移动开发-----自定义View（圆环）

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import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;


public class CircleView extends View {
    private Paint mPaint;
    private Paint mPaintBg;
    private RectF mRectF;
    private int mEndAngle = 120;
    private String mPaintColor = "#FFFFFF";

    public CircleView(Context context) {
        super(context);
        initData();
    }

    public CircleView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        initData();
    }

    public CircleView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initData();
    }

    private void initData() {
        mPaint = new Paint();
        mPaint.setStrokeWidth(100);
        mPaint.setColor(Color.parseColor(mPaintColor));
        mPaint.setAntiAlias(true);
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeCap(Paint.Cap.BUTT);
        mRectF = new RectF();

        mPaintBg = new Paint();
        mPaintBg.setStrokeWidth(100);
        mPaintBg.setColor(Color.parseColor("#36FFFFFF"));
        mPaintBg.setAntiAlias(true);
        mPaintBg.setStyle(Paint.Style.STROKE);
        mPaintBg.setStrokeCap(Paint.Cap.BUTT);
    }
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        int minSize = Math.min(getMeasuredWidth() - getPaddingLeft() - getPaddingRight(),
                getMeasuredHeight() - getPaddingTop() - getPaddingBottom());
        int roat = minSize / 2;
        int CenterPointX = getMeasuredWidth() / 2;
        int CenterPointY = getMeasuredHeight() / 2;
        mRectF.left = CenterPointX - roat + (int)mPaint.getStrokeWidth()/2;
        mRectF.top = CenterPointY - roat + (int)mPaint.getStrokeWidth()/2;
        mRectF.right = CenterPointX + roat -  (int)mPaint.getStrokeWidth()/2;
        mRectF.bottom = CenterPointY + roat -  (int)mPaint.getStrokeWidth()/2;
    }

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

        canvas.drawArc(mRectF,-90,mEndAngle,false,mPaint);
        canvas.drawArc(mRectF,0,360,false,mPaintBg);
        //增加锯齿
        for (int i = 0; i < 90 ; i++) {
            canvas.drawArc(mRectF,i * 4 ,2,false,mPaintBg);
        }
    }
    public void setEndAngle(int endAngle){
        this.mEndAngle = endAngle;
        invalidate();
    }

    public void setPaintColor(String paintColor){
        this.mPaintColor = paintColor;
        mPaint.setColor(Color.parseColor(this.mPaintColor));
        invalidate();
    }
}

效果图：