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
我的ImageView圆角小部件的实现，(下||上)大小图像到所需的尺寸。它利用了CaspNZ的代码形式。
public class ImageViewRounded extends ImageView {
public ImageViewRounded(Context context) {
super(context);
}
public ImageViewRounded(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ImageViewRounded(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onDraw(Canvas canvas) {
BitmapDrawable drawable = (BitmapDrawable) getDrawable();
if (drawable == null) {
return;
}
if (getWidth() == 0 || getHeight() == 0) {
return;
}
Bitmap fullSizeBitmap = drawable.getBitmap();
int scaledWidth = getMeasuredWidth();
int scaledHeight = getMeasuredHeight();
Bitmap mScaledBitmap;
if (scaledWidth == fullSizeBitmap.getWidth() && scaledHeight == fullSizeBitmap.getHeight()) {
mScaledBitmap = fullSizeBitmap;
} else {
mScaledBitmap = Bitmap.createScaledBitmap(fullSizeBitmap, scaledWidth, scaledHeight, true /* filter */);
}
Bitmap roundBitmap = ImageUtilities.getRoundedCornerBitmap(getContext(), mScaledBitmap, 5, scaledWidth, scaledHeight,
false, false, false, false);
canvas.drawBitmap(roundBitmap, 0, 0, null);
}
}
其他回答
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);
}
}
我认为最简单的解决方法是这样的:-
步骤1 -创建一个形状绘图文件如下所示
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid android:color="@color/white" />
<corners android:radius="@dimen/dimen_10dp" />
<stroke
android:width="1dp"
android:color="@color/white" />
</shape>
步骤2 -在代码中使用上述绘图。
Drawable drawable = ContextCompat.getDrawable(mActivity, R.drawable.photos_round_shape);
drawable.mutate().setColorFilter(randomColor, PorterDuff.Mode.SRC_ATOP);
imageView.setBackground(drawable);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
imageView.setClipToOutline(true);
}
Glide.with(mContext)
.setDefaultRequestOptions(getNoAnimationOptions())
.load(url)
.into(imageView);
希望这能有所帮助。
罗曼盖伊就在那里。
缩小版如下。
Bitmap bitmap = ((BitmapDrawable) getResources().getDrawable(R.drawable.image)).getBitmap();
Bitmap bitmapRounded = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), 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, bitmap.getWidth(), bitmap.getHeight())), 10, 10, paint);
imageView.setImageBitmap(bitmapRounded);
多亏了melanke，你可以使用一个自定义类并创建一个自定义循环ImageView。
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
public class MLRoundedImageView extends android.support.v7.widget.AppCompatImageView {
public MLRoundedImageView(Context context) {
super(context);
}
public MLRoundedImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MLRoundedImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onDraw(Canvas canvas) {
Drawable drawable = getDrawable();
if (drawable == null) {
return;
}
if (getWidth() == 0 || getHeight() == 0) {
return;
}
Bitmap b = ((BitmapDrawable) drawable).getBitmap();
Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);
int w = getWidth(), h = getHeight();
Bitmap roundBitmap = getCroppedBitmap(bitmap, w);
canvas.drawBitmap(roundBitmap, 0, 0, null);
}
public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
Bitmap sbmp;
if (bmp.getWidth() != radius || bmp.getHeight() != radius) {
float smallest = Math.min(bmp.getWidth(), bmp.getHeight());
float factor = smallest / radius;
sbmp = Bitmap.createScaledBitmap(bmp, (int)(bmp.getWidth() / factor), (int)(bmp.getHeight() / factor), false);
} else {
sbmp = bmp;
}
Bitmap output = Bitmap.createBitmap(radius, radius,
Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xffa19774;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, radius, radius);
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
paint.setDither(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(Color.parseColor("#BAB399"));
canvas.drawCircle(radius / 2 + 0.7f,
radius / 2 + 0.7f, radius / 2 + 0.1f, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(sbmp, rect, rect, paint);
return output;
}
}
然后在XML中使用它:
<your.package.name.MLRoundedImageView
..
/>
源
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>
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