Android 省略号加载动画效果的实现思路

来源：互联网发布：java mysql学生编辑：程序博客网时间：2024/06/05 15:42
public class PointWaitBar extends LinearLayout {    private static final int NUM = 5;    private Context context;    private String TAG = "PointWaitBar";    private ImageView mOldIM;    private UpdateHandler handler;    public PointWaitBar(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        this.context = context;        init();    }    public PointWaitBar(Context context, AttributeSet attrs) {        super(context, attrs);        this.context = context;        init();    }    public PointWaitBar(Context context) {        super(context);        this.context = context;        init();    }    private void init() {        //初始化数据        this.setOrientation(LinearLayout.HORIZONTAL);        this.setGravity(Gravity.CENTER);        handler = new UpdateHandler(context);        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.point_waitingbar_black);        LinearLayout.LayoutParams tLayoutParams = new LinearLayout.LayoutParams(bitmap.getWidth(), bitmap.getHeight());        tLayoutParams.leftMargin = 10;        tLayoutParams.rightMargin = 10;        //添加5个小点省略号        for (int i = 0; i < NUM; i++) {            ImageView vDot = new ImageView(context);            vDot.setLayoutParams(tLayoutParams);            if (i == 0) {                vDot.setBackgroundResource(R.drawable.point_waitingbar_white);            } else {                vDot.setBackgroundResource(R.drawable.point_waitingbar_black);            }            this.addView(vDot);        }        mOldIM = (ImageView) this.getChildAt(0);        handler.sendEmptyMessage(0);    }    //提供给外部消除message    public void setDestroyCallBack() {        if (handler != null) {            handler.removeCallbacksAndMessages(null);            LogUtil.i(TAG, "已经清除消息");        }    }    class UpdateHandler extends Handler {        WeakReference<Context> reference;        public UpdateHandler(Context context) {            reference = new WeakReference<Context>(context);        }        @Override        public void handleMessage(Message msg) {            // TODO Auto-generated method stub            super.handleMessage(msg);            int cPosition = msg.what;            if (mOldIM != null)                mOldIM.setBackgroundResource(R.drawable.point_waitingbar_black);            ImageView currentIM = (ImageView) PointWaitBar.this.getChildAt(cPosition);            currentIM.setBackgroundResource(R.drawable.point_waitingbar_white);            mOldIM = currentIM;            if (++cPosition == NUM)                cPosition = 0;            this.sendEmptyMessageDelayed(cPosition, 200);        }    }}
阅读全文
0 0