下面列出了android.graphics.Canvas#drawCircle ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。
/**
* Draw the progress spinner
*/
public void draw(Canvas c, Rect bounds) {
final RectF arcBounds = mTempBounds;
arcBounds.set(bounds);
arcBounds.inset(mStrokeInset, mStrokeInset);
final float startAngle = (mStartTrim + mRotation) * 360;
final float endAngle = (mEndTrim + mRotation) * 360;
float sweepAngle = endAngle - startAngle;
mPaint.setColor(mCurrentColor);
c.drawArc(arcBounds, startAngle, sweepAngle, false, mPaint);
drawTriangle(c, startAngle, sweepAngle, bounds);
if (mAlpha < 255) {
mCirclePaint.setColor(mBackgroundColor);
mCirclePaint.setAlpha(255 - mAlpha);
c.drawCircle(bounds.exactCenterX(), bounds.exactCenterY(), bounds.width() / 2,
mCirclePaint);
}
}
public static Bitmap getCroppedBitmapDrawable(Bitmap bitmap) {
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xff424242;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
// canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
canvas.drawCircle(bitmap.getWidth() / 2, bitmap.getHeight() / 2,
bitmap.getWidth() / 2, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
//Bitmap _bmp = Bitmap.createScaledBitmap(output, 60, 60, false);
//return _bmp;
return output;
}
@Override
public void draw(Canvas canvas) {
final boolean positionChanged = adapterPositionChanged();
if (rippleOverlay) {
if (!positionChanged) {
rippleBackground.draw(canvas);
}
super.draw(canvas);
if (!positionChanged) {
if (rippleRoundedCorners != 0) {
Path clipPath = new Path();
RectF rect = new RectF(0, 0, canvas.getWidth(), canvas.getHeight());
clipPath.addRoundRect(rect, rippleRoundedCorners, rippleRoundedCorners, Path.Direction.CW);
canvas.clipPath(clipPath);
}
canvas.drawCircle(currentCoords.x, currentCoords.y, radius, paint);
}
} else {
if (!positionChanged) {
rippleBackground.draw(canvas);
canvas.drawCircle(currentCoords.x, currentCoords.y, radius, paint);
}
super.draw(canvas);
}
}
@Override
public void draw(final Canvas c, final Projection pj) {
if (this.mLocation != null) {
pj.toPixels(this.mLocation, screenCoords);
if (this.mShowAccuracy && this.mAccuracy > 10) {
final float accuracyRadius = pj.metersToEquatorPixels(this.mAccuracy);
/* Only draw if the DirectionArrow doesn't cover it. */
if (accuracyRadius > 8) {
/* Draw the inner shadow. */
this.mAccuracyPaint.setAntiAlias(false);
this.mAccuracyPaint.setAlpha(30);
this.mAccuracyPaint.setStyle(Style.FILL);
c.drawCircle(screenCoords.x, screenCoords.y, accuracyRadius,
this.mAccuracyPaint);
/* Draw the edge. */
this.mAccuracyPaint.setAntiAlias(true);
this.mAccuracyPaint.setAlpha(150);
this.mAccuracyPaint.setStyle(Style.STROKE);
c.drawCircle(screenCoords.x, screenCoords.y, accuracyRadius,
this.mAccuracyPaint);
}
}
/*
* Rotate the direction-Arrow according to the bearing we are driving. And draw it to
* the canvas.
