Android Glide加载圆形图片、圆角图片，部分圆角图片的使用方法
前言Gilde圆形图片/头像Gilde普通圆角图片即四个角都是圆角Gilde对指定角设置圆角前言
通过本文，您可以实现以下效果：
Gilde圆形图片/头像
效果如图，只需要设置requestoption即可，添加circleCropTransform();
具体代码如下：
RequestOptions options = new RequestOptions().placeholder(R.drawable.loading).circleCropTransform();Glide.with(mContext).asBitmap().load(imageUrl).apply(options) .into(myImageView);
Gilde普通圆角图片即四个角都是圆角
效果如图，只需要设置requestoption即可，添加bitmapTransform(new RoundedCorners(20);
// 加载为四个都是圆角的图片 可以设置圆角幅度RequestOptions options = new RequestOptions().placeholder(R.drawable.loading).bitmapTransform(new RoundedCorners(DipPx.dip2px(mContext, 10)));Glide.with(mContext).asBitmap().load(imageUrl).apply(options) .into(myImageView);
此处实现的时候用了一个工具类DipPx中dip2px，将dp值转化为像素值；
该类的具体代码如下：
// 工具类 提供px和dip的相互转化public class DipPx {public static int dip2px(Context context, float dpValue) {final float scale = context.getResources().getDisplayMetrics().density;return (int) (dpValue * scale + 0.5f);}public static int px2dip(Context context, float pxValue) {final float scale = context.getResources().getDisplayMetrics().density;return (int) (pxValue / scale + 0.5f);}}
Gilde对指定角设置圆角
效果如图左上角和右上角为圆角，左下右下为直角，其实现稍微有些复杂;首先需要新建一个class，CornerTransform实现Transformation <Bitmap>，具体代码如下：
public class CornerTransform implements Transformation<Bitmap> {private BitmapPool mBitmapPool;private float radius;private boolean isLeftTop, isRightTop, isLeftBottom, isRightBotoom;/*** 需要设置圆角的部分** @param leftTop左上角* @param rightTop 右上角* @param leftBottom 左下角* @param rightBottom 右下角*/public void setNeedCorner(boolean leftTop, boolean rightTop, boolean leftBottom, boolean rightBottom) {isLeftTop = leftTop;isRightTop = rightTop;isLeftBottom = leftBottom;isRightBotoom = rightBottom;}/*** @param context 上下文* @param radius 圆角幅度*/public CornerTransform(Context context, float radius) {this.mBitmapPool = Glide.get(context).getBitmapPool();this.radius = radius;}@NonNull@Overridepublic Resource<Bitmap> transform(@NonNull Context context, @NonNull Resource<Bitmap> resource, int outWidth, int outHeight) {Bitmap source = resource.get();int finalWidth, finalHeight;//输出目标的宽高或高宽比例float scale;if (outWidth > outHeight) {//如果 输出宽度 > 输出高度 求高宽比scale = (float) outHeight / (float) outWidth;finalWidth = source.getWidth();//固定原图宽度,求最终高度finalHeight = (int) ((float) source.getWidth() * scale);if (finalHeight > source.getHeight()) {//如果 求出的最终高度 > 原图高度 求宽高比scale = (float) outWidth / (float) outHeight;finalHeight = source.getHeight();//固定原图高度,求最终宽度finalWidth = (int) ((float) source.getHeight() * scale);}} else if (outWidth < outHeight) {//如果 输出宽度 < 输出高度 求宽高比scale = (float) outWidth / (float) outHeight;finalHeight = source.getHeight();//固定原图高度,求最终宽度finalWidth = (int) ((float) source.getHeight() * scale);if (finalWidth > source.getWidth()) {//如果 求出的最终宽度 > 原图宽度 求高宽比scale = (float) outHeight / (float) outWidth;finalWidth = source.getWidth();finalHeight = (int) ((float) source.getWidth() * scale);}} else {//如果 输出宽度=输出高度finalHeight = source.getHeight();finalWidth = finalHeight;}//修正圆角this.radius *= (float) finalHeight / (float) outHeight;Bitmap outBitmap = this.mBitmapPool.get(finalWidth, finalHeight, Bitmap.Config.ARGB_8888);if (outBitmap == null) {outBitmap = Bitmap.createBitmap(finalWidth, finalHeight, Bitmap.Config.ARGB_8888);}Canvas canvas = new Canvas(outBitmap);Paint paint = new Paint();//关联画笔绘制的原图bitmapBitmapShader shader = new BitmapShader(source, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);//计算中心位置,进行偏移int width = (source.getWidth() - finalWidth) / 2;int height = (source.getHeight() - finalHeight) / 2;if (width != 0 || height != 0) {Matrix matrix = new Matrix();matrix.setTranslate((float) (-width), (float) (-height));shader.setLocalMatrix(matrix);}paint.setShader(shader);paint.setAntiAlias(true);RectF rectF = new RectF(0.0F, 0.0F, (float) canvas.getWidth(), (float) canvas.getHeight());//先绘制圆角矩形canvas.drawRoundRect(rectF, this.radius, this.radius, paint);//左上角圆角if (!isLeftTop) {canvas.drawRect(0, 0, radius, radius, paint);}//右上角圆角if (!isRightTop) {canvas.drawRect(canvas.getWidth() - radius, 0, canvas.getWidth(), radius, paint);}//左下角圆角if (!isLeftBottom) {canvas.drawRect(0, canvas.getHeight() - radius, radius, canvas.getHeight(), paint);}//右下角圆角if (!isRightBotoom) {canvas.drawRect(canvas.getWidth() - radius, canvas.getHeight() - radius, canvas.getWidth(), canvas.getHeight(), paint);}return BitmapResource.obtain(outBitmap, this.mBitmapPool);}@Overridepublic void updateDiskCacheKey(@NonNull MessageDigest messageDigest) {}}
然后，调用，设置需要圆角的方位即可，具体实现如下：
CornerTransform cornerTransform = new CornerTransform(mContext, DipPx.dip2px(mContext, 10));cornerTransform.setNeedCorner(true, true, false, false);RequestOptions options = new RequestOptions().placeholder(R.drawable.loading).transform(cornerTransform);Glide.with(mContext).asBitmap().load(imageUrl).apply(options) .into(myImageView);
