<declare-styleable name="RoundFrameLayout"> <attr name="Round" format="dimension" /> </declare-styleable> public class RoundFrameLayout extends FrameLayout { private final Path mPath; private final Paint mPaint; private final RectF mRectF; private final boolean isClipBackground; private float mRadius; @Keep public RoundFrameLayout(@NonNull Context context, @Nullable AttributeSet attrs) { super(context, attrs, 0); isClipBackground = true; mPath = new Path(); mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mRectF = new RectF(); mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN)); TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.RoundFrameLayout, 0, 0); mRadius = array.getDimension(R.styleable.RoundFrameLayout_Round, 50f); array.recycle(); } public void setRadius(float radius) { mRadius = radius; postInvalidate(); } @Keep @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); mRectF.set(0, 0, w, h); } @Keep @Override public void draw(Canvas canvas) { super.draw(canvas); if (Build.VERSION.SDK_INT >= P) { draw28(canvas); } else { draw27(canvas); } } @Keep @Override protected void dispatchDraw(Canvas canvas) { if (Build.VERSION.SDK_INT >= P) { dispatchDraw28(canvas); } else { dispatchDraw27(canvas); } } private void draw27(Canvas canvas) { if (isClipBackground) { canvas.saveLayer(mRectF, null, Canvas.ALL_SAVE_FLAG); super.draw(canvas); canvas.drawPath(genPath(), mPaint); canvas.restore(); } else { super.draw(canvas); } } private void draw28(Canvas canvas) { if (isClipBackground) { canvas.save(); canvas.clipPath(genPath()); super.draw(canvas); canvas.restore(); } else { super.draw(canvas); } } private void dispatchDraw27(Canvas canvas) { canvas.saveLayer(mRectF, null, Canvas.ALL_SAVE_FLAG); super.dispatchDraw(canvas); canvas.drawPath(genPath(), mPaint); canvas.restore(); } private void dispatchDraw28(Canvas canvas) { canvas.save(); canvas.clipPath(genPath()); super.dispatchDraw(canvas); canvas.restore(); } private Path genPath() { mPath.reset(); mPath.addRoundRect(mRectF, mRadius, mRadius, Path.Direction.CW); return mPath; } }