在Android中,ImageView默认是一个矩形。如何使它成为一个圆角矩形(剪辑我的位图的所有4个角为圆角矩形)在ImageView?


请注意,从2021年起,只需使用ShapeableImageView


当前回答

这里要回答的问题是: 如何在Android中创建一个圆形ImageView ?

public static Bitmap getRoundBitmap(Bitmap bitmap) {

    int min = Math.min(bitmap.getWidth(), bitmap.getHeight());

    Bitmap bitmapRounded = Bitmap.createBitmap(min, min, bitmap.getConfig());

    Canvas canvas = new Canvas(bitmapRounded);
    Paint paint = new Paint();
    paint.setAntiAlias(true);
    paint.setShader(new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));
    canvas.drawRoundRect((new RectF(0.0f, 0.0f, min, min)), min/2, min/2, paint);

    return bitmapRounded;
}

其他回答

您可以尝试这个库- RoundedImageView

它是:

一个快速的ImageView,支持圆角,椭圆形和圆形。CircleImageView的完整超集。

我在我的项目中使用了它,它非常简单。

试试这个

Bitmap finalBitmap;
        if (bitmap.getWidth() != radius || bitmap.getHeight() != radius)
            finalBitmap = Bitmap.createScaledBitmap(bitmap, radius, radius,
                    false);
        else
            finalBitmap = bitmap;
        Bitmap output = Bitmap.createBitmap(finalBitmap.getWidth(),
                finalBitmap.getHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, finalBitmap.getWidth(),
                finalBitmap.getHeight());

        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(Color.parseColor("#BAB399"));
        canvas.drawCircle(finalBitmap.getWidth() / 2 + 0.7f,
                finalBitmap.getHeight() / 2 + 0.7f,
                finalBitmap.getWidth() / 2 + 0.1f, paint);
        paint.setXfermode(new PorterDuffXfermode(
                android.graphics.PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(finalBitmap, rect, rect, paint);

        return output;
    /**
 * Background Async task to load user profile picture from url
 */
private class LoadProfileImage extends AsyncTask<String, Void, RoundedBitmapDrawable> {
    ImageView profileImageView;

    public LoadProfileImage(ImageView profileImageView) {
        this.profileImageView = profileImageView;
    }

    protected RoundedBitmapDrawable doInBackground(String... urls) {
        String photoUrl = urls[0];
        RoundedBitmapDrawable profileRoundedDrawable = null;
        try {
            InputStream inputStream = new java.net.URL(photoUrl).openStream();
            Resources res = getResources();

            profileRoundedDrawable = RoundedBitmapDrawableFactory.create(res, inputStream);
            profileRoundedDrawable.setCircular(true);
        } catch (Exception e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return profileRoundedDrawable;
    }

    protected void onPostExecute(RoundedBitmapDrawable result) {
        profileImageView.setImageDrawable(result);
    }
}

它可以用ShapeableImageView使用ShapeAppearanceOverlay完成:

<com.google.android.material.imageview.ShapeableImageView
    android:id="@+id/avatar"
    android:layout_width="64dp"
    android:layout_height="64dp"
    android:padding="4dp"
    app:shapeAppearance="@style/ShapeAppearanceOverlay.Avatar"/>

其中样式为ShapeAppearanceOverlay。Avatar驻留在res/values/styles.xml中:

<style name="ShapeAppearanceOverlay.Avatar" parent="ShapeAppearance.MaterialComponents.SmallComponent">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSize">50%</item>
</style>

这只需要相等的layout_height和layout_width设置,否则将是一个药丸和没有圆。

你可以在你的布局中只使用ImageView,使用滑动,你可以使用这个方法应用圆角。

首先在你的gradle里写上,

compile 'com.github.bumptech.glide:glide:3.7.0'

对于有圆角的图像,

public void loadImageWithCorners(String url, ImageView view) {
    Glide.with(context)
            .load(url)
            .asBitmap()
            .centerCrop()
            .placeholder(R.color.gray)
            .error(R.color.gray)
            .diskCacheStrategy(DiskCacheStrategy.SOURCE)
            .into(new BitmapImageViewTarget(view) {
                @Override
                protected void setResource(Bitmap resource) {
                    RoundedBitmapDrawable circularBitmapDrawable =
                            RoundedBitmapDrawableFactory.create(context.getResources(), resource);
                    circularBitmapDrawable.setCornerRadius(32.0f); // radius for corners
                    view.setImageDrawable(circularBitmapDrawable);
                }
            });
}

调用方法:

loadImageWithCorners("your url","your imageview");