*/
this.directionRotater.setRotate(this.mBearing, DIRECTION_ARROW_CENTER_X,
DIRECTION_ARROW_CENTER_Y);
final Bitmap rotatedDirection = Bitmap.createBitmap(DIRECTION_ARROW, 0, 0,
DIRECTION_ARROW_WIDTH, DIRECTION_ARROW_HEIGHT, this.directionRotater, false);
c.drawBitmap(rotatedDirection, screenCoords.x - rotatedDirection.getWidth() / 2,
screenCoords.y - rotatedDirection.getHeight() / 2, this.mPaint);
}
}
/**
* 把bitmap变圆
*
* @param bitmap
* @return
*/
private Bitmap getCircleBitmap(Bitmap bitmap) {
//创建一个Bitmap，准备在上面作画
Bitmap base = Bitmap.createBitmap(getMeasuredWidth(), getMeasuredHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(base);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
//防抖动
paint.setDither(true);
//先在base上画一个圆
canvas.drawCircle(getMeasuredWidth() / 2
, getMeasuredHeight() / 2
, getMeasuredWidth() / 2, paint);
//设置为SRC_IN
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
//再在base上画上传进来的bitmap，注意坐标对应（这里从原点开始）
canvas.drawBitmap(bitmap, 0, 0, paint);
//回收
bitmap.recycle();
bitmap = null;
return base;
}
@Override
public void drawIcon(Canvas canvas, float fraction, Drawable drawable, int colorOfIcon,
WidthAndHeightOfView widthAndHeightOfView) {
float newFraction = fraction / 0.65f;
int centerX = widthAndHeightOfView.getWidth() / 2;
int centerY = widthAndHeightOfView.getHeight() / 2 - 150;
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
canvas.save();
paint.setColor(Color.parseColor("#e53935"));
if (newFraction <= 0.33f) {
canvas.drawCircle(centerX, centerY - 50, 100 * (newFraction / 0.33f), paint);
} else {
canvas.drawCircle(centerX, centerY - 50, 100, paint);
}
if (newFraction > 0.33f) {
paint.setColor(Color.parseColor("#fdd835"));
if (newFraction <= 0.66f)
canvas.drawCircle(centerX -35, centerY + 35,100 * ((newFraction - 0.33f) / 0.33f), paint);
else
canvas.drawCircle(centerX -35, centerY + 35,100, paint);
}
if (newFraction > 0.66f) {
paint.setColor(Color.parseColor("#1e88e5"));
if (newFraction <= 1f)
canvas.drawCircle(centerX + 35, centerY + 35, 100 * ((newFraction - 0.66f) / 0.34f), paint);
else
canvas.drawCircle(centerX + 35, centerY + 35, 100, paint);
}
canvas.restore();
}
@Override
protected void onDraw(Canvas canvas) {
setClickable(true);
canvas.drawCircle(getWidth() / 2, getHeight() / 2, (float) (getWidth() / 2.6), mButtonPaint);
canvas.drawBitmap(mBitmap, (getWidth() - mBitmap.getWidth()) / 2,
(getHeight() - mBitmap.getHeight()) / 2, mDrawablePaint);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// draw all pointers
for (int size = mActivePointers.size(), i = 0; i < size; i++) {
PointF point = mActivePointers.valueAt(i);
if (point != null)
mPaint.setColor(colors[i % 9]);
canvas.drawCircle(point.x, point.y, SIZE, mPaint);
}
canvas.drawText("Total pointers: " + mActivePointers.size(), 10, 40 , textPaint);
}
private void play(Canvas canvas, int mTimer) {
int alpha = 5; // 透明度从5开始
for (int i=0; i<=mTimer; i++) {
alpha += 2; // 每绘制一个外圆，透明度加2
mPaint.setAlpha(alpha);
mPaint.setStrokeWidth(2);
canvas.drawCircle(mBitmapWidth/2, mBitmapHeight/2, mInnerRadius+i, mPaint);
}
}
@Override
public void draw(Canvas canvas, Paint paint) {
final int viewWidth = SHCircleProgressBar.this.getWidth();
final int viewHeight = SHCircleProgressBar.this.getHeight();
canvas.drawCircle(viewWidth / 2, viewHeight / 2, (mCircleDiameter / 2 + mShadowRadius),
mShadowPaint);
