android 打造不同的Seekbar

时间:2022-04-26
本文章向大家介绍android 打造不同的Seekbar,主要内容包括其使用实例、应用技巧、基本知识点总结和需要注意事项,具有一定的参考价值,需要的朋友可以参考一下。

最近项目需要用到双向的seekbar,网上找了好多野不能达到要求,偶然一次机会看到了大众点评的例子,然后我最他做了优化,并对常用的seekbar做了总结.

向上两张图:

比如双向seekbar

public class SimpleRangeSeekBar extends View {

    private int lineWidth = 5;
    private int textSize = 25;

    private int inRangeColor = 0xff26b5f5;
    private int outRangeColor = 0xffC2C2C2;
    private int textColor = 0xff0000ff;

    private int textMarginBottom = 10;
    private int lowerCenterX;
    private int upperCenterX;

    private int bmpWidth;
    private int bmpHeight;

    private Bitmap lowerBmp;
    private Bitmap upperBmp;

    private boolean isLowerMoving = false;
    private boolean isUpperMoving = false;

    private OnRangeChangedListener onRangeChangedListener;

    private int paddingLeft = 50;
    private int paddingRight = 50;
    private int paddingTop = 10;
    private int paddingBottom = 10;

    private int lineHeight=20;
    private int lineLength = Utils.getScreenWidth(getContext())-paddingLeft-paddingRight-50;
    private int lineStart = paddingLeft;
    private int lineEnd = lineLength + paddingLeft;

    private int smallRange = 0;
    private int maxRange = 100;

    private int textHeight;

    public SimpleRangeSeekBar(Context context, AttributeSet attrs) {
        this(context, attrs,-1);
    }

    public SimpleRangeSeekBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context, attrs, defStyle);
    }

    private void init(Context context, AttributeSet attrs, int defStyle) {
        initAttr(context, attrs, defStyle);
        initView();
    }

    private void initView() {
        lowerBmp = BitmapFactory.decodeResource(getResources(),
                R.drawable.seekbar_n);
        upperBmp = BitmapFactory.decodeResource(getResources(),
                R.drawable.seekbar_n);
        bmpWidth = upperBmp.getWidth();
        bmpHeight = upperBmp.getHeight();

        lowerCenterX = lineStart;
        upperCenterX = lineEnd;

        lineHeight = getHeight() - paddingBottom - lowerBmp.getHeight() / 2;
        textHeight = lineHeight + lowerBmp.getHeight() / 2 + 10;
    }

    private void initAttr(Context context, AttributeSet attrs, int defStyle) {
        TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.RangeSeekBar, defStyle, 0);
//        lineWidth = typedArray.getDimensionPixelSize(R.styleable.RangeSeekBar_layout_width, UIUtils.getScreenWidth(getContext())-paddingLeft-paddingRight-50);
//        lineHeight=typedArray.getDimensionPixelSize(R.styleable.RangeSeekBar_layout_height,15);

        paddingLeft = typedArray.getDimensionPixelSize(R.styleable.RangeSeekBar_paddingLeft, 50);
        paddingRight= typedArray.getDimensionPixelSize(R.styleable.RangeSeekBar_paddingRight, 50);
        paddingTop= typedArray.getDimensionPixelSize(R.styleable.RangeSeekBar_paddingTop, 30);
        paddingBottom= typedArray.getDimensionPixelSize(R.styleable.RangeSeekBar_paddingBottom, 20);

        smallRange = typedArray.getInt(R.styleable.RangeSeekBar_line_small_range,0);
        maxRange = typedArray.getInt(R.styleable.RangeSeekBar_line_max_range,100);
        typedArray.recycle();
    }


    private int measureWidth(int measureSpec) {
        int result = 0;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);
        if (specMode == MeasureSpec.EXACTLY) {
            result = specSize;
        } else {
            result = paddingLeft + paddingRight + bmpWidth * 2;
            if (specMode == MeasureSpec.AT_MOST) {
                result = Math.min(result, specSize);
            }
        }
        return result;
    }

    private int measureHeight(int measureHeight) {
        int result = 0;

        int specMode = MeasureSpec.getMode(measureHeight);
        int specSize = MeasureSpec.getSize(measureHeight);

