ImageView scaleType="fitXY" 在 Cardview 内的棒棒糖前设备中不起作用 | Android

Question

我的代码中有 ImageView，它位于 CardView 中，如下所示。我的 ImageView scaleType="fitXY" 在 pre-lollipop 上不起作用 devices.But 在 Lollipop 上看起来更好设备。请看下面的图片。
正如我们在上图中看到的，我想要删除的图像视图周围有白色填充，我希望在 pre-lolipop 和 post lolipop 设备上看起来相似的图像。请帮我解决这个问题。谢谢:)

 <android.support.v7.widget.CardView
                android:layout_width="match_parent"
                android:layout_height="160dp"
                android:layout_marginRight="10dp"
                android:layout_marginTop="6dp"
                app:cardCornerRadius="10dp"
                card_view:cardUseCompatPadding="false"
                >

                <ImageView
                    android:id="@+id/imgChat"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:scaleType="fitXY"
                    />
            </android.support.v7.widget.CardView>

Answer 1

此间隙是 Pre-lollipop 设备中 CardView 内部填充的结果。由于在 Api < 21 中没有对阴影和裁剪的原生支持 CardView 通过后备解决方案重新创建这些效果。现在，如果您定义 cardCornerRadius，在 Pre-lollipop 设备中，CardView 将对您的内容应用内容填充（等于角半径值），以防止您的内容与角重叠。

要禁用此行为，您可以在 XML:

中执行此操作

card_view:cardPreventCornerOverlap="false"

或使用java:

cardView.setPreventCornerOverlap(false)

禁用重叠边角填充。

更新：如果你真的想在棒棒糖之前的设备上达到同样的效果，你可以尝试使用像这样的库自己剪辑你的图像：

https://github.com/vinc3m1/RoundedImageView

，所以当您的内容重叠时 CardView 角会重叠，您将获得与 post-棒棒糖设备相同的外观..

Answer 2

由于 pre-lollipop 设备中没有出现短路问题，我们可以在圆形 Imageview 中自定义 ImageView（就像在 Lollipop 设备中一样）。我们可以检查 OS 并根据它自定义图像视图。

基本上我们可以使用通用图像加载器 this OR Glide image loader this来创建应用程序。

通用图像加载器 提供了默认的 RoundedCorners 来像这样创建 ImageView 的角

 ImageLoader imageLoader = ImageLoader.getInstance();
        imageLoader.init(ImageLoaderConfiguration.createDefault(MainActivity.this));
        DisplayImageOptions options = new DisplayImageOptions.Builder()
                .displayer(new RoundedBitmapDisplayer(20))/// RoundedBitmapDisplayer IS THE CLASS BY  WHICH , WE CAN CREATE THE ROUNDED CORNER OF THE IMAGEVIEW
                .cacheInMemory(true)
                .cacheOnDisk(true)
                .build();
        imageLoader.displayImage("http://thedeveloperworldisyours.com/wp-content/uploads/scareface.jpeg", YOUR_IMAGEVIEW,options);

在Glide image loader中，我们需要创建自定义class来创建Imageview的圆弧，在此您会发现自定义圆角 class 围绕 ImageView

创建圆弧

Glide.with(this)
                .load("http://thedeveloperworldisyours.com/wp-content/uploads/scareface.jpeg")
                .bitmapTransform(new RoundedCornersTransformation( MainActivity.this,15, 2)) ///RoundedCornersTransformation IS THE CLASS, WHICH YOU NEED TO COPY INSIDE YOURS PROJECT, PLEASE FIND THIS CLASS ON ABOVE LINK AND I AM ALSO PROVIDING THE CLASS FOR IT
                .into(YOUR_IMAGEVIEW);

为了在 glide 中创建圆角，我们需要在我们的项目中复制下面的 class，我从这个

中得到了这个 class

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Shader;

import com.bumptech.glide.Glide;
import com.bumptech.glide.load.Transformation;
import com.bumptech.glide.load.engine.Resource;
import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool;
import com.bumptech.glide.load.resource.bitmap.BitmapResource;

/**
 * Created by javiergonzalezcabezas on 2/4/16.
 */
public class RoundedCornersTransformation implements Transformation<Bitmap> {

    public enum CornerType {
        ALL,
        TOP_LEFT, TOP_RIGHT, BOTTOM_LEFT, BOTTOM_RIGHT,
        TOP, BOTTOM, LEFT, RIGHT,
        OTHER_TOP_LEFT, OTHER_TOP_RIGHT, OTHER_BOTTOM_LEFT, OTHER_BOTTOM_RIGHT,
        DIAGONAL_FROM_TOP_LEFT, DIAGONAL_FROM_TOP_RIGHT
    }

    private BitmapPool mBitmapPool;
    private int mRadius;
    private int mDiameter;
    private int mMargin;
    private CornerType mCornerType;