canvas.drawCircle(viewWidth / 2, viewHeight / 2, (mCircleDiameter / 2), paint);
}
@Override
public void draw(Canvas canvas, Paint paint) {
final int viewWidth = CircleImageView.this.getWidth();
final int viewHeight = CircleImageView.this.getHeight();
canvas.drawCircle(viewWidth / 2, viewHeight / 2, viewWidth / 2, mShadowPaint);
canvas.drawCircle(viewWidth / 2, viewHeight / 2, viewWidth / 2 - mShadowRadius, paint);
}
@Override
public Bitmap generateIdenticonBitmap(byte[] hash) {
if (hash.length < 16)
return null;
Bitmap bmp = Bitmap.createBitmap(SIZE, SIZE, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bmp);
canvas.drawColor(BG_COLOR);
int blue = (hash[13] & 0x01f) << 3;
int green = (hash[14] & 0x01f) << 3;
int red = (hash[15] & 0x01f) << 3;
int color = Color.rgb(red, green, blue);
if (getColorDistance(color, BG_COLOR) <= 64.0) {
color = getComplementaryColor(color);
}
Paint p = new Paint();
p.setColor(color);
p.setStyle(Paint.Style.FILL_AND_STROKE);
p.setAntiAlias(true);
for (int y = 0; y < 5; y++) {
for (int x = 0; x < 5; x++) {
final int index = y * 5 + x;
float radius;
if ((index & 1) == 0) {
radius = hash[index/2] & 0x0F;
} else {
radius = (hash[index/2] >> 4) & 0x0F;
}
canvas.drawCircle(x * SIZE / 5 + SIZE / 10, y * SIZE / 5 + SIZE / 10, radius, p);
}
}
return bmp;
}
public static Bitmap createCircle(int width, int height) {
Paint paint = new Paint();
paint.setStyle(Paint.Style.FILL);
paint.setColor(Color.BLUE);
Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
float radius = Math.min(width, height) * 0.45f;
canvas.drawCircle(width / 2, height / 2, radius, paint);
return bitmap;
}
@Override
protected void onDraw(Canvas canvas) {
canvas.save();
canvas.translate(mRadius, mRadius);
for (int i = 0; i < mBallCenters.length; i++) {
mPaint.setColor(COLORS[i]);
PointF mCurrentCenter = getCurrentCenter(i, mPercent);
canvas.drawCircle(mCurrentCenter.x, mCurrentCenter.y, mRadius, mPaint);
}
canvas.restore();
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawCircle(mX, mY, MAX_SIZE / mTouches, mPaint);
}
@Override
protected void onDraw(Canvas canvas) {
if (freeform) {
int lineThickness = AndroidUtilities.dp(2);
int handleSize = AndroidUtilities.dp(16);
int handleThickness = AndroidUtilities.dp(3);
int originX = (int) actualRect.left - lineThickness;
int originY = (int) actualRect.top - lineThickness;
int width = (int) (actualRect.right - actualRect.left) + lineThickness * 2;
int height = (int) (actualRect.bottom - actualRect.top) + lineThickness * 2;
if (dimVisibile) {
canvas.drawRect(0, 0, getWidth(), originY + lineThickness, dimPaint);
canvas.drawRect(0, originY + lineThickness, originX + lineThickness, originY + height - lineThickness, dimPaint);
canvas.drawRect(originX + width - lineThickness, originY + lineThickness, getWidth(), originY + height - lineThickness, dimPaint);
canvas.drawRect(0, originY + height - lineThickness, getWidth(), getHeight(), dimPaint);
}
if (!frameVisible) {
return;
}
int inset = handleThickness - lineThickness;
int gridWidth = width - handleThickness * 2;
int gridHeight = height - handleThickness * 2;
GridType type = gridType;
if (type == GridType.NONE && gridProgress > 0)
type = previousGridType;
shadowPaint.setAlpha((int) (gridProgress * 26));
linePaint.setAlpha((int) (gridProgress * 178));
for (int i = 0; i < 3; i++) {
if (type == GridType.MINOR) {
