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

这里使用ImageLoader

创建DisplayImageOptions:

DisplayImageOptions options = new DisplayImageOptions.Builder()
    // this will make circle, pass the width of image 
    .displayer(new RoundedBitmapDisplayer(getResources().getDimensionPixelSize(R.dimen.image_dimen_menu))) 
    .cacheOnDisc(true)
    .build();

imageLoader.displayImage(url_for_image,ImageView,options);

或者你也可以从Square上使用毕加索图书馆。

Picasso.with(mContext)
    .load(com.app.utility.Constants.BASE_URL+b.image)
    .placeholder(R.drawable.profile)
    .error(R.drawable.profile)
    .transform(new RoundedTransformation(50, 4))
    .resizeDimen(R.dimen.list_detail_image_size, R.dimen.list_detail_image_size)
    .centerCrop()
    .into(v.im_user);

你可以在这里下载RoundedTransformation文件 在这里

其他回答

我已经通过自定义ImageView完成:

public class RoundRectCornerImageView extends ImageView {

    private float radius = 18.0f;
    private Path path;
    private RectF rect;

    public RoundRectCornerImageView(Context context) {
        super(context);
        init();
    }

    public RoundRectCornerImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public RoundRectCornerImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    private void init() {
        path = new Path();

    }

    @Override
    protected void onDraw(Canvas canvas) {
        rect = new RectF(0, 0, this.getWidth(), this.getHeight());
        path.addRoundRect(rect, radius, radius, Path.Direction.CW);
        canvas.clipPath(path);
        super.onDraw(canvas);
    }
}

使用方法:

<com.mypackage.RoundRectCornerImageView
     android:id="@+id/imageView"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:background="@drawable/image"
     android:scaleType="fitXY" />

输出:

希望这对你有所帮助。

如果你们中有人面临这个问题

大多数情况下,你使用的是Android Studio。由于图像大小的调整和所有在Android工作室,你可能会遇到这个问题。解决这个问题的一个简单方法是减小drawCircle()中的圆的半径。在我的情况下,我使用这个修复

使用画布。drawCircle(100,100,90, paint);而不是帆布。drawCircle(100,100,100, paint);这绝对能解决你的问题。

下面是最终编辑的代码:-

  public class Profile extends ActionBarActivity {


    TextView username;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.profile);


        username= (TextView) findViewById(R.id.txt);

        String recievedusername=getIntent().getExtras().getString("toname");
        username.setText(recievedusername);


        Bitmap bm = BitmapFactory.decodeResource(getResources(),
                R.mipmap.gomez);

        Bitmap resizedBitmap = Bitmap.createScaledBitmap(bm, 200,200, false);
        Bitmap conv_bm=getCircleBitmap(resizedBitmap,100);
        // set circle bitmap
        ImageView mImage = (ImageView) findViewById(R.id.profile_image);
        mImage.setImageBitmap(conv_bm);
        // TODO Auto-generated method stub
    }
    private Bitmap getCircleBitmap(Bitmap bitmap , int pixels) {
        final Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
                bitmap.getHeight(), Bitmap.Config.ARGB_8888);
        final 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);
        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        canvas.drawCircle(100,100, 90, paint);
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);
        bitmap.recycle();
        return output;
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.menu_apploud, menu);
        return super.onCreateOptionsMenu(menu);
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        //noinspection SimplifiableIfStatement
        if (id == R.id.action_addnew) {
            Intent i;
            i=new Intent(Profile.this,ApplaudSomeone.class);
            startActivity(i);
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

因为所有的答案对我来说都太复杂了,只是为了圆角,我想到了另一个解决方案,我认为值得分享,只是XML,以防你在图像周围有一些空间:

创建一个带有透明内容的带边框的形状,如下所示:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <corners 
        android:radius="30dp" />
    <stroke 
        android:color="#ffffffff"
        android:width="10dp" />
</shape> 

然后在RelativeLayout中,你可以先放置你的图像,然后在相同的位置上面的形状与另一个ImageView。封面形状的大小应与边框宽度相等。注意,要取一个较大的角半径,因为外半径已被定义,但内半径是覆盖你的图像。

希望它也能帮助到别人。

根据CQM请求编辑相关布局示例:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <ImageView
        android:id="@+id/imageToShow"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/imgCorners"
        android:layout_alignLeft="@+id/imgCorners"
        android:layout_alignRight="@+id/imgCorners"
        android:layout_alignTop="@+id/imgCorners"
        android:background="#ffffff"
        android:contentDescription="@string/desc"
        android:padding="5dp"
        android:scaleType="centerCrop" />

    <ImageView
        android:id="@+id/imgCorners"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:adjustViewBounds="true"
        android:contentDescription="@string/desc"
        android:src="@drawable/corners_white" />

</RelativeLayout>

另一种简单的方法是使用一个带有角半径的CardView和一个ImageView在里面:

  <androidx.cardview.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:cardCornerRadius="8dp"
            android:layout_margin="5dp"
            android:elevation="10dp">

            <ImageView
                android:id="@+id/roundedImageView"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:src="@drawable/image"
                android:background="@color/white"
                android:scaleType="centerCrop"
                />
        </androidx.cardview.widget.CardView>

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;