Android 自定义圆形头像控件

1.在 res>>values里面新建attrs.xml文件，写入以下内容：
 <!-- 圆形头像 -->
    <declare-styleable name="CircleImageView">
        <attr name="civ_border_width" format="dimension"></attr>
        <attr name="civ_border_color" format="color"></attr>
        <attr name="civ_border_overlay" format="boolean"></attr>
        <attr name="civ_fill_color" format="color"></attr>
    </declare-styleable>  
2.新建一个CircleImageView类

 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;

    private static final int DEFAULT_BORDER_WIDTH = 0;

    private static final int DEFAULT_BORDER_COLOR = Color.BLACK;

    private static final int DEFAULT_FILL_COLOR = Color.TRANSPARENT;

    private static final boolean DEFAULT_BORDER_OVERLAY = false;

    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 final Paint mFillPaint = new Paint();

    private int mBorderColor = DEFAULT_BORDER_COLOR;

    private int mBorderWidth = DEFAULT_BORDER_WIDTH;

    private int mFillColor = DEFAULT_FILL_COLOR;

    private Bitmap mBitmap;

    private BitmapShader mBitmapShader;

    private int mBitmapWidth;

    private int mBitmapHeight;

    private float mDrawableRadius;

    private float mBorderRadius;

    private ColorFilter mColorFilter;

    private boolean mReady;

    private boolean mSetupPending;

    private boolean mBorderOverlay;

    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);

        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleImageView, defStyle, 0);

        mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_civ_border_width, DEFAULT_BORDER_WIDTH);

        mBorderColor = a.getColor(R.styleable.CircleImageView_civ_border_color, DEFAULT_BORDER_COLOR);

        mBorderOverlay = a.getBoolean(R.styleable.CircleImageView_civ_border_overlay, DEFAULT_BORDER_OVERLAY);

        mFillColor = a.getColor(R.styleable.CircleImageView_civ_fill_color, DEFAULT_FILL_COLOR);

        a.recycle();

        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 (mBitmap == null) {

            return;

        }

        if (mFillColor != Color.TRANSPARENT) {

            canvas.drawCircle(getWidth() / 2.0f, getHeight() / 2.0f, mDrawableRadius, mFillPaint);

        }

        canvas.drawCircle(getWidth() / 2.0f, getHeight() / 2.0f, mDrawableRadius, mBitmapPaint);

        if (mBorderWidth != 0) {

            canvas.drawCircle(getWidth() / 2.0f, getHeight() / 2.0f, 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 void setBorderColorResource(int borderColorRes) {

        setBorderColor(getContext().getResources().getColor(borderColorRes));

    }

    public int getFillColor() {

        return mFillColor;

    }

    public void setFillColor(int fillColor) {

        if (fillColor == mFillColor) {

            return;

        }

        mFillColor = fillColor;

        mFillPaint.setColor(fillColor);

        invalidate();

    }

    public void setFillColorResource( int fillColorRes) {

        setFillColor(getContext().get
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Resources().getColor(fillColorRes));

    }

    public int getBorderWidth() {

        return mBorderWidth;

    }

    public void setBorderWidth(int borderWidth) {

        if (borderWidth == mBorderWidth) {

            return;

        }

        mBorderWidth = borderWidth;

        setup();

    }

    public boolean isBorderOverlay() {

        return mBorderOverlay;

    }

    public void setBorderOverlay(boolean borderOverlay) {

        if (borderOverlay == mBorderOverlay) {

            return;

        }

        mBorderOverlay = borderOverlay;

        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 = uri != null ? getBitmapFromDrawable(getDrawable()) : null;

        setup();

    }

    @Override

    public void setColorFilter(ColorFilter cf) {

        if (cf == mColorFilter) {

            return;

        }

        mColorFilter = cf;

        mBitmapPaint.setColorFilter(mColorFilter);

        invalidate();

    }

    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 (Exception e) {

            e.printStackTrace();

            return null;

        }

    }

    private void setup() {

        if (!mReady) {

            mSetupPending = true;

            return;

        }

        if (getWidth() == 0 && getHeight() == 0) {

            return;

        }

        if (mBitmap == null) {

            invalidate();

            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);

        mFillPaint.setStyle(Paint.Style.FILL);

        mFillPaint.setAntiAlias(true);

        mFillPaint.setColor(mFillColor);

        mBitmapHeight = mBitmap.getHeight();

        mBitmapWidth = mBitmap.getWidth();

        mBorderRect.set(0, 0, getWidth(), getHeight());

        mBorderRadius = Math.min((mBorderRect.height() - mBorderWidth) / 2.0f, (mBorderRect.width() - mBorderWidth) / 2.0f);

        mDrawableRect.set(mBorderRect);

        if (!mBorderOverlay) {

            mDrawableRect.inset(mBorderWidth, mBorderWidth);

        }

        mDrawableRadius = Math.min(mDrawableRect.height() / 2.0f, mDrawableRect.width() / 2.0f);

        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() / mBitmapHeight;

            dx = (mDrawableRect.width() - mBitmapWidth * scale) * 0.5f;

        } else {

            scale = mDrawableRect.width() / mBitmapWidth;

            dy = (mDrawableRect.height() - mBitmapHeight * scale) * 0.5f;

        }

        mShaderMatrix.setScale(scale, scale);

        mShaderMatrix.postTranslate((int) (dx + 0.5f) + mDrawableRect.left, (int) (dy + 0.5f) + mDrawableRect.top);

        mBitmapShader.setLocalMatrix(mShaderMatrix);

    }

}
3.在所用的布局文件中引用自定义控件，包名+类名