Android利用CircleImageView实现圆形头像的方法

<?xml version="1.0" encoding="utf-8"?><resources> <declare-styleable name="CircleImageView"> <attr name="border_width" format="dimension" /> <attr name="border_color" format="color" /> </declare-styleable></resources>

import android.content.Context;import android.content.res.TypedArray;import android.graphics.Bitmap;import android.graphics.BitmapShader;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.RectF;import android.graphics.Shader;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.ColorDrawable;import android.graphics.drawable.Drawable;import android.util.AttributeSet;import android.widget.ImageView;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 = 1; 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; public CircleImageView(Context context) { super(context); } public CircleImageView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public CircleImageView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); super.setScaleType(SCALE_TYPE); TypedArray a = context.obtainStyledAttributes(attrs,  R.styleable.CircleImageView, defStyle, 0); mBorderWidth = a.getDimensionPixelSize(  R.styleable.CircleImageView_border_width, DEFAULT_BORDER_WIDTH); mBorderColor = a.getColor(R.styleable.CircleImageView_border_color,  DEFAULT_BORDER_COLOR); a.recycle(); 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 protected void onDraw(Canvas canvas) { if (getDrawable() == null) {  return; } canvas.drawCircle(getWidth() / 2, getHeight() / 2, mDrawableRadius,  mBitmapPaint); if (mBorderWidth != 0) {  canvas.drawCircle(getWidth() / 2, getHeight() / 2, mBorderRadius,  mBorderPaint); } } @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; } 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(); } 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); 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); }}

 <com.example.suqh.drop.CircleImageView  android:layout_width="match_parent"  android:layout_height="match_parent"  android:src="@drawable/img3" />