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
/**
* 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);
}
}
其他回答
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);
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");
下面是一个覆盖imageView的简单示例,然后你也可以在布局设计器中使用它来预览。
public class RoundedImageView extends ImageView {
public RoundedImageView(Context context) {
super(context);
}
public RoundedImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public RoundedImageView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public RoundedImageView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
@Override
public void setImageDrawable(Drawable drawable) {
float radius = 0.1f;
Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
RoundedBitmapDrawable rid = RoundedBitmapDrawableFactory.create(getResources(), bitmap);
rid.setCornerRadius(bitmap.getWidth() * radius);
super.setImageDrawable(rid);
}
}
这是为了快速解决问题。半径用于所有角落,并基于位图宽度的百分比。
我只是覆盖了setImageDrawable,并使用支持v4方法绘制圆角位图。
用法:
<com.example.widgets.RoundedImageView
android:layout_width="39dp"
android:layout_height="39dp"
android:src="@drawable/your_drawable" />
使用imageView和自定义imageView预览:
虽然前两个答案是可行的,但我希望再多描述一点。 比如说,ImageView所在的地方有一个活动或片段。您希望绘制图像并按比例缩放。然后你应该在onCreate或onCreateView中写入如下代码:
LinearLayout rootLayout = (LinearLayout) findViewById(R.id.rootLayout);
ImageView image = (ImageView) findViewById(R.id.image);
// Wait till an activity is visible and image can be measured.
rootLayout.post(new Runnable() {
@Override
public void run() {
// Setting ImageView height with aspect ratio.
Drawable drawable = ContextCompat.getDrawable(getActivity(), R.drawable.your_image);
int height = getImageViewHeight(drawable, image);
// Rounding image corners.
float radius = getResources().getDimension(R.dimen.your_radius_in_dp);
Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
Bitmap result = getRoundedBitmap(bitmap, image.getWidth(), height, radius);
image.setImageBitmap(result);
}
});
其中设置新的图像高度为:
public static int getImageViewHeight(Drawable drawable, ImageView imageView) {
imageView.setImageDrawable(drawable);
int width = drawable.getIntrinsicWidth();
int height = 0;
if (width > 0) {
height = (drawable.getIntrinsicHeight() * imageView.getWidth()) / width;
imageView.getLayoutParams().height = height;
imageView.requestLayout();
}
return height;
}
然后,您应该编写一个方法来缩放图像并使其圆角。这里的width和height是位图的新维度(更小或更大)。在下面的例子中,我只圆角上的两个角。
private Bitmap getRoundedBitmap(Bitmap bitmap, int width, int height, float radius) {
// Create scaled bitmap.
Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmap, width, height, false);
BitmapShader shader = new BitmapShader(scaledBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setShader(shader);
Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(result);
// First make all corners round.
canvas.drawRoundRect(new RectF(0, 0, width, height), radius, radius, paint);
// Then draw bottom rectangle.
canvas.drawRect(0, height - radius, radius, height, paint);
canvas.drawRect(width - radius, height - radius, width, height, paint);
return result;
}
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