先看一下效果 再贴代码
自定义属性：
设置控件宽高：
左右移动算法：
完整代码 ：
private BitmapmBitmap; //生成位图
private double startX =0; //移动起始X坐标
private int screenWidth;
public static StringTAG ="MoveImageView";
private Timertimer;
private final int orientation;//默认向左
private double speed;
public MoveImageView(Context context, AttributeSet attrs) {
super(context, attrs);
if (contextinstanceof AppCompatActivity) {
((AppCompatActivity) (context)).getLifecycle().addObserver(this);
}
TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.MoveItemView);
orientation = ta.getInt(R.styleable.MoveItemView_orientation, 0);
speed = ta.getFloat(R.styleable.MoveItemView_speed, 0.1f);
Drawable drawable = ta.getDrawable(R.styleable.MoveItemView_img);
if (drawable !=null) {
Bitmap bitmap = drawableToBitamp(drawable);
setmBitmap(bitmap);
}
ta.recycle();
DisplayMetrics dm = context.getResources().getDisplayMetrics();
screenWidth = dm.widthPixels;
start();
}
private BitmapdrawableToBitamp(Drawable drawable) {
BitmapDrawable bd = (BitmapDrawable) drawable;
Bitmap bitmap = bd.getBitmap();
return bitmap;
}
public void setmBitmap(int res) {
mBitmap = BitmapFactory.decodeResource(getContext().getResources(), res);
}
private void setmBitmap(Bitmap bitmap) {
mBitmap = bitmap;
}
Handlerhandler;
public void start() {
handler =new Handler(Looper.getMainLooper()) {
public void handleMessage(Message msg) {
if (msg.what ==1) {
if (orientation ==0) {
startX -=speed;
}else {
startX +=speed;
}
}
invalidate();
}
};
timer =new Timer();
timer.schedule(new TimerTask() {
@Override
public void run() {
handler.removeCallbacksAndMessages(null);
handler.sendEmptyMessage(1);
}
//无延迟，10毫秒循环一次。
}, 0, 2);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mBitmap !=null) {
setMeasuredDimension(mBitmap.getWidth(), mBitmap.getHeight());
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
public void onResume() {
Log.d(TAG, "---onResume---");
if (handler !=null) {
handler.removeCallbacksAndMessages(null);
handler.sendEmptyMessage(1);
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
public void onPause() {
Log.d(TAG, "---onPause---");
if (handler !=null) {
handler.removeCallbacksAndMessages(null);
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
public void onDestroy() {
Log.d(TAG, "---onDestroy---");
if (timer !=null) {
timer.cancel();
}
if (handler !=null) {
handler.removeCallbacksAndMessages(null);
}
}
@Override
public void onDraw(Canvas canvas) {
if (mBitmap !=null) {
if (orientation ==0) {
moveLeft(canvas);
}else {
moveRight(canvas);
}
}
}
private void moveLeft(Canvas canvas) {
int page = (int) (Math.abs(startX) +screenWidth) /mBitmap.getWidth();
Log.d(TAG, "size=" + page +" startX=" +startX);
canvas.drawBitmap(mBitmap, (float)startX + (page -1) *mBitmap.getWidth(), 0, null);
canvas.drawBitmap(mBitmap, (float) (startX +mBitmap.getWidth() * page), 0, null);
}
private void moveRight(Canvas canvas) {
int page = (int) (startX /mBitmap.getWidth());
canvas.drawBitmap(mBitmap, (float)startX -mBitmap.getWidth() * page, 0, null);
canvas.drawBitmap(mBitmap, (float)startX -mBitmap.getWidth() * (page +1), 0, null);
}