ImageView圆角

最简单的方法:

在使用形状xml drawables玩了很多之后,终于找到了圆形/圆形ImageView的工作解决方案,而不使用任何库或Java代码.

在应用程序的res/drawable /文件夹下创建一个xml文件rounded_fg.xml.rounded_fg.xml的内容如下,

<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:innerRadiusRatio="2"
    android:shape="ring"
    android:thicknessRatio="1"
    android:useLevel="false">
    <gradient
        android:type="radial"
        android:gradientRadius="8dp"
        android:endColor="@color/white"
       />
</shape>

您可以将endColor与ImageView容器布局背景匹配,gradientRadius可以是根据您的要求(<= 36dp)的任何值.

现在将此drawable用作imageview的前景,如下所示,

 <ImageView
     android:layout_
     android:layout_ 
     android:foreground="@drawable/rounded_fg" />

适用于方形图像和/或图像视图.

方形图像/ ImageView:

矩形图像/ ImageView:

前景应用于按钮:

新的答案 使用Glide库.Google也推荐使用此库.请参见如何使用Glide库对图像进行舍入？

旧答案 只需在cardViewad中添加该图像并在0dp上设置cardView的高程...就可以了(在我的例子中是viewPager带图像的 - 只需替换为viewPagera ImageView):

<android.support.v7.widget.CardView
    android:layout_
    android:layout_
    app:cardElevation="0dp">

    <android.support.v4.view.ViewPager
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/viewPager"
        android:layout_
        android:layout_ />

</android.support.v7.widget.CardView>

我使用通用图像加载程序库来下载和舍入图像的角落,它对我有用.

ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(thisContext)
            // You can pass your own memory cache implementation
           .discCacheFileNameGenerator(new HashCodeFileNameGenerator())
           .build();

DisplayImageOptions options = new DisplayImageOptions.Builder()
            .displayer(new RoundedBitmapDisplayer(10)) //rounded corner bitmap
            .cacheInMemory(true)
            .cacheOnDisc(true)
            .build();

ImageLoader imageLoader = ImageLoader.getInstance();
imageLoader.init(config);
imageLoader.displayImage(image_url,image_view, options );

您应该使用RoundedCornersTransformation从这个库,并创建一个圆形ImageView.

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.squareup.picasso.Transformation;

public class RoundedCornersTransformation implements Transformation {

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

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

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

    @Override public Bitmap transform(Bitmap source) {
        int width = source.getWidth();
        int height = source.getHeight();
        Bitmap 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);
        source.recycle();
        return bitmap;
    }

    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 key() {
        return "RoundedTransformation(radius=" + mRadius + ", margin=" + mMargin + ", diameter=" + mDiameter + ", cornerType=" + mCornerType.name() + ")";
    }
}

你可以像这样用XML做

<stroke android:
        android:color="#ff000000"/>

<padding android:left="1dp"
         android:top="1dp"
         android:right="1dp"
         android:bottom="1dp"/> 

<corners android:radius="30px"/> 

并且实际上你可以创建圆角位图并在ImageView中设置.

public static Bitmap getRoundedCornerBitmap(Bitmap bitmap) {
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
    bitmap.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(output);

final int color = 0xff424242;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);
final float roundPx = 12;

paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);

return output;
}

对于通用懒惰装载机,您也可以使用此扫描仪.

DisplayImageOptions options = new DisplayImageOptions.Builder()
        .displayer(new RoundedBitmapDisplayer(25)) // default
        .build();