ziad_homework.myapplication.MainActivity}: java.lang.RuntimeException: A TaskDescription's primary color should be opaque
                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3150)
                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3260)
                at android.app.ActivityThread.access$1000(ActivityThread.java:218)
                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1734)
                at android.os.Handler.dispatchMessage(Handler.java:102)
                at android.os.Looper.loop(Looper.java:145)
                at android.app.ActivityThread.main(ActivityThread.java:6934)
                at java.lang.reflect.Method.invoke(Native Method)
                at java.lang.reflect.Method.invoke(Method.java:372)
                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)
         Caused by: java.lang.RuntimeException: A TaskDescription's primary color should be opaque
                at android.app.ActivityManager$TaskDescription.<init>(ActivityManager.java:592)
                at android.app.Activity.onApplyThemeResource(Activity.java:4050)
                at 
android.view.ContextThemeWrapper.initializeTheme(ContextThemeWrapper.java:140)
                at android.view.ContextThemeWrapper.setTheme(ContextThemeWrapper.java:85)
                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3096)
                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3260)
                at android.app.ActivityThread.access$1000(ActivityThread.java:218)
                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1734)
                at android.os.Handler.dispatchMessage(Handler.java:102)
                at android.os.Looper.loop(Looper.java:145)
                at android.app.ActivityThread.main(ActivityThread.java:6934)
                at java.lang.reflect.Method.invoke(Native Method)
                at java.lang.reflect.Method.invoke(Method.java:372)
                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)
    04-30 14:58:23.744  20522-20522/com.ziad_homework.myapplication I/Process﹕ Sending signal. PID: 20522 SIG: 9

Answer 1

You have chosen a translucent color (e8 for the alpha channel). That would be risky in general, as you do not know what color might be behind this, as it will vary by device. And, apparently Android itself does not like this, given your error message. Change that to ff, making the overall color ff443e6f, and see if that clears up your problem.