转圈进度条

来源：互联网发布：淘宝流量闭环什么意思编辑：程序博客网时间：2024/05/16 01:12

效果图

public class RCircleView extends View {    private Paint paint;    private int color = 0xff04ade5;    private int degree;//让画布旋转一个角度再画图，就像圈圈一直在转一样    public RCircleView(Context context) {        this(context, null);    }    public RCircleView(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public RCircleView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        init(context);    }    private void init(Context context) {        paint = new Paint(Paint.ANTI_ALIAS_FLAG);        new Thread(new Runnable() {            @Override            public void run() {                while (true) {                    try {                        Thread.sleep(150);                        degree += 30;                        if (degree == 360) {                            degree = 0;                        }                        postInvalidate();                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                }            }        }).start();    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        int heightMode = MeasureSpec.getMode(heightMeasureSpec);        int heightSize = MeasureSpec.getSize(heightMeasureSpec);        int widthMode = MeasureSpec.getMode(widthMeasureSpec);        int widthSize = MeasureSpec.getSize(widthMeasureSpec);        int w = 0, h = 0;        if (widthMode == MeasureSpec.EXACTLY) {            w = widthSize;        } else {            w = dp2px(80);        }        if (heightMode == MeasureSpec.EXACTLY) {            h = heightSize;        } else {            h = dp2px(80);        }        setMeasuredDimension(w, h);    }    private int dp2px(int dp) {        float density = getContext().getResources().getDisplayMetrics().density;        return (int) (dp * density + 0.5);    }    @Override    protected void onDraw(Canvas canvas) {        canvas.save();        //画布默认是在左上角旋转，移动位置到控件中间再旋转，旋转完成后再移动回去        canvas.translate(getWidth() / 2, getHeight() / 2);        canvas.rotate(degree);        canvas.translate(-getWidth() / 2, -getHeight() / 2);        onDrawCircle(canvas);        canvas.restore();    }    private void onDrawCircle(Canvas canvas) {        float cx = getWidth() / 2, cy = getHeight() / 2;        float r = Math.min(getWidth(), getHeight()) * 5.0f / 12;//要画的小圆圈距中心的距离        for (int i = 1; i <= 12; i++) {            float angle = (float) (i * Math.PI / 6);            //xy是小圆圈的圆点坐标            float x = (float) (cx + r * Math.sin(angle));            float y = (float) (cy - r * Math.cos(angle));            float rr = r / 5;//最大小圆点的半径            rr *= (10.0f / 33 + i * 1.0f / 33);//第i个小圆点的半径            int alpha = (int) (i * 255.f / 12);//第i个圆点的透明度            paint.setColor((alpha << 24) | (color & 0x00ffffff));            canvas.drawCircle(x, y, rr, paint);//画圆点        }    }}

要说的只有圆点的透明度，color&0x00ffffff得到颜色的agb不带透明度，alpha后面24位表示rgb，左移24位得到0xff000000这样的只带透明度的。和色值|之后就得到完整色值。

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