    public RoundedCornersTransformation(Context context, int radius, int margin) {
        this(context, radius, margin, CornerType.ALL);
    }

    public RoundedCornersTransformation(BitmapPool pool, int radius, int margin) {
        this(pool, radius, margin, CornerType.ALL);
    }

    public RoundedCornersTransformation(Context context, int radius, int margin,
                                        CornerType cornerType) {
        this(Glide.get(context).getBitmapPool(), radius, margin, cornerType);
    }

    public RoundedCornersTransformation(BitmapPool pool, int radius, int margin,
                                        CornerType cornerType) {
        mBitmapPool = pool;
        mRadius = radius;
        mDiameter = mRadius * 2;
        mMargin = margin;
        mCornerType = cornerType;
    }

    @Override
    public Resource<Bitmap> transform(Resource<Bitmap> resource, int outWidth, int outHeight) {
        Bitmap source = resource.get();

        int width = source.getWidth();
        int height = source.getHeight();

        Bitmap bitmap = mBitmapPool.get(width, height, Bitmap.Config.ARGB_8888);
        if (bitmap == null) {
            bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        }

        Canvas canvas = new Canvas(bitmap);
        Paint paint = new Paint();
        paint.setAntiAlias(true);
        paint.setShader(new BitmapShader(source, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));
        drawRoundRect(canvas, paint, width, height);
        return BitmapResource.obtain(bitmap, mBitmapPool);
    }

    private void drawRoundRect(Canvas canvas, Paint paint, float width, float height) {
        float right = width - mMargin;
        float bottom = height - mMargin;

        switch (mCornerType) {
            case ALL:
                canvas.drawRoundRect(new RectF(mMargin, mMargin, right, bottom), mRadius, mRadius, paint);
                break;
            case TOP_LEFT:
                drawTopLeftRoundRect(canvas, paint, right, bottom);
                break;
            case TOP_RIGHT:
                drawTopRightRoundRect(canvas, paint, right, bottom);
                break;
            case BOTTOM_LEFT:
                drawBottomLeftRoundRect(canvas, paint, right, bottom);
                break;
            case BOTTOM_RIGHT:
                drawBottomRightRoundRect(canvas, paint, right, bottom);
                break;
            case TOP:
                drawTopRoundRect(canvas, paint, right, bottom);
                break;
            case BOTTOM:
                drawBottomRoundRect(canvas, paint, right, bottom);
                break;
            case LEFT:
                drawLeftRoundRect(canvas, paint, right, bottom);
                break;
            case RIGHT:
                drawRightRoundRect(canvas, paint, right, bottom);
                break;
            case OTHER_TOP_LEFT:
                drawOtherTopLeftRoundRect(canvas, paint, right, bottom);
                break;
            case OTHER_TOP_RIGHT:
                drawOtherTopRightRoundRect(canvas, paint, right, bottom);
                break;
            case OTHER_BOTTOM_LEFT:
                drawOtherBottomLeftRoundRect(canvas, paint, right, bottom);
                break;
            case OTHER_BOTTOM_RIGHT:
                drawOtherBottomRightRoundRect(canvas, paint, right, bottom);
                break;
            case DIAGONAL_FROM_TOP_LEFT:
                drawDiagonalFromTopLeftRoundRect(canvas, paint, right, bottom);
                break;
            case DIAGONAL_FROM_TOP_RIGHT:
                drawDiagonalFromTopRightRoundRect(canvas, paint, right, bottom);
                break;
            default:
                canvas.drawRoundRect(new RectF(mMargin, mMargin, right, bottom), mRadius, mRadius, paint);
                break;
        }
    }

    private void drawTopLeftRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(mMargin, mMargin, mMargin + mDiameter, mMargin + mDiameter),
                mRadius, mRadius, paint);
        canvas.drawRect(new RectF(mMargin, mMargin + mRadius, mMargin + mRadius, bottom), paint);
        canvas.drawRect(new RectF(mMargin + mRadius, mMargin, right, bottom), paint);
    }

    private void drawTopRightRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(right - mDiameter, mMargin, right, mMargin + mDiameter), mRadius,
                mRadius, paint);
        canvas.drawRect(new RectF(mMargin, mMargin, right - mRadius, bottom), paint);
        canvas.drawRect(new RectF(right - mRadius, mMargin + mRadius, right, bottom), paint);
    }

    private void drawBottomLeftRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(mMargin, bottom - mDiameter, mMargin + mDiameter, bottom),
                mRadius, mRadius, paint);
        canvas.drawRect(new RectF(mMargin, mMargin, mMargin + mDiameter, bottom - mRadius), paint);
        canvas.drawRect(new RectF(mMargin + mRadius, mMargin, right, bottom), paint);
    }