for (int j = 1; j < 4; j++) {
if (i == 2 && j == 3)
continue;
canvas.drawLine(originX + handleThickness + gridWidth / 3 / 3 * j + gridWidth / 3 * i, originY + handleThickness, originX + handleThickness + gridWidth / 3 / 3 * j + gridWidth / 3 * i, originY + handleThickness + gridHeight, shadowPaint);
canvas.drawLine(originX + handleThickness + gridWidth / 3 / 3 * j + gridWidth / 3 * i, originY + handleThickness, originX + handleThickness + gridWidth / 3 / 3 * j + gridWidth / 3 * i, originY + handleThickness + gridHeight, linePaint);
canvas.drawLine(originX + handleThickness, originY + handleThickness + gridHeight / 3 / 3 * j + gridHeight / 3 * i, originX + handleThickness + gridWidth, originY + handleThickness + gridHeight / 3 / 3 * j + gridHeight / 3 * i, shadowPaint);
canvas.drawLine(originX + handleThickness, originY + handleThickness + gridHeight / 3 / 3 * j + gridHeight / 3 * i, originX + handleThickness + gridWidth, originY + handleThickness + gridHeight / 3 / 3 * j + gridHeight / 3 * i, linePaint);
}
} else if (type == GridType.MAJOR) {
if (i > 0) {
canvas.drawLine(originX + handleThickness + gridWidth / 3 * i, originY + handleThickness, originX + handleThickness + gridWidth / 3 * i, originY + handleThickness + gridHeight, shadowPaint);
canvas.drawLine(originX + handleThickness + gridWidth / 3 * i, originY + handleThickness, originX + handleThickness + gridWidth / 3 * i, originY + handleThickness + gridHeight, linePaint);
canvas.drawLine(originX + handleThickness, originY + handleThickness + gridHeight / 3 * i, originX + handleThickness + gridWidth, originY + handleThickness + gridHeight / 3 * i, shadowPaint);
canvas.drawLine(originX + handleThickness, originY + handleThickness + gridHeight / 3 * i, originX + handleThickness + gridWidth, originY + handleThickness + gridHeight / 3 * i, linePaint);
}
}
}
canvas.drawRect(originX + inset, originY + inset, originX + width - inset, originY + inset + lineThickness, framePaint);
canvas.drawRect(originX + inset, originY + inset, originX + inset + lineThickness, originY + height - inset, framePaint);
canvas.drawRect(originX + inset, originY + height - inset - lineThickness, originX + width - inset, originY + height - inset, framePaint);
canvas.drawRect(originX + width - inset - lineThickness, originY + inset, originX + width - inset, originY + height - inset, framePaint);
canvas.drawRect(originX, originY, originX + handleSize, originY + handleThickness, handlePaint);
canvas.drawRect(originX, originY, originX + handleThickness, originY + handleSize, handlePaint);
canvas.drawRect(originX + width - handleSize, originY, originX + width, originY + handleThickness, handlePaint);
canvas.drawRect(originX + width - handleThickness, originY, originX + width, originY + handleSize, handlePaint);
canvas.drawRect(originX, originY + height - handleThickness, originX + handleSize, originY + height, handlePaint);
canvas.drawRect(originX, originY + height - handleSize, originX + handleThickness, originY + height, handlePaint);
canvas.drawRect(originX + width - handleSize, originY + height - handleThickness, originX + width, originY + height, handlePaint);
canvas.drawRect(originX + width - handleThickness, originY + height - handleSize, originX + width, originY + height, handlePaint);
} else {
if (circleBitmap == null || circleBitmap.getWidth() != actualRect.width()) {
