Android中Gallery和ImageSwitcher的使用

<ImageSwitcher
    android:id="@+id/imageSwitcher"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_weight="2"
    android:paddingTop="30px" >
</ImageSwitcher>

<Gallery
    android:id="@+id/gallery1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:spacing="5px"
    android:unselectedAlpha="0.6" />

</RelativeLayout></pre>

MainActivity.java代碼如下：

import android.app.ActionBar.LayoutParams;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity {

private int imageId[] = new int[] { R.drawable.a, R.drawable.b,
        R.drawable.c, R.drawable.d, R.drawable.e, R.drawable.f,
        R.drawable.g, R.drawable.h, R.drawable.i, R.drawable.j,
        R.drawable.k };

private ImageSwitcher imageSwitcher;
private Gallery gallery;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    imageSwitcher = (ImageSwitcher) this.findViewById(R.id.imageSwitcher);
    gallery = (Gallery) this.findViewById(R.id.gallery1);

    // 設置動畫效果
    imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
            android.R.anim.fade_in));
    imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
            android.R.anim.fade_out));

    imageSwitcher.setFactory(new ViewFactory() {

        @Override
        public View makeView() {
            ImageView imageView = new ImageView(MainActivity.this);
            imageView.setScaleType(ImageView.ScaleType.FIT_CENTER); // 設置保持縱橫比居中
            imageView.setLayoutParams(new ImageSwitcher.LayoutParams(
                    LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

            return imageView;
        }
    });

    GalleryAdapter adapter = new GalleryAdapter(MainActivity.this,imageId);
    gallery.setAdapter(adapter);
    gallery.setSelection(imageId.length / 2);
    gallery.setOnItemSelectedListener(new OnItemSelectedListener() {

        @Override
        public void onItemSelected(AdapterView<?> parent, View view,int position, long id) {
            imageSwitcher.setImageResource(imageId[position]);
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {

        }
    });
}

}</pre>

其中需要的一個適配器： 

import android.content.Context;
import android.content.res.TypedArray;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;

public class GalleryAdapter extends BaseAdapter {

private int[] imageId;

private Context mContext;

/**
 * 穿入上下文和圖片資源數組
 * @param mContext
 * @param imageId
 */
public GalleryAdapter(Context mContext, int[] imageId) {
    this.mContext = mContext;
    this.imageId = imageId;
}

@Override
public int getCount() {
    return imageId.length;
}

@Override
public Object getItem(int position) {
    return imageId[position];
}

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

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ImageView imageView1;
    if (convertView == null) {
        imageView1 = new ImageView(mContext);
        imageView1.setScaleType(ImageView.ScaleType.FIT_XY);
        imageView1.setLayoutParams(new Gallery.LayoutParams(180, 135));
        TypedArray typedArray = mContext
                .obtainStyledAttributes(R.styleable.Gallery);
        imageView1.setBackgroundResource(typedArray.getResourceId(
                R.styleable.Gallery_android_galleryItemBackground, 0));
        imageView1.setPadding(5, 0, 5, 0); // 設置ImageView的內邊距
    } else {
        imageView1 = (ImageView) convertView;
    }
    imageView1.setImageResource(imageId[position]); // 為ImageView設置要顯示的圖片
    return imageView1; // 返回ImageView
}


}</pre>