图片循环滚动控件ScrollingImageView

来源：互联网发布：淘宝刷销量平台可靠吗编辑：程序博客网时间：2024/06/05 20:33
设置一个图片，控件可以自动循环滚动，单张图片首尾拼接
/** * 可滚动的ImageView控件，使用startRolling(int) 或者 startRolling(Bitmap)启动滚动 * @author brian512 */public class ScrollingImageView extends View {    public final float SPEED_SLOW = 1f;    public final float SPEED_NORMAL = 3f;    public final float SPEED_FAST = 10f;    private Bitmap mBitmap;    private int mResourceID = 0;    private float mSpeed = SPEED_NORMAL;    private Rect clipBounds = new Rect(); // 用于保存边界信息    private float offset = 0; // 记录起始位置，需要拼接    private boolean mIsScrolling; // 标记是否开始滚动    public ScrollingImageView(Context context) {        this(context, null, 0);    }    public ScrollingImageView(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public ScrollingImageView(Context context, AttributeSet attrs, int styleID) {        super(context, attrs, styleID);        //startScroll(R.drawable.loading_bg);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);//        setMeasuredDimension(MeasureSpec.getSize(widthMeasureSpec), heightMeasureSpec);    }    @Override    public void onDraw(Canvas canvas) {        super.onDraw(canvas);        if (canvas == null) {            return;        }        Bitmap bitmap = getBitmap();        if (bitmap == null || bitmap.isRecycled()) {            return;        }        canvas.getClipBounds(clipBounds);        int width = bitmap.getWidth();        while (offset <= -width) {            offset += width;        }        float left = offset;        while (left < clipBounds.width()) {            canvas.drawBitmap(bitmap, getBitmapLeft(width, left), 0, null);            left += width;        }        if (mIsScrolling && mSpeed != 0) {            offset -= Math.abs(mSpeed);            postInvalidateOnAnimation();        }    }    private Bitmap getBitmap() {        if (mBitmap == null) {            mBitmap = BitmapFactory.decodeResource(getResources(), mResourceID);        }        return mBitmap;    }    private float getBitmapLeft(float layerWidth, float left) {        if (mSpeed < 0) {            return clipBounds.width() - layerWidth - left;        } else {            return left;        }    }    /**     * 开始滚动     */    public void startScroll(int imageID) {        if (imageID <= 0) {            return;        }        mResourceID = imageID;        start();    }    /**     * 开始滚动     */    public void startScroll(Bitmap bitmap) {        if (bitmap == null || bitmap.isRecycled()) {            return;        }        mBitmap = bitmap;        start();    }    private void start() {        if (!mIsScrolling) {            mIsScrolling = true;            postInvalidateOnAnimation();        }    }    /**     * 停止滚动     */    public void stop() {        if (mIsScrolling) {            mIsScrolling = false;            invalidate();        }    }    /**     * 设置滚动速度     * @param speed 速度，默认为 SPEED_NORMAL = 3f     */    public void setSpeed(float speed) {        this.mSpeed = speed;        if (mIsScrolling) {            postInvalidateOnAnimation();        }    }    /**     * 获取滚动速度     * @return     */    public float getSpeed() {        return mSpeed;    }    /**     * 是否在滚动     * @return     */    public boolean getIsScrolling() {        return mIsScrolling;    }}
参考github开源项目：
https://github.com/Q42/AndroidScrollingImageView
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