android 方式实现imageview圆角

自定义imageview

public class RoundImageView extends ImageView {    /**     * 图片的类型，圆形or圆角     */    private int type;    public static final int TYPE_CIRCLE = 0;    public static final int TYPE_ROUND = 1;    /**     * 圆角大小的默认值     */    private static final int BODER_RADIUS_DEFAULT = 10;    /**     * 圆角的大小     */    private int mBorderRadius;    /**     * 绘图的Paint     */    private Paint mBitmapPaint;    /**     * 圆角的半径     */    private int mRadius;    /**     * 3x3 矩阵，主要用于缩小放大     */    private Matrix mMatrix;    /**     * 渲染图像，使用图像为绘制图形着色     */    private BitmapShader mBitmapShader;    /**     * view的宽度     */    private int mWidth;    private RectF mRoundRect;    /**     * 构造函数:获取自定义属性     */    public RoundImageView(Context context, AttributeSet attrs) {        super(context, attrs);        mMatrix = new Matrix();        mBitmapPaint = new Paint();        mBitmapPaint.setAntiAlias(true);        TypedArray a = context.obtainStyledAttributes(attrs,                R.styleable.RoundImageView);        mBorderRadius = a.getDimensionPixelSize(                R.styleable.RoundImageView_borderRadius, (int) TypedValue                        .applyDimension(TypedValue.COMPLEX_UNIT_DIP,                                BODER_RADIUS_DEFAULT, getResources()                                        .getDisplayMetrics()));// 默认为10dp        type = a.getInt(R.styleable.RoundImageView_type, TYPE_CIRCLE);// 默认为Circle        a.recycle();    }    /**     * 关于view的宽高:主要用于当设置类型为圆形时，我们强制让view的宽和高一致     */    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        Log.e("TAG", "onMeasure");        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        /**         * 如果类型是圆形，则强制改变view的宽高一致，以小值为准;如果是圆角则不用管宽高问题         */        if (type == TYPE_CIRCLE) {            mWidth = Math.min(getMeasuredWidth(), getMeasuredHeight());            mRadius = mWidth / 2;            setMeasuredDimension(mWidth, mWidth);        }    }    /**     * 1. 设置BitmapShader     * 2. 绘制     */    @Override    protected void onDraw(Canvas canvas) {        if (getDrawable() == null) {            return;        }        setUpShader();        if (type == TYPE_ROUND) {            canvas.drawRoundRect(mRoundRect, mBorderRadius, mBorderRadius,                    mBitmapPaint);        } else {            canvas.drawCircle(mRadius, mRadius, mRadius, mBitmapPaint);            // drawSomeThing(canvas);        }    }    @Override    protected void onSizeChanged(int w, int h, int oldw, int oldh) {        super.onSizeChanged(w, h, oldw, oldh);        // 圆角图片的范围        if (type == TYPE_ROUND)            mRoundRect = new RectF(0, 0, getWidth(), getHeight());    }    /**     * 初始化BitmapShader//给paint附加一个具有某种魔力(缩放)的shader     * 1. drawable转化为我们的bitmap     * 2. 设置shader 的mode     * 3. 设置scale: 因为最终缩放完成的图片一定要大于我们的view的区域     * 4. scale设置给matrix     * 5. matrix设置给shader     * 6. shader设置给paint     */    private void setUpShader() {        Drawable drawable = getDrawable();        if (drawable == null) {            return;        }        Bitmap bmp = drawableToBitamp(drawable);        // 将bmp作为着色器，就是在指定区域内绘制bmp;此构造方法用的是拉伸mode: clamp        mBitmapShader = new BitmapShader(bmp, CLAMP, CLAMP);        float scale = 1.0f;        if (type == TYPE_CIRCLE) {            // 拿到bitmap宽或高的小值//我们需要画正方形            int bSize = Math.min(bmp.getWidth(), bmp.getHeight());            scale = mWidth * 1.0f / bSize;        } else if (type == TYPE_ROUND) {            // 如果图片的宽或者高与view的宽高不匹配，计算出需要缩放的比例；缩放后的图片的宽高，一定要大于我们view的宽高；所以我们这里取大值；//view的宽度/bitmap的宽度=缩放倍数            scale = Math.max(getWidth() * 1.0f / bmp.getWidth(), getHeight()                    * 1.0f / bmp.getHeight());        }        // shader的变换矩阵，我们这里主要用于放大或者缩小        mMatrix.setScale(scale, scale);        // 设置变换矩阵        mBitmapShader.setLocalMatrix(mMatrix);        // 先给paint设置shader;然后画笔会有所不同哦,例如        mBitmapPaint.setShader(mBitmapShader);    }    /**     * drawable转bitmap     *     * @param drawable     * @return     */    private Bitmap drawableToBitamp(Drawable drawable) {        if (drawable instanceof BitmapDrawable) {            BitmapDrawable bd = (BitmapDrawable) drawable;            return bd.getBitmap();        }        //以下为drawable转bitmap的通用方法        int w = drawable.getIntrinsicWidth();        int h = drawable.getIntrinsicHeight();        Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);        Canvas canvas = new Canvas(bitmap);        drawable.setBounds(0, 0, w, h);        drawable.draw(canvas);        return bitmap;    }    /**     * 添加一个方法     * bitmap转drawable     */    private Drawable bitmapToDrawable(Bitmap bitmap) {        Drawable drawable = new BitmapDrawable(null, bitmap);        return drawable;    }    //状态存储与恢复    private static final String STATE_INSTANCE = "state_instance";    private static final String STATE_TYPE = "state_type";    private static final String STATE_BORDER_RADIUS = "state_border_radius";    @Override    protected Parcelable onSaveInstanceState() {        Bundle bundle = new Bundle();        bundle.putParcelable(STATE_INSTANCE, super.onSaveInstanceState());        bundle.putInt(STATE_TYPE, type);        bundle.putInt(STATE_BORDER_RADIUS, mBorderRadius);        return bundle;    }    @Override    protected void onRestoreInstanceState(Parcelable state) {        if (state instanceof Bundle) {            Bundle bundle = (Bundle) state;            super.onRestoreInstanceState(((Bundle) state)                    .getParcelable(STATE_INSTANCE));            this.type = bundle.getInt(STATE_TYPE);            this.mBorderRadius = bundle.getInt(STATE_BORDER_RADIUS);        } else {            super.onRestoreInstanceState(state);        }    }    /**     * 动态修改圆角大小     * */    public void setBorderRadius(int borderRadius) {        int pxVal = dp2px(borderRadius);        if (this.mBorderRadius != pxVal) {            this.mBorderRadius = pxVal;            invalidate();        }    }    /**     * 动态设置type     * */    public void setType(int type) {        if (this.type != type) {            this.type = type;            if (this.type != TYPE_ROUND && this.type != TYPE_CIRCLE) {                this.type = TYPE_CIRCLE;            }            requestLayout();        }    }    private int dp2px(int dpVal) {        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,                dpVal, getResources().getDisplayMetrics());    }

自定义控件属性

使用方式

<?xml version="1.0" encoding="utf-8"?>

按照正常的实例化,就可以了成功了,优点就是没有内存溢出了

参考文章鸿洋显示效果和鸿洋的一样,不在显示了

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