[置顶] Android(安卓)Gallery用法（自定义边框+底部小圆点）

最近在项目中用到图片轮播，试了Gallery，ViewFlipper，ViewPager,感觉Gallery最符合需求，但是Gallery的系统边框很难看，项目中要求用自己的背景图片。

下面来看一下使用Gallery实现图片轮播

运行效果：

布局文件：

    <FrameLayout        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:paddingLeft="16dp"        android:paddingRight="16dp"        android:paddingTop="10dp" >        <Gallery            android:id="@+id/gallery"            android:layout_width="fill_parent"            android:layout_height="wrap_content"            android:fadingEdge="none"            android:spacing="0dp" />        <RelativeLayout            android:layout_width="fill_parent"            android:layout_height="18dp"            android:layout_gravity="bottom"            android:layout_marginBottom="3dp"            android:layout_marginLeft="3dp"            android:layout_marginRight="3dp"            android:background="#80776f63"            android:gravity="center" >            <ImageView                android:id="@+id/dot_1"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:src="@drawable/ic_dot_normal" />            <ImageView                android:id="@+id/dot_2"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:layout_marginLeft="10dp"                android:layout_toRightOf="@+id/dot_1"                android:src="@drawable/ic_dot_normal" />            <ImageView                android:id="@+id/dot_3"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:layout_marginLeft="10dp"                android:layout_marginRight="10dp"                android:layout_toRightOf="@+id/dot_2"                android:src="@drawable/ic_dot_normal" />        </RelativeLayout>    </FrameLayout>

其中，android:fadingEdge="none"消除图片两边的阴影。使用FrameLayout在底部显示小圆点

public class MainActivity extends Activity {private Gallery mGallery;private int index = 0;// 记录选中的图片位置private ImageView[] mImageViewIds;// 小圆点ImageView数组private static final int IMAGE_COUNT = 3;// 小圆点个数@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);findViews();mImageViewIds[0].setImageDrawable(getBaseContext().getResources().getDrawable(R.drawable.ic_dot_focused));ImageAdapteradapter = new ImageAdapter(this);mGallery.setAdapter(adapter);Timer timer = new Timer();timer.schedule(task, 2000, 2000);mGallery.setOnItemSelectedListener(onItemSelectedListener);mGallery.setOnItemClickListener(onItemClickListener);}private void findViews() {mGallery = (Gallery) findViewById(R.id.gallery);mImageViewIds = new ImageView[] { (ImageView) findViewById(R.id.dot_1),(ImageView) findViewById(R.id.dot_2),(ImageView) findViewById(R.id.dot_3) };}private TimerTask task = new TimerTask() {@Overridepublic void run() {Message message = new Message();message.what = 2;index = mGallery.getSelectedItemPosition();index++;handler.sendMessage(message);}};/** * 开一个线程执行耗时操作 */private Handler handler = new Handler() {@Overridepublic void handleMessage(Message msg) {super.handleMessage(msg);switch (msg.what) {case 2:mGallery.setSelection(index);break;default:break;}}};/** * 设置小圆点显示，position会一直增加，如果要循环显示图片，需要对position取余，否则数组越界 */private OnItemSelectedListener onItemSelectedListener = new OnItemSelectedListener() {@Overridepublic void onItemSelected(AdapterView<?> parent, View view,int position, long id) {int pos = position % IMAGE_COUNT;mImageViewIds[pos].setImageDrawable(getBaseContext().getResources().getDrawable(R.drawable.ic_dot_focused));if (pos > 0) {mImageViewIds[pos - 1].setImageDrawable(getBaseContext().getResources().getDrawable(R.drawable.ic_dot_normal));}if (pos < (IMAGE_COUNT - 1)) {mImageViewIds[pos + 1].setImageDrawable(getBaseContext().getResources().getDrawable(R.drawable.ic_dot_normal));}if (pos == 0) {mImageViewIds[IMAGE_COUNT - 1].setImageDrawable(getBaseContext().getResources().getDrawable(R.drawable.ic_dot_normal));}}@Overridepublic void onNothingSelected(AdapterView<?> arg0) {// TODO Auto-generated method stub}};/** * 点击事件，点击图片进入SecondActivity */private OnItemClickListener onItemClickListener = new OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> arg0, View arg1, int pos,long arg3) {Intent intent = new Intent();intent.setClass(MainActivity.this, SecondActivity.class);startActivity(intent);}};}

ImageAdapter类，重写android.widget.BaseAdapter，用于描述图像信息。

public class ImageAdapter extends BaseAdapter {private Context context;private int[] mImages = { R.drawable.bg_timeline_01,R.drawable.bg_timeline_02, R.drawable.bg_timeline_03 };private static final int IMAGE_PX_HEIGHT = 198;public ImageAdapter(Context context) {this.context = context;}@Overridepublic int getCount() {return Integer.MAX_VALUE;//实现循环显示}@Overridepublic Object getItem(int position) {return position;}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {ImageView imageView = new ImageView(context);imageView.setImageResource(mImages[position % mImages.length]);imageView.setScaleType(ImageView.ScaleType.CENTER);imageView.setLayoutParams(new Gallery.LayoutParams(Gallery.LayoutParams.FILL_PARENT, IMAGE_PX_HEIGHT));RelativeLayout borderImg = new RelativeLayout(context);borderImg.setPadding(2, 2, 2, 2);borderImg.setBackgroundResource(R.drawable.bg_gallery);//设置ImageView边框borderImg.addView(imageView);return borderImg;}}

如果用系统背景，可以这样写

int mGalleryItemBackground;private Context mContext; public ImageAdapter(Context context){mContext = context;// 获得Gallery组件的属性TypedArray typedArray = obtainStyledAttributes(R.styleable.Gallery);mGalleryItemBackground = typedArray.getResourceId(R.styleable.Gallery_android_galleryItemBackground, 0); }

在getview中设置

imageView.setBackgroundResource(mGalleryItemBackground);

Gallery组件属性信息定义在res\values\attrs.xml

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

详细讲解见 http://www.eoeandroid.com/forum.php?mod=viewthread&tid=182297

自定义边框参考http://stackoverflow.com/questions/4830173/change-border-style-in-gallery

下面是控制gallery滑动过快的方法，重写gallery的手势操作

public class MyGallery extends Gallery {public MyGallery(Context context) {super(context);// TODO Auto-generated constructor stub}public MyGallery(Context context, AttributeSet attrs) {super(context, attrs);// TODO Auto-generated constructor stub}private boolean isScrollingLeft(MotionEvent e1, MotionEvent e2) {return e2.getX() > e1.getX();}public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,float velocityY) {int keyCode;if (isScrollingLeft(e1, e2)) {keyCode = KeyEvent.KEYCODE_DPAD_LEFT;} else {keyCode = KeyEvent.KEYCODE_DPAD_RIGHT;}onKeyDown(keyCode, null);return true;}}

源码下载地址： http://download.csdn.net/detail/welovesunflower/6910441

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