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

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);
    }
}

其他回答

您应该扩展ImageView并绘制自己的圆角矩形。

如果你想在图像周围添加一个框架,你也可以在布局中将圆形框架叠加在图像视图的顶部。

例如,通过使用FrameLayout将帧叠加到原始图像上。FrameLayout的第一个元素将是你想要显示的图像。然后添加另一个ImageView与框架。第二个ImageView将显示在原始ImageView的顶部,因此Android将在原始ImageView上方绘制它的内容。

对我来说,下面的解决方案似乎是最优雅的:

ImageView roundedImageView = new ImageView (getContext());
roundedImageView.setClipToOutline(true);
Bitmap bitmap = AppUtil.decodeSampledBitmapFromResource(new File(valueListItemsView.getImagePath()), width, height);
roundedImageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
roundedImageView.setImageBitmap(bitmap);
roundedImageView.setBackgroundResource(R.drawable.rounded_corner);

而可绘制的rounded_corner.xml的代码是:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@color/colorAccent" />
    <corners android:radius="24dp" />
</shape>

芬兰湾的科特林版:

@GlideExtension
object GamersGeekGlideExtension {

    @NonNull
    @JvmStatic
    @GlideOption
    fun roundedCorners(options: BaseRequestOptions<*>, context: Context, cornerRadius: Int): BaseRequestOptions<*> {
        val px =
            (cornerRadius * (context.resources.displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT)).roundToInt()
        return options.transforms(RoundedCorners(px))
    }
}

注意:Glide扩展现在需要BaseRequestOptions而不是RequestOptions。此外,它与@Sir Codesalot答案在kotlin中转换的函数相同。

我使用了一个自定义视图,我在其他视图的顶部布局,它只是画了4个小倒角,颜色与背景相同。

优点:

不分配位图。 适用于任何你想要应用圆角的视图。 适用于所有API级别;)

代码:

public class RoundedCornersView extends View {
    private float mRadius;
    private int mColor = Color.WHITE;
    private Paint mPaint;
    private Path mPath;

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

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

        TypedArray a = context.getTheme().obtainStyledAttributes(
                attrs,
                R.styleable.RoundedCornersView,
                0, 0);

        try {
            setRadius(a.getDimension(R.styleable.RoundedCornersView_radius, 0));
            setColor(a.getColor(R.styleable.RoundedCornersView_cornersColor, Color.WHITE));
        } finally {
            a.recycle();
        }
    }

    private void init() {
        setColor(mColor);
        setRadius(mRadius);
    }

    private void setColor(int color) {
        mColor = color;
        mPaint = new Paint();
        mPaint.setColor(mColor);
        mPaint.setStyle(Paint.Style.FILL);
        mPaint.setAntiAlias(true);

        invalidate();
    }

    private void setRadius(float radius) {
        mRadius = radius;
        RectF r = new RectF(0, 0, 2 * mRadius, 2 * mRadius);
        mPath = new Path();
        mPath.moveTo(0,0);
        mPath.lineTo(0, mRadius);
        mPath.arcTo(r, 180, 90);
        mPath.lineTo(0,0);
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {

        /*This just draws 4 little inverted corners */

        int w = getWidth();
        int h = getHeight();
        canvas.drawPath(mPath, mPaint);
        canvas.save();
        canvas.translate(w, 0);
        canvas.rotate(90);
        canvas.drawPath(mPath, mPaint);
        canvas.restore();
        canvas.save();
        canvas.translate(w, h);
        canvas.rotate(180);
        canvas.drawPath(mPath, mPaint);
        canvas.restore();
        canvas.translate(0, h);
        canvas.rotate(270);
        canvas.drawPath(mPath, mPaint);
    }
}

科特林

import android.graphics.BitmapFactory
import android.os.Bundle
import android.support.v4.graphics.drawable.RoundedBitmapDrawableFactory
import kotlinx.android.synthetic.main.activity_main.*

val bitmap = BitmapFactory.decodeResource(resources, R.drawable.myImage)
val rounded = RoundedBitmapDrawableFactory.create(resources, bitmap)
rounded.cornerRadius = 20f
profileImageView.setImageDrawable(rounded)

为了使ImageView成为圆形,我们可以改变拐角半径:

rounded.isCircular = true