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
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
它可以很容易地完成下面的形状。将其作为src添加到图像中。 如果你想删除边界,只需添加你的背景颜色的边界 :-)
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:drawable="@drawable/img_area_one"
android:bottom="5dp"
android:left="5dp"
android:right="5dp"
android:top="5dp" />
<item>
<shape
android:padding="10dp"
android:shape="rectangle">
<corners
android:topLeftRadius="8dp"
android:topRightRadius="8dp"
/>
<stroke
android:width="5dp"
android:color="@color/white" />
</shape>
</item>
</layer-list>
其他回答
对于上面提到的乔治·沃尔特斯二世,我只是把他的答案扩展了一下,以支持不同的圆角。这可以进一步优化(一些目标矩形重叠),但不是很多。
我知道这个线程有点老了,但它是谷歌上关于如何在Android上圆角ImageViews的查询的顶级结果之一。
/**
* Use this method to scale a bitmap and give it specific rounded corners.
* @param context Context object used to ascertain display density.
* @param bitmap The original bitmap that will be scaled and have rounded corners applied to it.
* @param upperLeft Corner radius for upper left.
* @param upperRight Corner radius for upper right.
* @param lowerRight Corner radius for lower right.
* @param lowerLeft Corner radius for lower left.
* @param endWidth Width to which to scale original bitmap.
* @param endHeight Height to which to scale original bitmap.
* @return Scaled bitmap with rounded corners.
*/
public static Bitmap getRoundedCornerBitmap(Context context, Bitmap bitmap, float upperLeft,
float upperRight, float lowerRight, float lowerLeft, int endWidth,
int endHeight) {
float densityMultiplier = context.getResources().getDisplayMetrics().density;
// scale incoming bitmap to appropriate px size given arguments and display dpi
bitmap = Bitmap.createScaledBitmap(bitmap,
Math.round(endWidth * densityMultiplier),
Math.round(endHeight * densityMultiplier), true);
// create empty bitmap for drawing
Bitmap output = Bitmap.createBitmap(
Math.round(endWidth * densityMultiplier),
Math.round(endHeight * densityMultiplier), Config.ARGB_8888);
// get canvas for empty bitmap
Canvas canvas = new Canvas(output);
int width = canvas.getWidth();
int height = canvas.getHeight();
// scale the rounded corners appropriately given dpi
upperLeft *= densityMultiplier;
upperRight *= densityMultiplier;
lowerRight *= densityMultiplier;
lowerLeft *= densityMultiplier;
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setColor(Color.WHITE);
// fill the canvas with transparency
canvas.drawARGB(0, 0, 0, 0);
// draw the rounded corners around the image rect. clockwise, starting in upper left.
canvas.drawCircle(upperLeft, upperLeft, upperLeft, paint);
canvas.drawCircle(width - upperRight, upperRight, upperRight, paint);
canvas.drawCircle(width - lowerRight, height - lowerRight, lowerRight, paint);
canvas.drawCircle(lowerLeft, height - lowerLeft, lowerLeft, paint);
// fill in all the gaps between circles. clockwise, starting at top.
RectF rectT = new RectF(upperLeft, 0, width - upperRight, height / 2);
RectF rectR = new RectF(width / 2, upperRight, width, height - lowerRight);
RectF rectB = new RectF(lowerLeft, height / 2, width - lowerRight, height);
RectF rectL = new RectF(0, upperLeft, width / 2, height - lowerLeft);
canvas.drawRect(rectT, paint);
canvas.drawRect(rectR, paint);
canvas.drawRect(rectB, paint);
canvas.drawRect(rectL, paint);
// set up the rect for the image
Rect imageRect = new Rect(0, 0, width, height);
// set up paint object such that it only paints on Color.WHITE
paint.setXfermode(new AvoidXfermode(Color.WHITE, 255, AvoidXfermode.Mode.TARGET));
// draw resized bitmap onto imageRect in canvas, using paint as configured above
canvas.drawBitmap(bitmap, imageRect, imageRect, paint);
return output;
}
我知道这个问题已经过时了,但这里有另一种更简单的四舍五入图像的方法:
这是一种编程方法。
创造你的空白……
} public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int pixels) { Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.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 = pixels; paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0); paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint); return output;
加载图像,然后设置圆角
imageview1.setImageResource(R.drawable.yourimage);
Bitmap bm = ((android.graphics.drawable.BitmapDrawable) imageview1.getDrawable()).getBitmap();
imageview1.setImageBitmap(getRoundedCornerBitmap(bm, 30));
以30为半径,你会得到这样的结果:
不管我的图像看起来如何,它只是一个放大的小图标
这种纯xml解决方案对我来说已经足够好了。http://www.techrepublic.com/article/pro-tip-round-corners-on-an-android-imageview-with-this-hack/
EDIT
以下是简单的答案:
在/res/drawable文件夹中,创建一个frame.xml文件。在其中,我们定义了一个具有圆角和透明中心的简单矩形。
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">
<solid android:color="#00ffffff" />
<padding android:left="6dp"
android:top="6dp"
android:right="6dp"
android:bottom="6dp" />
<corners android:radius="12dp" />
<stroke android:width="6dp" android:color="#ffffffff" />
</shape>
在你的布局文件中,你添加了一个线性布局,它包含一个标准的ImageView,以及一个嵌套的framayout。FrameLayout使用填充和自定义drawable来提供圆角的错觉。
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:layout_gravity="center"
android:gravity="center"
android:background="#ffffffff">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="6dp"
android:src="@drawable/tr"/>
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="6dp"
android:src="@drawable/tr"/>
<ImageView
android:src="@drawable/frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</FrameLayout>
</LinearLayout>
相当多的答案!
我遵循了一些人也建议的这个例子:http://www.techrepublic.com/article/pro-tip-round-corners-on-an-android-imageview-with-this-hack/
然而,我需要的是一个透明图像后面的彩色圆圈。对于任何有兴趣做同样事情的人…
1)设置FrameLayout的宽度和高度-在我的情况下,图像的大小(50dp)。 2)将带有src = "@drawable/…"的ImageView放在带有图像的ImageView之上。给它一个id,在我的例子中,我叫它iconShape 3) Drawable mask.xml应该是纯色的#ffffffff 4)如果你想在你的代码中动态地改变圆圈的颜色,可以这样做
ImageView iv2 = (ImageView) v.findViewById(R.id.iconShape);
Drawable shape = getResources().getDrawable(R.drawable.mask);
shape.setColorFilter(Color.BLUE, Mode.MULTIPLY);
iv2.setImageDrawable(shape);
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