CircleImageView的使用

简介：

• 实现对一个图片进行圆形切割，并作为头像使用，因为在使用的过程中涉及备份到云端，那么就会出现重新加载的图片出现毛边，为了解决毛边的问题，在头像的周围添加一个圆框即可，在github上有一个开源控件叫做CircleImageView可以很好的实现圆形边框

使用：

• 在build.gradle的dependencies中加入

dependencies {
    ....
    implementation 'de.hdodenhof:circleimageview:3.0.0'
}

• 在布局文件中引入CircleImageView

• 可以看出我们可以像使用ImageVIew那样使用CircleImageView, 但是使用的具体方法我们要到源码中去查看，下面我贴了一下CircleImageVIew的源码：

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_CIRCLE_BACKGROUND_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 mCircleBackgroundPaint = new Paint();



    private int mBorderColor = DEFAULT_BORDER_COLOR;
    private int mBorderWidth = DEFAULT_BORDER_WIDTH;
    private int mCircleBackgroundColor = DEFAULT_CIRCLE_BACKGROUND_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;
    private boolean mDisableCircularTransformation;



    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);
        mCircleBackgroundColor = a.getColor(R.styleable.CircleImageView_civ_circle_background_color, DEFAULT_CIRCLE_BACKGROUND_COLOR);



        a.recycle();



        init();
    }



    private void init() {
        super.setScaleType(SCALE_TYPE);
        mReady = true;



        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            setOutlineProvider(new OutlineProvider());
        }



        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 (mDisableCircularTransformation) {
            super.onDraw(canvas);
            return;
        }



        if (mBitmap == null) {
            return;
        }



        if (mCircleBackgroundColor != Color.TRANSPARENT) {
            canvas.drawCircle(mDrawableRect.centerX(), mDrawableRect.centerY(), mDrawableRadius, mCircleBackgroundPaint);
        }
        canvas.drawCircle(mDrawableRect.centerX(), mDrawableRect.centerY(), mDrawableRadius, mBitmapPaint);
        if (mBorderWidth > 0) {
            canvas.drawCircle(mBorderRect.centerX(), mBorderRect.centerY(), mBorderRadius, mBorderPaint);
        }
    }



    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        setup();
    }



    @Override
    public void setPadding(int left, int top, int right, int bottom) {
        super.setPadding(left, top, right, bottom);
        setup();
    }



    @Override
    public void setPaddingRelative(int start, int top, int end, int bottom) {
        super.setPaddingRelative(start, top, end, bottom);
        setup();
    }



    public int getBorderColor() {
        return mBorderColor;
    }



    public void setBorderColor(@ColorInt int borderColor) {
        if (borderColor == mBorderColor) {
            return;
        }



        mBorderColor = borderColor;
        mBorderPaint.setColor(mBorderColor);
        invalidate();
    }



    public int getCircleBackgroundColor() {
        return mCircleBackgroundColor;
    }



    public void setCircleBackgroundColor(@ColorInt int circleBackgroundColor) {
        if (circleBackgroundColor == mCircleBackgroundColor) {
            return;
        }



        mCircleBackgroundColor = circleBackgroundColor;
        mCircleBackgroundPaint.setColor(circleBackgroundColor);
        invalidate();
    }



    public void setCircleBackgroundColorResource(@ColorRes int circleBackgroundRes) {
        setCircleBackgroundColor(getContext().getResources().getColor(circleBackgroundRes));
    }



    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();
    }



    public boolean isDisableCircularTransformation() {
        return mDisableCircularTransformation;
    }



    public void setDisableCircularTransformation(boolean disableCircularTransformation) {
        if (mDisableCircularTransformation == disableCircularTransformation) {
            return;
        }



        mDisableCircularTransformation = disableCircularTransformation;
        initializeBitmap();
    }



    @Override
    public void setImageBitmap(Bitmap bm) {
        super.setImageBitmap(bm);
        initializeBitmap();
    }



