Android实现圆形图片的两种方式

public class CircleImageView extends ImageView {   private static final ScaleType SCALE_TYPE = ScaleType.CENTER_CROP;   private static final Bitmap.Config BITMAP_CONFIG = Bitmap.Config.ARGB_8888;  private static final int COLORDRAWABLE_DIMENSION = 2;   // 圆形边框的厚度默认值。  // 如果是0，则没有天蓝色渐变的边框。  private static final int DEFAULT_BORDER_WIDTH = 0;   private static final int DEFAULT_BORDER_COLOR = Color.BLACK;   private final RectF mDrawableRect = new RectF();  private final RectF mBorderRect = new RectF();   private final Matrix mShaderMatrix = new Matrix();  private final Paint mBitmapPaint = new Paint();  private final Paint mBorderPaint = new Paint();   private int mBorderColor = DEFAULT_BORDER_COLOR;  private int mBorderWidth = DEFAULT_BORDER_WIDTH;   private Bitmap mBitmap;  private BitmapShader mBitmapShader;  private int mBitmapWidth;  private int mBitmapHeight;   private float mDrawableRadius;  private float mBorderRadius;   private boolean mReady;  private boolean mSetupPending;  private final Paint mFlagBackgroundPaint = new Paint();  private final TextPaint mFlagTextPaint = new TextPaint();  private String mFlagText;  private boolean mShowFlag = false;  private Rect mFlagTextBounds = new Rect();   Shader mSweepGradient = null;   public CircleImageView(Context context) {   super(context);    init();  }   public CircleImageView(Context context, AttributeSet attrs) {   this(context, attrs, 0);  }   public CircleImageView(Context context, AttributeSet attrs, int defStyle) {   super(context, attrs, defStyle);    init();  }   private void init() {   super.setScaleType(SCALE_TYPE);   mReady = true;    if (mSetupPending) {    setup();    mSetupPending = false;   }  }   @Override  public ScaleType getScaleType() {   return SCALE_TYPE;  }   @Override  public void setScaleType(ScaleType scaleType) {   if (scaleType != SCALE_TYPE) {    throw new IllegalArgumentException(String.format(      "ScaleType %s not supported.", scaleType));   }  }   @Override  public void setAdjustViewBounds(boolean adjustViewBounds) {   if (adjustViewBounds) {    throw new IllegalArgumentException(      "adjustViewBounds not supported.");   }  }   @Override  protected void onDraw(Canvas canvas) {   if (getDrawable() == null) {    return;   }    canvas.drawCircle(getWidth() / 2, getHeight() / 2, mDrawableRadius,     mBitmapPaint);   if (mBorderWidth != 0) {    canvas.save();    canvas.rotate(20, getWidth() / 2, getHeight() / 2);    canvas.drawCircle(getWidth() / 2, getHeight() / 2, mBorderRadius,      mBorderPaint);    canvas.restore();   }    if (mShowFlag && mFlagText != null) {    canvas.drawArc(mBorderRect, 40, 100, false, mFlagBackgroundPaint);    mFlagTextPaint.getTextBounds(mFlagText, 0, mFlagText.length(),      mFlagTextBounds);    canvas.drawText(mFlagText, getWidth() / 2,      (float) ((3 + Math.cos((float) (Math.PI * 5 / 18)))             * getHeight() / 4 + mFlagTextBounds.height() / 3),      mFlagTextPaint);    }   }   @Override  protected void onSizeChanged(int w, int h, int oldw, int oldh) {   super.onSizeChanged(w, h, oldw, oldh);   setup();  }   public int getBorderColor() {   return mBorderColor;  }   public void setBorderColor(int borderColor) {   if (borderColor == mBorderColor) {    return;   }    mBorderColor = borderColor;   mBorderPaint.setColor(mBorderColor);   invalidate();  }   public int getBorderWidth() {   return mBorderWidth;  }   /**   * @param borderWidth   *   圆形的边框厚度。   */  public void setBorderWidth(int borderWidth) {   if (borderWidth == mBorderWidth) {    return;   }    mBorderWidth = borderWidth;   setup();  }   @Override  public void setImageBitmap(Bitmap bm) {   super.setImageBitmap(bm);   mBitmap = bm;   setup();  }   @Override  public void setImageDrawable(Drawable drawable) {   super.setImageDrawable(drawable);   mBitmap = getBitmapFromDrawable(drawable);   setup();  }   @Override  public void setImageResource(int resId) {   super.setImageResource(resId);   mBitmap = getBitmapFromDrawable(getDrawable());   setup();  }   @Override  public void setImageURI(Uri uri) {   super.setImageURI(uri);   mBitmap = getBitmapFromDrawable(getDrawable());   setup();  }   private Bitmap getBitmapFromDrawable(Drawable drawable) {   if (drawable == null) {    return null;   }    if (drawable instanceof BitmapDrawable) {    return ((BitmapDrawable) drawable).getBitmap();   }    try {    Bitmap bitmap;     if (drawable instanceof ColorDrawable) {     bitmap = Bitmap.createBitmap(COLORDRAWABLE_DIMENSION,       COLORDRAWABLE_DIMENSION, BITMAP_CONFIG);    } else {     bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),       drawable.getIntrinsicHeight(), BITMAP_CONFIG);    }     Canvas canvas = new Canvas(bitmap);    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());    drawable.draw(canvas);    return bitmap;   } catch (OutOfMemoryError e) {    return null;   }  }   private void setup() {   if (!mReady) {    mSetupPending = true;    return;   }    if (mBitmap == null) {    return;   }    mBitmapShader = new BitmapShader(mBitmap, Shader.TileMode.CLAMP,     Shader.TileMode.CLAMP);    mBitmapPaint.setAntiAlias(true);   mBitmapPaint.setShader(mBitmapShader);    mBorderPaint.setStyle(Paint.Style.STROKE);   mBorderPaint.setAntiAlias(true);   mBorderPaint.setColor(mBorderColor);   mBorderPaint.setStrokeWidth(mBorderWidth);    mBitmapHeight = mBitmap.getHeight();   mBitmapWidth = mBitmap.getWidth();    mBorderRect.set(0, 0, getWidth(), getHeight());   mBorderRadius = Math.min((mBorderRect.height() - mBorderWidth) / 2,     (mBorderRect.width() - mBorderWidth) / 2);    mDrawableRect.set(mBorderWidth, mBorderWidth, mBorderRect.width()     - mBorderWidth, mBorderRect.height() - mBorderWidth);   mDrawableRadius = Math.min(mDrawableRect.height() / 2,     mDrawableRect.width() / 2);    mFlagBackgroundPaint.setColor(Color.BLACK & 0x66FFFFFF);   mFlagBackgroundPaint.setFlags(TextPaint.ANTI_ALIAS_FLAG);    mFlagTextPaint.setFlags(TextPaint.ANTI_ALIAS_FLAG);   mFlagTextPaint.setTextAlign(Align.CENTER);   mFlagTextPaint.setColor(Color.WHITE);   mFlagTextPaint     .setTextSize(getResources().getDisplayMetrics().density * 18);    mSweepGradient = new SweepGradient(getWidth() / 2, getHeight() / 2,     new int[] { Color.rgb(255, 255, 255), Color.rgb(1, 209, 255) },     null);    mBorderPaint.setShader(mSweepGradient);    updateShaderMatrix();   invalidate();  }   private void updateShaderMatrix() {   float scale;   float dx = 0;   float dy = 0;    mShaderMatrix.set(null);    if (mBitmapWidth * mDrawableRect.height() > mDrawableRect.width()     * mBitmapHeight) {    scale = mDrawableRect.height() / (float) mBitmapHeight;    dx = (mDrawableRect.width() - mBitmapWidth * scale) * 0.5f;   } else {    scale = mDrawableRect.width() / (float) mBitmapWidth;    dy = (mDrawableRect.height() - mBitmapHeight * scale) * 0.5f;   }    mShaderMatrix.setScale(scale, scale);   mShaderMatrix.postTranslate((int) (dx + 0.5f) + mBorderWidth,     (int) (dy + 0.5f) + mBorderWidth);    mBitmapShader.setLocalMatrix(mShaderMatrix);  }   public void setShowFlag(boolean show) {   mShowFlag = show;   invalidate();  }   public void setFlagText(String text) {   mFlagText = text;   invalidate();  } } 

/**   * 将图片剪裁为圆形   */  public static Bitmap createCircleImage(Bitmap source) {   int length = source.getWidth() < source.getHeight() ? source.getWidth() : source.getHeight();   Paint paint = new Paint();   paint.setAntiAlias(true);   Bitmap target = Bitmap.createBitmap(length, length, Bitmap.Config.ARGB_8888);   Canvas canvas = new Canvas(target);   canvas.drawCircle(length / 2, length / 2, length / 2, paint);   paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));   canvas.drawBitmap(source, 0, 0, paint);   return target;  } 

//从ImageView中获取bitmap   Bitmap bm =((BitmapDrawable) ( imageView).getDrawable()).getBitmap();