if (circleBitmap != null) {
circleBitmap.recycle();
circleBitmap = null;
}
try {
circleBitmap = Bitmap.createBitmap((int) actualRect.width(), (int) actualRect.height(), Bitmap.Config.ARGB_8888);
Canvas circleCanvas = new Canvas(circleBitmap);
circleCanvas.drawRect(0, 0, actualRect.width(), actualRect.height(), dimPaint);
circleCanvas.drawCircle(actualRect.width() / 2, actualRect.height() / 2, actualRect.width() / 2, eraserPaint);
circleCanvas.setBitmap(null);
} catch (Throwable ignore) {
}
}
canvas.drawRect(0, 0, getWidth(), (int) actualRect.top, dimPaint);
canvas.drawRect(0, (int) actualRect.top, (int) actualRect.left, (int) actualRect.bottom, dimPaint);
canvas.drawRect((int) actualRect.right, (int) actualRect.top, getWidth(), (int) actualRect.bottom, dimPaint);
canvas.drawRect(0, (int) actualRect.bottom, getWidth(), getHeight(), dimPaint);
if (circleBitmap != null) {
canvas.drawBitmap(circleBitmap, (int) actualRect.left, (int) actualRect.top, null);
}
}
}
@Override
protected void onDraw(Canvas canvas) {
int radius = (Math.min(getWidth(), getHeight())) / 2;
canvas.drawCircle(radius, radius, radius - rippleStrokeWidth, paint);
}
private void drawEdges(Canvas canvas) {
final float[] p = mTrapezoid.getScreenPoints(getMatrix());
Path path = new Path();
path.moveTo((int) p[0], (int) p[1]);
path.lineTo((int) p[2], (int) p[3]);
path.lineTo((int) p[4], (int) p[5]);
path.lineTo((int) p[6], (int) p[7]);
path.close();
path.computeBounds(mPathBounds, false);
mPathBounds.round(mPathBoundsRounded);
canvas.getClipBounds(mCanvasCLipRect);
mContext.getDrawingRect(mViewDrawingRect);
mTopRect.set(0, 0, mViewDrawingRect.right, getDrawRect().top);
mRightRect.set(0, getDrawRect().top, getDrawRect().left, getDrawRect().bottom);
mLeftRect.set(getDrawRect().right, getDrawRect().top, mViewDrawingRect.right, getDrawRect().bottom);
mBottomRect.set(0, getDrawRect().bottom, mViewDrawingRect.right, mViewDrawingRect.bottom);
canvas.drawRect(mTopRect, mFocusPaint);
canvas.drawRect(mRightRect, mFocusPaint);
canvas.drawRect(mLeftRect, mFocusPaint);
canvas.drawRect(mBottomRect, mFocusPaint);
if (mCanvasCLipRect.contains(mPathBoundsRounded)) {
canvas.save();
canvas.clipRect(getDrawRect());
path.setFillType(Path.FillType.INVERSE_EVEN_ODD);
canvas.drawPath(path, mFocusPaint);
canvas.restore();
}
canvas.drawLine(p[0], p[1], p[2], p[3], mOutlinePaint);
canvas.drawLine(p[2], p[3], p[4], p[5], mOutlinePaint);
canvas.drawLine(p[4], p[5], p[6], p[7], mOutlinePaint);
canvas.drawLine(p[0], p[1], p[6], p[7], mOutlinePaint);
canvas.drawCircle(p[0], p[1], mCropCornerHandleRadius, mOutlinePaint);
canvas.drawCircle(p[2], p[3], mCropCornerHandleRadius, mOutlinePaint);
canvas.drawCircle(p[4], p[5], mCropCornerHandleRadius, mOutlinePaint);
canvas.drawCircle(p[6], p[7], mCropCornerHandleRadius, mOutlinePaint);
float x = (p[0] + p[2]) / 2;
float y = (p[1] + p[3]) / 2;
canvas.drawCircle(x, y, mCropEdgeHandleRadius, mOutlinePaint);
x = (p[2] + p[4]) / 2;
y = (p[3] + p[5]) / 2;
canvas.drawCircle(x, y, mCropEdgeHandleRadius, mOutlinePaint);
x = (p[4] + p[6]) / 2;
y = (p[5] + p[7]) / 2;
canvas.drawCircle(x, y, mCropEdgeHandleRadius, mOutlinePaint);
x = (p[0] + p[6]) / 2;
y = (p[1] + p[7]) / 2;
canvas.drawCircle(x, y, mCropEdgeHandleRadius, mOutlinePaint);
}
@SuppressLint("DrawAllocation")
@Override
