Question

I have an ImageButton I just added in my layout, but when I call setContentView on the layout my program is now crashing. Looking at logcat, it seems to give me a NullPointerException when trying to create this ImageButton. ic_menu_send.png is in the appropriate drawable folders. Here’s the xml for the ImageButton:

<ImageButton
    android:id="@+id/imageButton1"
    android:src="@drawable/ic_menu_send"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@id/enterPassword2"
    android:layout_alignRight="@id/enterPassword1"
    android:layout_alignTop="@id/enterPassword2"
    android:background="@style/AppTheme"
    android:contentDescription="@string/submit_button" />

And here is the onCreate for this Activity:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.first_time); // causes nullpointerexception
    EditText enterPassword1 = (EditText)findViewById(R.id.enterPassword1);
    enterPassword1.setOnEditorActionListener(new TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            return onEditAction(v);
        }
    });
    EditText enterPassword2 = (EditText)findViewById(R.id.enterPassword2);
    enterPassword2.setOnEditorActionListener(new TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            return onEditAction(v);
        }
    });
    /*ImageButton submit1 = (ImageButton)findViewById(R.id.imageButton1);
    submit1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            EditText enterPassword1 = (EditText)findViewById(R.id.enterPassword1);
            onEditAction(enterPassword1);
        }
    });*/

The ImageButton part of the code was only commented out for testing, but the program crashes much earlier. Does anyone have an idea of what may be causing this? Thank you for your assistance.

Edit: Here are the logcat logs:

01-27 15:52:11.264: E/AndroidRuntime(31195): FATAL EXCEPTION: main
01-27 15:52:11.264: E/AndroidRuntime(31195): java.lang.RuntimeException: Unable to start activity ComponentInfo{us.securecow.nearfieldunlock/us.securecow.nearfieldunlock.FirstTimeActivity}: android.view.InflateException: Binary XML file line #50: Error inflating class android.widget.ImageButton
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.os.Handler.dispatchMessage(Handler.java:99)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.os.Looper.loop(Looper.java:137)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.app.ActivityThread.main(ActivityThread.java:5039)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at java.lang.reflect.Method.invokeNative(Native Method)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at java.lang.reflect.Method.invoke(Method.java:511)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at dalvik.system.NativeStart.main(Native Method)
01-27 15:52:11.264: E/AndroidRuntime(31195): Caused by: android.view.InflateException: Binary XML file line #50: Error inflating class android.widget.ImageButton
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.view.LayoutInflater.createView(LayoutInflater.java:613)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:56)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.view.LayoutInflater.onCreateView(LayoutInflater.java:660)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:685)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:270)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.app.Activity.setContentView(Activity.java:1881)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at us.securecow.nearfieldunlock.FirstTimeActivity.onCreate(FirstTimeActivity.java:19)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.app.Activity.performCreate(Activity.java:5104)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
01-27 15:52:11.264: E/AndroidRuntime(31195):    ... 11 more
01-27 15:52:11.264: E/AndroidRuntime(31195): Caused by: java.lang.reflect.InvocationTargetException
01-27 15:52:11.264: E/AndroidRuntime(31195):    at java.lang.reflect.Constructor.constructNative(Native Method)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at java.lang.reflect.Constructor.newInstance(Constructor.java:417)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.view.LayoutInflater.createView(LayoutInflater.java:587)
01-27 15:52:11.264: E/AndroidRuntime(31195):    ... 24 more
01-27 15:52:11.264: E/AndroidRuntime(31195): Caused by: android.content.res.Resources$NotFoundException: Resource is not a Drawable (color or path): TypedValue{t=0x1/d=0x7f050001 a=-1 r=0x7f050001}
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.content.res.Resources.loadDrawable(Resources.java:1927)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.content.res.TypedArray.getDrawable(TypedArray.java:601)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.view.View.<init>(View.java:3328)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.widget.ImageView.<init>(ImageView.java:114)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.widget.ImageButton.<init>(ImageButton.java:87)
01-27 15:52:11.264: E/AndroidRuntime(31195):    at android.widget.ImageButton.<init>(ImageButton.java:83)
01-27 15:52:11.264: E/AndroidRuntime(31195):    ... 27 more

Answer 1

Stack trace says it all:

Resource is not a Drawable (color or path):

According to the Android documentation, the background attribute needs either A drawable or a color.

Full quote:

A drawable to use as the background. This can be either a reference to
a full drawable resource (such as a PNG image, 9-patch, XML state list
description, etc), or a solid color such as “#ff000000” (black).

Style doesn’t fit any of those criteria, and so, your app crashes at runtime.