coderaizer coderaizer - 6 months ago 21
Android Question

ViewGroup is not resolved in Android Studio

I'm creating a small animation app using Android studio. When a button press images should work according to the particular animation.

There's an error with line viewGroup=(viewGroup)findViewById(R.id.ViewGroup);

It shows "Cannot resolve symbol 'ViewGroup'". I typed Alt+Enter and selected a solution. But nothing happened.

public class MainActivity extends Activity {
private ViewGroup viewGroup;
private ImageView imageView, imageView2, imageView3,imageView4,imageView5,imageView6,imageView7,imageView8,imageView9,imageView10,imageView11,imageView12;
private Button button,button1;

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

viewGroup=(viewGroup)findViewById(R.id.ViewGroup);

imageView= (ImageView) findViewById(R.id.imageView);
imageView2= (ImageView) findViewById(R.id.imageView2);
imageView3= (ImageView) findViewById(R.id.imageView3);
imageView4= (ImageView) findViewById(R.id.imageView4);
imageView5= (ImageView) findViewById(R.id.imageView5);
imageView6=(ImageView) findViewById(R.id.imageView6);
imageView7=(ImageView) findViewById(R.id.imageView7);
imageView8=(ImageView) findViewById(R.id.imageView8);
imageView9=(ImageView) findViewById(R.id.imageView9);
imageView10=(ImageView) findViewById(R.id.imageView10);
imageView11=(ImageView) findViewById(R.id.imageView11);
imageView12=(ImageView) findViewById(R.id.imageView12);



button = (Button)findViewById(R.id.button);
button1=(Button)findViewById(R.id.button1);


button1.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
TransitionManager.beginDelayedTransition(viewGroup, new Fade());
fade(imageView, imageView2, imageView3,imageView4,imageView5,imageView6);
}

});

button.setOnClickListener(new View.OnClickListener(){
public void onClick(View v) {
TransitionManager.beginDelayedTransition(viewGroup, new Slide());
toggle(imageView7,imageView8,imageView9,imageView10,imageView11,imageView12);
}
});}



private static void toggle(View... views) {
for (View v : views) {
boolean isVisible = v.getVisibility() == View.VISIBLE;
v.setVisibility(isVisible ? View.INVISIBLE :
View.VISIBLE);
}
}

private static void fade(View... views) {
for (View v : views) {
boolean isVisible = v.getVisibility() == View.VISIBLE;
v.setVisibility(isVisible ? View.INVISIBLE :
View.VISIBLE);
}


Here's my activity_main xml

<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=".MainActivity"
android:id="@+id/myAniLayout">

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Button"
android:id="@+id/button"
android:layout_alignParentBottom="true"
android:layout_alignParentStart="true"
android:layout_marginBottom="44dp" />

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Button"
android:id="@+id/button1"
android:layout_alignBottom="@+id/button"
android:layout_alignParentEnd="true" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:src="@mipmap/ic_launcher" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView2"
android:src="@mipmap/ic_launcher"
android:layout_below="@+id/imageView"
android:layout_alignParentStart="true" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView3"
android:src="@mipmap/ic_launcher"
android:layout_alignTop="@+id/imageView2"
android:layout_alignParentEnd="true" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView4"
android:src="@mipmap/ic_launcher"
android:layout_below="@+id/imageView2"
android:layout_centerHorizontal="true" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView5"
android:src="@mipmap/ic_launcher"
android:layout_below="@+id/imageView4"
android:layout_alignParentStart="true" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView6"
android:src="@mipmap/ic_launcher"
android:layout_below="@+id/imageView4"
android:layout_alignParentEnd="true" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView7"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"
android:src="@android:drawable/star_big_on" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView8"
android:src="@android:drawable/star_big_on"
android:layout_below="@+id/imageView7"
android:layout_alignParentStart="true" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView9"
android:src="@android:drawable/star_big_on"
android:layout_below="@+id/imageView7"
android:layout_alignParentEnd="true" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView10"
android:src="@android:drawable/star_big_on"
android:layout_below="@+id/imageView9"
android:layout_alignStart="@+id/button1" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView11"
android:src="@android:drawable/star_big_on"
android:layout_below="@+id/imageView8"
android:layout_alignEnd="@+id/button" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView12"
android:src="@android:drawable/star_big_on"
android:layout_above="@+id/button"
android:layout_alignStart="@+id/imageView4" />



Answer

Your logcat shows

"Cannot resolve symbol 'ViewGroup'"

 viewGroup=(viewGroup)findViewById(R.id.ViewGroup); // (ViewGroup)
  1. viewGroup Not declare in your XML

  2. (viewGroup) must be (ViewGroup) . (viewGroup)

The ViewGroup class is a subclass of the View class. ViewGroup instances work as containers for View instances to group View instances together.

http://developer.android.com/intl/es/reference/android/view/ViewGroup.html