Android 程式开发：（十四）显示图像 —— 14.1 Gallery和ImageView

Gallery可以显示一系列的图片，并且可以横向滑动。下面展示如何使用Gallery去显示一系列的图片。

1. 创建一个工程，Gallery。

2. main.xml中的代码。

[html]
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Images of San Francisco" />

    <Gallery
        android:id="@+id/gallery1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <ImageView
        android:id="@+id/image1"
        android:layout_width="320dp"
        android:layout_height="250dp"
        android:scaleType="fitXY" />

</LinearLayout>
3. 在res/values文件夹下面新建一个文件，attrs.xml。
4. attrs.xml中的代码。

[html]
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="Gallery1">
        <attr name="android:galleryItemBackground" />
    </declare-styleable>
</resources>
5. 准备一些图片。将这些图片放在res/drawable-mdpi下面。

6. GalleryActivity.java中的代码。

[java]
public class GalleryActivity extends Activity {
    Integer[] imageIDs = {
            R.drawable.pic1,
            R.drawable.pic2,
            R.drawable.pic3,
            R.drawable.pic4,
            R.drawable.pic5,
            R.drawable.pic6,
            R.drawable.pic7
    };

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Gallery gallery = (Gallery) findViewById(R.id.gallery1);

        gallery.setAdapter(new ImageAdapter(this));
        gallery.setOnItemClickListener(new OnItemClickListener()
        {
            public void onItemClick(AdapterView<?> parent, View v,
            int position, long id)
            {
                Toast.makeText(getBaseContext(),
                        "pic" + (position + 1) + " selected",
                        Toast.LENGTH_SHORT).show();

                ImageView imageView = (ImageView) findViewById(R.id.image1);
                imageView.setImageResource(imageIDs[position]);
            }
        });
    }

    public class ImageAdapter extends BaseAdapter
    {
        Context context;
        int itemBackground;

        public ImageAdapter(Context c)
        {
            context = c;
            //---setting the style---
            TypedArray a = obtainStyledAttributes(R.styleable.Gallery1);

            itemBackground = a.getResourceId(
                R.styleable.Gallery1_android_galleryItemBackground, 0);

            a.recycle();
        }

        //---returns the number of images---
        public int getCount() {
            return imageIDs.length;
        }


        //---returns the item---
        public Object getItem(int position) {
            return position;
&nb

补充：移动开发 , Android ,