How to send view to back ? How to control the z-order programmatically?

user_706780 0
Viewed 94066

I have a problem to send the view to back. In Android we have a method like bringToFront(), to place the view on top of the another view. Like that, I want to put the view on below the previous image.

Is there any method like sendToBack() or bringToBack() in Android. If so, can any one help me in this.

Note: that I do not want to control the z-order by the order of placing items in layout I want to control the z-order programmatically.

I do not want to hide the views on the front I just want them to be behind the view that is moving.

z-order android-layout view android
13 Answers

I realize that this has been implied in other answers, but no one posted the code. I keep the following in a utility class where I have "helper" functions for dealing with views:

public static void sendViewToBack(final View child) {
    final ViewGroup parent = (ViewGroup)child.getParent();
    if (null != parent) {
        parent.removeView(child);
        parent.addView(child, 0);
    }
}
user_14896390

it work's fine like bringToBack()

public void moveToBack(ViewGroup viewGroup, View v) {
    int s = 1;
    for (int i = 1; i < viewGroup.getChildCount(); i++) {
        if (viewGroup.getChildAt(1) == v) {
            s = 2;
        } else {
            viewGroup.getChildAt(s).bringToFront();
        }
    }
}
user_71954070

In your XML File you must to write in order:

<FrameLayout
android:id="@+id/frameLayoutXML"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
<ImageView
 android:id="@+id/imageViewXML"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/floatB_XML"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center" />
</FrameLayout>

In this case, the imageView will be back of the FloatingActionButton.

If you want change something, and you will do it programmatically then:

public class SomeActivity extends AppCompatActivity {

    //declare variables
    ImageView imageView;
    FrameLayout frameLayout;
    FloatingActionButton floatingActionButtonNew;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        //Here is to call what already exists at XML file
        frameLayout=findViewById(R.id.frameLayoutXML);   
        imageView = findViewById(R.id.imageViewXML);
        //Here is to declare a new Element to add to the view, but is not at XML File
        floatingActionButtonNew=New FloatingActionButton(this);
        frameLayout.removeAllViews();  //here you remove all views.
        frameLayout.addView(imageView);//And you add again the imageView first
        floatingActionButtonNew.setLayoutParams(new 
         RelativeLayout.LayoutParams(
          RelativeLayout.LayoutParams.WRAP_CONTENT,
          RelativeLayout.LayoutParams.WRAP_CONTENT
        )); //Then you can give some format to your floatingButtonNew

        //And finally  add to the frameLayout the new View in this case the floatingButtonNew
        frameLayout.addView(floatingActionButtonNew);
    }
}

In this order of view declarations, you will have again the image back from the floating button. So the view that is declared first will be back from the view that is declared secondly, and the key to achieve the order, is to removeAllViews of a FrameLayout or LinearLayout and add again this views when you are adding programmatically.

user_86974900

If the views in question are buttons, programmatic adjustments require a single line of xml for full z-order control. Otherwise, setElevation(), setZ(), setTranslationZ(), and bringToFront() will all inexplicably fail you. See description on separate thread below.

https://stackoverflow.com/a/68674834/14116101

user_141161010
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