Dynamic relative layout in android

问题

I am trying to have two images on tp of each other. I can have it work fine with an xml file but I would like to do this dynamically. ctdeasyone is a transparent image.

So this works fine..

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <ImageView 
        android:id="@+id/bck1" 
        android:src="@drawable/fish2"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"        
        android:scaleType="fitXY" 
        android:layout_gravity="center">
    </ImageView>

    <ImageView 
        android:id="@+id/bck2" 
        android:src="@drawable/ctdeasyone"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"        
        android:scaleType="fitXY" 
        android:layout_gravity="center">
    </ImageView>

</RelativeLayout>

When I do this. only the second image shows up (it is the transparent one.) Can any of the experts advice on this? Newbbie here... This is my first question. TIA.

public class TwoPicksOnEachOther extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Grabbing the Application context         
        final Context context = getApplication();                   

        RelativeLayout relativeLayout = new RelativeLayout(this);                   

        final ImageView iv = new ImageView(this);         
        iv.setImageResource(R.drawable.fish2);


        RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(     
                RelativeLayout.LayoutParams.FILL_PARENT, 
                RelativeLayout.LayoutParams.FILL_PARENT);
        relativeLayout.addView(iv,lp);        

        // Creating transparent image
        final ImageView iv2 = new ImageView(this);
        iv.setImageResource(R.drawable.ctdeasytwo);
        RelativeLayout.LayoutParams lp2 = new RelativeLayout.LayoutParams(     
                RelativeLayout.LayoutParams.FILL_PARENT, 
                RelativeLayout.LayoutParams.FILL_PARENT);
        relativeLayout.addView(iv2,lp2);
        setContentView(relativeLayout);

    }        

}

回答1:

I had to put it in the emulator and play with it for a while until I saw it:

iv.setImageResource(R.drawable.fish2);
(...)
iv.setImageResource(R.drawable.ctdeasytwo);

You're never setting the image resource for iv2!

I changed that and now I see two images as expected.

回答2:

This is perfect for FrameLayout . Since you want the images right on top of each other.

来源：https://stackoverflow.com/questions/5797076/dynamic-relative-layout-in-android

标签

android

layout

dynamic

relativelayout