    @Override
    public void setImageDrawable(Drawable drawable) {
        super.setImageDrawable(drawable);
        initializeBitmap();
    }



    @Override
    public void setImageResource(@DrawableRes int resId) {
        super.setImageResource(resId);
        initializeBitmap();
    }



    @Override
    public void setImageURI(Uri uri) {
        super.setImageURI(uri);
        initializeBitmap();
    }



    @Override
    public void setColorFilter(ColorFilter cf) {
        if (cf == mColorFilter) {
            return;
        }



        mColorFilter = cf;
        applyColorFilter();
        invalidate();
    }



    @Override
    public ColorFilter getColorFilter() {
        return mColorFilter;
    }



    private void applyColorFilter() {
        mBitmapPaint.setColorFilter(mColorFilter);
    }



    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 initializeBitmap() {
        if (mDisableCircularTransformation) {
            mBitmap = null;
        } else {
            mBitmap = getBitmapFromDrawable(getDrawable());
        }
        setup();
    }



    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);



        mCircleBackgroundPaint.setStyle(Paint.Style.FILL);
        mCircleBackgroundPaint.setAntiAlias(true);
        mCircleBackgroundPaint.setColor(mCircleBackgroundColor);



        mBitmapHeight = mBitmap.getHeight();
        mBitmapWidth = mBitmap.getWidth();



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



        mDrawableRect.set(mBorderRect);
        if (!mBorderOverlay && mBorderWidth > 0) {
            mDrawableRect.inset(mBorderWidth - 1.0f, mBorderWidth - 1.0f);
        }
        mDrawableRadius = Math.min(mDrawableRect.height() / 2.0f, mDrawableRect.width() / 2.0f);



        applyColorFilter();
        updateShaderMatrix();
        invalidate();
    }



    private RectF calculateBounds() {
        int availableWidth  = getWidth() - getPaddingLeft() - getPaddingRight();
        int availableHeight = getHeight() - getPaddingTop() - getPaddingBottom();



        int sideLength = Math.min(availableWidth, availableHeight);



        float left = getPaddingLeft() + (availableWidth - sideLength) / 2f;
        float top = getPaddingTop() + (availableHeight - sideLength) / 2f;



        return new RectF(left, top, left + sideLength, top + sideLength);
    }



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



        mBitmapShader.setLocalMatrix(mShaderMatrix);
    }

    @SuppressLint("ClickableViewAccessibility")
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        return inTouchableArea(event.getX(), event.getY()) && super.onTouchEvent(event);
    }



    private boolean inTouchableArea(float x, float y) {
        return Math.pow(x - mBorderRect.centerX(), 2) + Math.pow(y - mBorderRect.centerY(), 2) <= Math.pow(mBorderRadius, 2);
    }
   
    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    private class OutlineProvider extends ViewOutlineProvider {
        @Override
        public void getOutline(View view, Outline outline) {
            Rect bounds = new Rect();
            mBorderRect.roundOut(bounds);
            outline.setRoundRect(bounds, bounds.width() / 2.0f);
        }
    }
}

• 使用的话只需要看一下这三个方法：

//我们可以传入Bitmap, Drawable，Resource以及图像存储路径
@Override
public void setImageBitmap(Bitmap bm) {
    super.setImageBitmap(bm);
    initializeBitmap();
}


@Override
public void setImageDrawable(Drawable drawable) {
    super.setImageDrawable(drawable);
    initializeBitmap();
}


@Override
public void setImageResource(@DrawableRes int resId) {
    super.setImageResource(resId);
    initializeBitmap();
}


@Override
public void setImageURI(Uri uri) {
    super.setImageURI(uri);
    initializeBitmap();
}

• eg:

circleImageView = (CircleImageView)findViewById(R.id.circle_image);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.androidfirst);
circleImageView.setImageBitmap(bitmap);

• 效果图：