        if (specMode == MeasureSpec.EXACTLY) {
            result = bmpHeight * 2;
        } else {
            result = bmpHeight + paddingTop;
            if (specMode == MeasureSpec.AT_MOST) {
                result = Math.min(result, specSize);
            }
        }
        return result;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        widthMeasureSpec = measureWidth(widthMeasureSpec);
        heightMeasureSpec = measureHeight(heightMeasureSpec);
        setMeasuredDimension(widthMeasureSpec, heightMeasureSpec);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        bmpWidth = upperBmp.getWidth();
        bmpHeight = upperBmp.getHeight();
        lineHeight = getHeight() - paddingBottom - lowerBmp.getHeight() / 2;
        textHeight = lineHeight - bmpHeight / 2 - textMarginBottom;
        // 画线
        Paint linePaint = new Paint();
        linePaint.setAntiAlias(true);
        linePaint.setStrokeWidth(lineWidth);
        // 绘制处于图片滑块之间线段
        linePaint.setColor(inRangeColor);
        canvas.drawLine(lowerCenterX, lineHeight, upperCenterX, lineHeight,
                linePaint);
        // 绘制处于图片滑块两端的线段
        linePaint.setColor(outRangeColor);
        canvas.drawLine(lineStart, lineHeight, lowerCenterX, lineHeight,
                linePaint);
        canvas.drawLine(upperCenterX, lineHeight, lineEnd, lineHeight,
                linePaint);
        // 画图片滑块
        Paint bmpPaint = new Paint();
        canvas.drawBitmap(lowerBmp, lowerCenterX - bmpWidth / 2, lineHeight
                - bmpHeight / 2, bmpPaint);
        canvas.drawBitmap(lowerBmp, upperCenterX - bmpWidth / 2, lineHeight
                - bmpHeight / 2, bmpPaint);

        // 画范围文字
        drawText(canvas);
    }

    private void drawText(Canvas canvas) {
        Paint textPaint = new Paint();
        textPaint.setColor(textColor);
        textPaint.setTextSize(textSize);
        textPaint.setAntiAlias(true);
        textPaint.setStrokeWidth(lineWidth);
        canvas.drawText(String.valueOf(smallRange), lowerCenterX
                - bmpWidth / 2, textHeight, textPaint);
        canvas.drawText(String.valueOf(maxRange), upperCenterX
                - bmpWidth / 2, textHeight, textPaint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        super.onTouchEvent(event);

        float xPos = event.getX();
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                // 如果按下的位置在垂直方向没有与图片接触,则不会滑动滑块
                float yPos = event.getY();
                if (Math.abs(yPos - lineHeight) > bmpHeight / 2) {
                    return false;
                }
                // 表示当前按下的滑块是左边的滑块
                if (Math.abs(xPos - lowerCenterX) < bmpWidth / 2) {
                    isLowerMoving = true;
                }

                // //表示当前按下的滑块是右边的滑块
                if (Math.abs(xPos - upperCenterX) < bmpWidth / 2) {
                    isUpperMoving = true;
                }

                // 单击左边滑块的左边线条时,左边滑块滑动到对应的位置
                if (xPos >= lineStart && xPos <= lowerCenterX - bmpWidth / 2) {
                    lowerCenterX = (int) xPos;
                    updateRange();
                    postInvalidate();
                }

                // 单击右边滑块的右边线条时, 右边滑块滑动到对应的位置
                if (xPos <= lineEnd && xPos >= upperCenterX + bmpWidth / 2) {
                    upperCenterX = (int) xPos;
                    updateRange();
                    postInvalidate();
                }
                break;
            case MotionEvent.ACTION_MOVE:
                if (isLowerMoving) {
                    if (xPos >= lineStart && xPos < upperCenterX - bmpWidth) {
                        lowerCenterX = (int) xPos;
                        updateRange();
                        postInvalidate();
                    }
                }
                if (isUpperMoving) {
                    if (xPos > lowerCenterX + bmpWidth && xPos < lineEnd) {
                        upperCenterX = (int) xPos;
                        updateRange();
                        postInvalidate();
                    }
                }

                break;
            case MotionEvent.ACTION_UP:
                isLowerMoving = false;
                isUpperMoving = false;
                break;
            default:
                break;
        }

        return true;
    }

    private int computeRange(int range) {
        return (range - lineStart) * (maxRange - smallRange) / lineLength
                + smallRange;
    }

    private void updateRange() {
        smallRange = computeRange(lowerCenterX);
        maxRange = computeRange(upperCenterX);

        if (null != onRangeChangedListener) {
            onRangeChangedListener.onRangeChanged(smallRange, maxRange);
        }
    }

    public void setOnRangeChangedListener(
            OnRangeChangedListener onRangeChangedListener) {
        this.onRangeChangedListener = onRangeChangedListener;
    }

    public interface OnRangeChangedListener {
         void onRangeChanged(int lowRange, int maxRange);
    }
}

为了方便大家使用我使用了自定义属性方便大家配置。

大家有兴趣还是去我的链接下载吧

http://download.csdn.net/detail/xiangzhihong8/9578539