自定义进度条

public class LightSeekBar extends View {

//资源图片
private Bitmap bitmap;
//画笔
private Paint mPaint;
//上次手指离开屏幕时的位置
private float xLast = 0.0f;
//每个单元的宽度
private int width = 0;
//单元内的文字
private List<String> points;
//结束时监听回调
private OnLightSeekBarChangeListener onLightSeekBarChangeListener;


/**
 * 构造方法
 *
 * @param context
 */
public LightSeekBar(Context context) {
    super(context);
    init(context);
}


public LightSeekBar(Context context, AttributeSet attrs) {
    super(context, attrs);
    init(context);
}


private void init(Context context) {
    bitmap = BitmapUtil.readBitMap(context, R.drawable.mycar_setting_light_seekbar_btn);
    mPaint = new Paint();
    points = Arrays.asList(new String[]{"10%", "20%", "30%", "40%", "50%", "60%", "70%", "80%", "90%", "100%"});

}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    drawTxt(canvas);
    drawImg(canvas, xLast);
}


/**
 * 手指触摸事件
 *
 * @param event
 * @return
 */
@Override
public boolean onTouchEvent(MotionEvent event) {
    switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
        case MotionEvent.ACTION_MOVE:
            invalidateImg(event);
            break;
        case MotionEvent.ACTION_UP:
            onFinish();
            break;
    }
    return true;
}


@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

/**
 * 手指离开屏幕时，设置滑块的位置
 */
private int onFinish() {
    int point = 10;
    if (xLast < width * 0.5) {
        xLast = 0;
        point = 10;
    } else if (xLast < width * 1.5f) {
        xLast = width;
        point = 20;
    } else if (xLast < width * 2.5f) {
        xLast = width * 2;
        point = 30;
    } else if (xLast < width * 3.5f) {
        xLast = width * 3;
        point = 40;
    } else if (xLast < width * 4.5f) {
        xLast = width * 4;
        point = 50;
    } else if (xLast < width * 5.5f) {
        xLast = width * 5;
        point = 60;
    } else if (xLast < width * 6.5f) {
        xLast = width * 6;
        point = 70;
    } else if (xLast < width * 7.5f) {
        xLast = width * 7;
        point = 80;
    } else if (xLast < width * 8.5f) {
        xLast = width * 8;
        point = 90;
    } else {
        xLast = width * 9;
        point = 100;
    }
    invalidate();
    onChange(point);
    return point;
}

/**
 * 绘制文字
 *
 * @param canvas
 */
private void drawTxt(Canvas canvas) {

// //绘制底色 // canvas.drawARGB(255, 0, 0, 0);

    int maxWidth = getWidth();
    if (0 == maxWidth) {
        throw new RuntimeException("cant get width");
    } else {
        if (width == 0) {
            width = maxWidth / points.size();

        }
        mPaint.setAlpha(255);
        mPaint.setAntiAlias(true);
        mPaint.setColor(Color.YELLOW);
        if (port) {
            mPaint.setTextSize(30);
        } else {
            mPaint.setTextSize(45);
        }
        mPaint.setTextAlign(Paint.Align.CENTER);
        for (int i = 0; i < points.size(); i++) {
            canvas.drawText(points.get(i), (int) ((i + 0.5) * width), 80, mPaint);
        }
    }
}


/**
 * 画遮挡层
 *
 * @param canvas
 * @param x
 */
private void drawImg(Canvas canvas, float x) {


    //计算bitmap缩放比例
    int newWidth = width;
    int newHeight = getHeight();

    float scaleWidth = ((float) newWidth) / bitmap.getWidth();
    float scaleHeight = ((float) newHeight) / bitmap.getHeight();

    Matrix matrix = new Matrix();
    matrix.postScale(scaleWidth, scaleHeight);
    Bitmap target = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
    canvas.drawBitmap(target, x, 0, mPaint);


    mPaint.setColor(Color.rgb(13, 13, 13));
    //绘制左侧黑色遮挡层
    canvas.drawRect(0, 0, xLast, getHeight(), mPaint);
    //绘制右侧黑色遮挡层
    canvas.drawRect(xLast + width, 0, getWidth(), getHeight(), mPaint);
}


/**
 * 根据手指位置，重新绘制Bitmap和遮挡层
 *
 * @param event
 */
private void invalidateImg(MotionEvent event) {
    xLast = event.getX() - (int) (0.5f * width);
    if (-0.5f <= xLast && xLast <= width * 9 + 0.5f) {
        invalidate();
    }
}

/**
 * 暴露一个方法，供外部调用
 *
 * @param progress
 */
private void onChange(int progress) {
    if (onLightSeekBarChangeListener != null) {
        onLightSeekBarChangeListener.onLightChange(progress);
    }
}

public void setOnLightSeekBarChangeListener(OnLightSeekBarChangeListener onLightSeekBarChangeListener) {
    this.onLightSeekBarChangeListener = onLightSeekBarChangeListener;
}

/**
 * SeekBar  手指抬起时的监听
 */
public interface OnLightSeekBarChangeListener {
    void onLightChange(int progress);
}

public void setCurrentProgress(int progress) {
    if (width == 0) {
        width = getWidth() / points.size();
    }
    xLast = (float)( ((progress - 10)/ 10) * width);
    invalidate();
}

public int getCurrentProgress() {
    return onFinish();
}

}

来源：oschina

链接：https://my.oschina.net/u/2517638/blog/692107