    private void drawBottomRightRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(right - mDiameter, bottom - mDiameter, right, bottom), mRadius,
                mRadius, paint);
        canvas.drawRect(new RectF(mMargin, mMargin, right - mRadius, bottom), paint);
        canvas.drawRect(new RectF(right - mRadius, mMargin, right, bottom - mRadius), paint);
    }

    private void drawTopRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(mMargin, mMargin, right, mMargin + mDiameter), mRadius, mRadius,
                paint);
        canvas.drawRect(new RectF(mMargin, mMargin + mRadius, right, bottom), paint);
    }

    private void drawBottomRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(mMargin, bottom - mDiameter, right, bottom), mRadius, mRadius,
                paint);
        canvas.drawRect(new RectF(mMargin, mMargin, right, bottom - mRadius), paint);
    }

    private void drawLeftRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(mMargin, mMargin, mMargin + mDiameter, bottom), mRadius, mRadius,
                paint);
        canvas.drawRect(new RectF(mMargin + mRadius, mMargin, right, bottom), paint);
    }

    private void drawRightRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(right - mDiameter, mMargin, right, bottom), mRadius, mRadius,
                paint);
        canvas.drawRect(new RectF(mMargin, mMargin, right - mRadius, bottom), paint);
    }

    private void drawOtherTopLeftRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(mMargin, bottom - mDiameter, right, bottom), mRadius, mRadius,
                paint);
        canvas.drawRoundRect(new RectF(right - mDiameter, mMargin, right, bottom), mRadius, mRadius,
                paint);
        canvas.drawRect(new RectF(mMargin, mMargin, right - mRadius, bottom - mRadius), paint);
    }

    private void drawOtherTopRightRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(mMargin, mMargin, mMargin + mDiameter, bottom), mRadius, mRadius,
                paint);
        canvas.drawRoundRect(new RectF(mMargin, bottom - mDiameter, right, bottom), mRadius, mRadius,
                paint);
        canvas.drawRect(new RectF(mMargin + mRadius, mMargin, right, bottom - mRadius), paint);
    }

    private void drawOtherBottomLeftRoundRect(Canvas canvas, Paint paint, float right, float bottom) {
        canvas.drawRoundRect(new RectF(mMargin, mMargin, right, mMargin + mDiameter), mRadius, mRadius,
                paint);
        canvas.drawRoundRect(new RectF(right - mDiameter, mMargin, right, bottom), mRadius, mRadius,
                paint);
        canvas.drawRect(new RectF(mMargin, mMargin + mRadius, right - mRadius, bottom), paint);
    }

    private void drawOtherBottomRightRoundRect(Canvas canvas, Paint paint, float right,
                                               float bottom) {
        canvas.drawRoundRect(new RectF(mMargin, mMargin, right, mMargin + mDiameter), mRadius, mRadius,
                paint);
        canvas.drawRoundRect(new RectF(mMargin, mMargin, mMargin + mDiameter, bottom), mRadius, mRadius,
                paint);
        canvas.drawRect(new RectF(mMargin + mRadius, mMargin + mRadius, right, bottom), paint);
    }

    private void drawDiagonalFromTopLeftRoundRect(Canvas canvas, Paint paint, float right,
                                                  float bottom) {
        canvas.drawRoundRect(new RectF(mMargin, mMargin, mMargin + mDiameter, mMargin + mDiameter),
                mRadius, mRadius, paint);
        canvas.drawRoundRect(new RectF(right - mDiameter, bottom - mDiameter, right, bottom), mRadius,
                mRadius, paint);
        canvas.drawRect(new RectF(mMargin, mMargin + mRadius, right - mDiameter, bottom), paint);
        canvas.drawRect(new RectF(mMargin + mDiameter, mMargin, right, bottom - mRadius), paint);
    }

    private void drawDiagonalFromTopRightRoundRect(Canvas canvas, Paint paint, float right,
                                                   float bottom) {
        canvas.drawRoundRect(new RectF(right - mDiameter, mMargin, right, mMargin + mDiameter), mRadius,
                mRadius, paint);
        canvas.drawRoundRect(new RectF(mMargin, bottom - mDiameter, mMargin + mDiameter, bottom),
                mRadius, mRadius, paint);
        canvas.drawRect(new RectF(mMargin, mMargin, right - mRadius, bottom - mRadius), paint);
        canvas.drawRect(new RectF(mMargin + mRadius, mMargin + mRadius, right, bottom), paint);
    }

    @Override public String getId() {
        return "RoundedTransformation(radius=" + mRadius + ", margin=" + mMargin + ", diameter="
                + mDiameter + ", cornerType=" + mCornerType.name() + ")";
    }
}

ImageView scaleType="fitXY" 在 Cardview 内的棒棒糖前设备中不起作用 | Android

ImageView scaleType="fitXY" is not working in pre-lollipop device inside the Cardview | Android

android

android-imageview

android-4.4-kitkat

android-cardview

android-5.0-lollipop