protected void onDraw(@NonNull Canvas canvas) {
int width = getWidth();
int center = width / 2;
canvas.drawCircle(center, center, (center * 19) / 20f, mBackgroundPaint);
int size = center / 10;
//sun line
if (mShowSun) {
canvas.drawLine(center, center, (float) (center - 0.9 * center * Math.cos(Math.toRadians(mCurrentAngle))),
(float) (center - 0.9 * center * Math.sin(Math.toRadians(mCurrentAngle))), mYellowPaint);
canvas.save();
canvas.clipPath(mClipPath);
canvas.drawCircle((float) (center - 0.85 * center * Math.cos(Math.toRadians(mCurrentAngle))),
(float) (center - 0.85 * center * Math.sin(Math.toRadians(mCurrentAngle))), size, mSunPaint);
canvas.restore();
}
float nightAngle = (float) (mSunriseAngle - mSunsetAngle);
canvas.drawArc(new RectF(center - center * 0.9f, center - center * 0.9f, center + center * 0.9f, center + center * 0.9f),
(float) -mSunriseAngle + 90, nightAngle, true, mNightPaint);
float sw = mYellowPaint.getStrokeWidth() / 2;
canvas.drawArc(new RectF(center - center * 0.9f + sw, center - center * 0.9f + sw, center + center * 0.9f - sw, center + center * 0.9f - sw),
(float) -mSunriseAngle + 90, -(360 - nightAngle), false, mYellowPaint);
canvas.drawCircle(center, center, center / 10f, mCenterPaint);
int y = center - center / 2;
mKaabe.setBounds(center - size, y - size, center + size, y + size);
mKaabe.draw(canvas);
canvas.drawCircle(center, center, (center * 19) / 20f, mOuterStrokePaint);
float textShift = center / 30f;
if (mQiblaTime != null) {
if (mQiblaTime.getFront() != null) {
canvas.drawPath(mTopPath, mTrianglePaint);
canvas.drawText(mQiblaTime.getFront(), center, center - center * 0.9f + textShift, mTextPaint);
}
if (mQiblaTime.getLeft() != null) {
canvas.drawPath(mLeftPath, mTrianglePaint);
canvas.drawText(mQiblaTime.getLeft(), center - center * 0.84f, center + textShift, mTextPaint);
}
if (mQiblaTime.getRight() != null) {
canvas.drawPath(mRightPath, mTrianglePaint);
canvas.drawText(mQiblaTime.getRight(), center + center * 0.84f, center + textShift, mTextPaint);
}
if (mQiblaTime.getBack() != null) {
canvas.drawPath(mBottomPath, mTrianglePaint);
canvas.drawText(mQiblaTime.getBack(), center, center + center * 0.9f + textShift, mTextPaint);
}
}
}
@Override
protected void onDraw(Canvas canvas) {
if (radius == -1) {
radius = getHeight() < getWidth() ? getHeight() : getWidth();
radius = (int) (radius * 0.65 / 2);
double circumference = 2 * Math.PI * radius;
paint.setStrokeWidth((float) (circumference / 120));
circlePaint.setStyle(Paint.Style.STROKE);
circlePaint.setStrokeWidth(4);
}
circlePaint.setColor(color);
canvas.drawCircle(getWidth() / 2, getHeight() / 2, radius, circlePaint);
if (bytes != null) {
if (points == null || points.length < bytes.length * 4) {
points = new float[bytes.length * 4];
}
double angle = 0;
for (int i = 0; i < 120; i++, angle += 3) {
int x = (int) Math.ceil(i * 8.5);
int t = ((byte) (-Math.abs(bytes[x]) + 128)) * (getHeight() / 4) / 128;
points[i * 4] = (float) (getWidth() / 2
+ radius
* Math.cos(Math.toRadians(angle)));
points[i * 4 + 1] = (float) (getHeight() / 2
+ radius
* Math.sin(Math.toRadians(angle)));
points[i * 4 + 2] = (float) (getWidth() / 2
+ (radius + t)
* Math.cos(Math.toRadians(angle)));
points[i * 4 + 3] = (float) (getHeight() / 2
+ (radius + t)
* Math.sin(Math.toRadians(angle)));
}
canvas.drawLines(points, paint);
}
super.onDraw(canvas);
}