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
为什么不在draw()中进行剪辑?
以下是我的解决方案:
用剪切扩展RelativeLayout 将ImageView(或其他视图)放入布局中:
代码:
public class RoundRelativeLayout extends RelativeLayout {
private final float radius;
public RoundRelativeLayout(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray attrArray = context.obtainStyledAttributes(attrs,
R.styleable.RoundRelativeLayout);
radius = attrArray.getDimension(
R.styleable.RoundRelativeLayout_radius, 0);
}
private boolean isPathValid;
private final Path path = new Path();
private Path getRoundRectPath() {
if (isPathValid) {
return path;
}
path.reset();
int width = getWidth();
int height = getHeight();
RectF bounds = new RectF(0, 0, width, height);
path.addRoundRect(bounds, radius, radius, Direction.CCW);
isPathValid = true;
return path;
}
@Override
protected void dispatchDraw(Canvas canvas) {
canvas.clipPath(getRoundRectPath());
super.dispatchDraw(canvas);
}
@Override
public void draw(Canvas canvas) {
canvas.clipPath(getRoundRectPath());
super.draw(canvas);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int oldWidth = getMeasuredWidth();
int oldHeight = getMeasuredHeight();
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int newWidth = getMeasuredWidth();
int newHeight = getMeasuredHeight();
if (newWidth != oldWidth || newHeight != oldHeight) {
isPathValid = false;
}
}
}
其他回答
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:
对于圆形边界使用下面的代码
<com.google.android.material.card.MaterialCardView
android:id="@+id/circle"
android:layout_width="45dp"
android:layout_height="45dp"
android:layout_marginStart="5dp"
app:cardCornerRadius="25dp"
app:strokeColor="@color/colorDarkGreen"
app:strokeWidth="1dp">
<ImageView
android:id="@+id/toolbarProfile"
android:scaleType="fitXY"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="@drawable/avater" />
</com.google.android.material.card.MaterialCardView>
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。
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);
}
}
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);