How to Increase the size of Image View in Android

问题:

I am working on a project that requires me to implement two horizontal scroll views with an image view in between them. I would like to extend the size of the image view to fill up the gap in between the scroll view. I went through the sample code, but it doesn't seem to mention anywhere in the size of the image view. I've enclosed the code below after the Image describing my problem.

public class Gallery2DemoActivity extends Activity {
private Gallery gallery,gallery1;
private ImageView imgView;

private Integer[] Imgid = {
    R.drawable.a_1, R.drawable.a_2, R.drawable.a_3, R.drawable.a_4, R.drawable.a_5, R.drawable.a_6, R.drawable.a_7
};

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

gallery = (Gallery) findViewById(R.id.examplegallery);
gallery.setAdapter(new AddImgAdp(this));

gallery1 = (Gallery)findViewById(R.id.examplegallery1);
gallery1.setAdapter(new AddImgAdp(this));

imgView = (ImageView)findViewById(R.id.ImageView01);    
imgView.setImageResource(Imgid[0]);


 gallery.setOnItemClickListener(new OnItemClickListener() {
    public void onItemClick(AdapterView parent, View v, int position, long id) {
        imgView.setImageResource(Imgid[position]); 
    }
});

}

public class AddImgAdp extends BaseAdapter {
int GalItemBg;
private Context cont;

public AddImgAdp(Context c) {
    cont = c;
    TypedArray typArray = obtainStyledAttributes(R.styleable.GalleryTheme);
    GalItemBg =  typArray.getResourceId(R.styleable.GalleryTheme_android_galleryItemBackground, 0);
    typArray.recycle();
}

public int getCount() {
    return Imgid.length;
}

public Object getItem(int position) {
    return position;
}

public long getItemId(int position) {
    return position;
}

public View getView(int position, View convertView, ViewGroup parent) {
    ImageView imgView = new ImageView(cont);

    imgView.setImageResource(Imgid[position]);
    imgView.setLayoutParams(new Gallery.LayoutParams(110, 100));
    imgView.setScaleType(ImageView.ScaleType.FIT_XY);
    imgView.setBackgroundResource(GalItemBg);

    return imgView;
}
}

This is my XML main file.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Gallery
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/examplegallery"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />
<ImageView
    android:id="@+id/ImageView01"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" 
    android:layout_weight="1"/>
<Gallery
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/examplegallery1"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />
</LinearLayout>

Below is my Attributes file:

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="GalleryTheme">
    <attr name="android:galleryItemBackground" />
</declare-styleable>
</resources>

回答1:

Vinner,

The issue here is really two issues:

1. The size of the ImageView is based on the parent, which means that it shares its width and height.

2. The Image is resized to match the most limiting dimension (width).

The easiest way to handle this is to set the ScaleType of the ImageView. There are a number of Scaling Types, but the one you probably want is Center Crop. In code, this is done by view_name.setScaleType(ImageView.ScaleType.CENTER_CROP). You may also do this in XML for your ImageView with the attribute android:scaleType="centerCrop". Mind you, this will resize your Image and maintain your aspect ratio, but it will cut off the sides.

Just add the above attribute to your ImageView in your XML, (probably under your layout_weight), and it should do what you want.

Hope this helps,

FuzzicalLogic

回答2:

will you try below code... ?

?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Gallery
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/examplegallery"
android:layout_width="fill_parent"
android:layout_height="wrap_content" android:layout_weight="1" />
<ImageView
android:id="@+id/ImageView01"
android:layout_width="fill_parent"
android:layout_height="0dp" 
android:src="@drawable/ic_launcher"
android:layout_weight="1"/>
<Gallery
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/examplegallery1"
android:layout_width="fill_parent"
android:layout_height="wrap_content" android:layout_weight="1"/>
</LinearLayout>

and if it do not work, try setting your gallery height to some dp, it will work.. Thanks

回答3:

The size of the ImageView is based on the parent, which means that it shares its width and height. Also, the Image is resized to match the most limiting dimension (width).

回答4:

It looks like in the AddImgAdp class, you set the ImageView's height and width to specific pixel sizes.

imgView.setLayoutParams(new Gallery.LayoutParams(110, 100)); //width = "110px", height="100px"

I personally would put the layout as a RelativeLayout, align the first gallery with the top, the second gallery with the bottom, nd have the ImageView set to align above the second gallery. Then make the image:

imgView.setLayoutParams( new Gallery.LayoutParams(
   Gallery.LayoutParams.FILL_PARENT, 
   Gallery.LayoutParams.FILL_PARENT) );

If you set the ImageView to fill_parent with a LinearLayout, it will fill to the bottom of the screen and the second gallery will be off the screen.

Also know that by filling in all the space you will most likely distort the picture. Consider all of your resizing options: http://developer.android.com/reference/android/widget/ImageView.ScaleType.html