获取所有linearlayout子元素

Question

I have layout:

 <?xml version="1.0" encoding="utf-8"?> <ScrollView xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:fillViewport="true"> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:id="@+id/exchangeView"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="#fff000" android:gravity="center" android:text="Sticker 1" android:textColor="#372c24" android:textSize="20dp" /> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="bottom" android:layout_alignParentBottom="true" android:orientation="horizontal" android:id="@+id/next"> <Button android:id="@+id/btn_next" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1" android:layout_alignParentBottom="true" android:text="Next" /> </LinearLayout> </LinearLayout> </ScrollView> 

and related code:

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


    layout = (View) findViewById(R.id.exchangeView);
}

next thing I want to do is to get all children elements in this layout with Id=exchangeView , but when I type layout.getChildCount() android studio IDE compiler says:

Cannot resolve method 'getChildCount()'

However, if I put breakpoint on line where I assign layout a value, then if I evaluate expression I can execute method layout.getChildCount()

All I want to do is to execute layout.getChildCount() during runtime.

Thanks in advance!

Answer 1

You can try to use getChildCount() and also getChildAt() like this may be

int childcount = ll.getChildCount();
for (int i=0; i < childcount; i++){
  View v = ll.getChildAt(i);
}

Answer 2

Change this line

layout = (View) findViewById(R.id.exchangeView);

to

layout = (LinearLayout) findViewById(R.id.exchangeView);

I am assuming you have declared the variable layout as

View layout;

If so, change that to

LinearLayout layout;

The View class doesn't have the method getChildCount(), it is a method in the ViewGroup class. LinearLayout extends ViewGroup, and hence has access to it. View does not. This is related to polymorphism, which I suggest you look up. Cheers.

Answer 3

Try this:

LinearLayout layout = setupLayout();
int count = layout.getChildCount();
View v = null;
for(int i=0; i<count; i++) {
    v = layout.getChildAt(i);
    //do something with your child element
}