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Android Build a Simple Android App (2014) Basic Android Programming Initializing a Button

Posted by Tasokwa Namalueso
Tasokwa Namalueso
283 Points

why am i getting a compiler error

its failing to compile

FunFactsActivity.java 
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class FunFactsActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fun_facts);

        // Declare our View variables and assign them the Views from the layout file
        TextView factLable= (TextView) findViewById(R.id.factTextview);
        Button showFactButton;

    }
}
Nitin George Cherian
Nitin George Cherian
4,410 Points
Nitin George Cherian
Nitin George Cherian
4,410 Points

Could you please post the compiler error as well as the activity_fun_facts.xml file ?

Tasokwa Namalueso
Tasokwa Namalueso
283 Points

<RelativeLayout 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: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=".FunFacts" android:id="@+id/showFactButton" android:background="#51b46d">

<TextView android:text="Did you know?" android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="24sp"
    android:textColor="#80ffffff" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Ants stretch when the wake up in the morning"
    android:id="@+id/factTextView"
    android:layout_centerVertical="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:textSize="25sp"
    android:textColor="@android:color/white" />

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Show Another Fun Fact"
    android:id="@+id/showFactButton"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:background="@android:color/white" />

</RelativeLayout>

/*09-23 15:00:30.467 32093-32093/biz.appfarm.funfacts E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: biz.appfarm.funfacts, PID: 32093 java.lang.RuntimeException: Unable to start activity ComponentInfo{biz.appfarm.funfacts/biz.appfarm.funfacts.FunFacts}: java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.Button at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233) at android.app.ActivityThread.access$800(ActivityThread.java:135) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5001) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.Button at biz.appfarm.funfacts.FunFacts.onCreate(FunFacts.java:21) at android.app.Activity.performCreate(Activity.java:5231) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)             at android.app.ActivityThread.access$800(ActivityThread.java:135)             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)             at android.os.Handler.dispatchMessage(Handler.java:102)             at android.os.Looper.loop(Looper.java:136)             at android.app.ActivityThread.main(ActivityThread.java:5001)             at java.lang.reflect.Method.invokeNative(Native Method) */

1 Answer

Peter Price
Peter Price
4,007 Points
Peter Price
Peter Price
4,007 Points

Hi Tasokwa,

I think the problem is this line of code:

TextView factLable= (TextView) findViewById(R.id.factTextview);

If you didn't use auto complete follow the below.

factTextview should be: factTextView, I think (capital V for view). And factLable should be: factLabel, I think ("el" not "le" for label) 

TextView factLable= (TextView) findViewById(R.id.factTextview);

Fire back if this doesn't work (or help).