Android - 圆角方线进度条

Answer 1

尝试这个简单的自定义类：

class V extends View {
    Path path = new Path();
    Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    float length;
    float[] intervals = {0, 0};

    public V(Context context) {
        super(context);
        paint.setColor(Color.GREEN);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(20);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        path.reset();
        RectF rect = new RectF(0, 0, w, h);
        float inset = paint.getStrokeWidth();
        rect.inset(inset, inset);

        path.addRoundRect(rect, 100, 100, Path.Direction.CW);
        length = new PathMeasure(path, false).getLength();
        intervals[0] = intervals[1] = length;
        PathEffect effect = new DashPathEffect(intervals, length);
        paint.setPathEffect(effect);
    }

    public void setProgress(int progress) {
        PathEffect effect = new DashPathEffect(intervals, length - length * progress / 100);
        paint.setPathEffect(effect);
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawPath(path, paint);
    }
}

测试代码（放入

Activity#onCreate

内）：

    LinearLayout ll = new LinearLayout(this);
    ll.setOrientation(LinearLayout.VERTICAL);
    SeekBar sb = new SeekBar(this);
    ll.addView(sb);
    final V v = new V(this);
    ll.addView(v);
    setContentView(ll);

    SeekBar.OnSeekBarChangeListener sbcl = new SeekBar.OnSeekBarChangeListener() {
        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            v.setProgress(progress);
        }
        @Override public void onStartTrackingTouch(SeekBar seekBar) {}
        @Override public void onStopTrackingTouch(SeekBar seekBar) {}
    };
    sb.setOnSeekBarChangeListener(sbcl);

Answer 2

我将 @pskink 的答案转换为 kotlin：

internal class V(context: Context?) : View(context) {
    var path: Path = Path()
    var paint: Paint = Paint(Paint.ANTI_ALIAS_FLAG)
    var length: Float = 0f
    var intervals: FloatArray = floatArrayOf(0f, 0f)

    init {
        paint.color = Color.GREEN
        paint.style = Paint.Style.STROKE
        paint.strokeWidth = 20f
    }

    override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
        path.reset()
        val rect = RectF(0f, 0f, w.toFloat(), h.toFloat())
        val inset = paint.strokeWidth
        rect.inset(inset, inset)

        path.addRoundRect(rect, 100f, 100f, Path.Direction.CW)
        length = PathMeasure(path, false).length
        intervals[1] = length
        intervals[0] = intervals[1]
        val effect: PathEffect = DashPathEffect(intervals, length)
        paint.setPathEffect(effect)
    }

    fun setProgress(progress: Int) {
        val effect: PathEffect = DashPathEffect(intervals, length - length * progress / 100)
        paint.setPathEffect(effect)
        invalidate()
    }

    override fun onDraw(canvas: Canvas) {
        canvas.drawPath(path, paint)
    }
}

测试代码在

Activity#onCreate

val ll = LinearLayout(this)
ll.orientation = LinearLayout.VERTICAL
val sb = SeekBar(this)
ll.addView(sb)
val v = V(this)
ll.addView(v)
setContentView(ll)

val sbcl: SeekBar.OnSeekBarChangeListener = object : SeekBar.OnSeekBarChangeListener {
    override fun onProgressChanged(seekBar: SeekBar, progress: Int, fromUser: Boolean) {
        v.setProgress(progress)
    }

    override fun onStartTrackingTouch(seekBar: SeekBar) {}
    override fun onStopTrackingTouch(seekBar: SeekBar) {}
}
sb.setOnSeekBarChangeListener(sbcl)