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
从材质组件库的1.2.0-alpha03版本开始,有了新的ShapeableImageView。
你可以这样使用:
<com.google.android.material.imageview.ShapeableImageView
...
app:shapeAppearanceOverlay="@style/roundedImageView"
app:srcCompat="@drawable/ic_image" />
在你的主题。xml:
<style name="roundedImageView" parent="">
<item name="cornerFamily">rounded</item>
<item name="cornerSize">8dp</item>
</style>
或通过编程:
float radius = getResources().getDimension(R.dimen.default_corner_radius);
imageView.setShapeAppearanceModel(imageView.getShapeAppearanceModel()
.toBuilder()
.setAllCorners(CornerFamily.ROUNDED,radius)
.build());
使用jetpack compose,您可以使用RoundedCornerShape应用剪辑修饰器:
Image(
painter = painterResource(R.drawable.xxxx),
contentDescription = "xxxx",
contentScale = ContentScale.Crop,
modifier = Modifier
.size(64.dp)
.clip(RoundedCornerShape(8.dp))
)
其他回答
为了Glide 4.x.x
使用下面的简单代码
Glide
.with(context)
.load(uri)
.apply(
RequestOptions()
.circleCrop())
.into(imageView)
/**
* 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);
}
}
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;
}
有一个很酷的库可以让你塑造imageviews。
这里有一个例子:
<com.github.siyamed.shapeimageview.mask.PorterShapeImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:siShape="@drawable/shape_rounded_rectangle"
android:src="@drawable/neo"
app:siSquare="true"/>
形状定义:
<shape android:shape="rectangle" xmlns:android="http://schemas.android.com/apk/res/android">
<corners
android:topLeftRadius="18dp"
android:topRightRadius="18dp"
android:bottomLeftRadius="18dp"
android:bottomRightRadius="18dp" />
<solid android:color="@color/black" />
</shape>
结果:
下面的代码创建一个圆角矩形布局对象,该对象围绕放置在其中的任何子对象绘制圆角矩形。它还演示了如何在不使用布局xml文件的情况下以编程方式创建视图和布局。
package android.example;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
import android.widget.TextView;
public class MessageScreen extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
int mainBackgroundColor = Color.parseColor("#2E8B57");
int labelTextColor = Color.parseColor("#FF4500");
int messageBackgroundColor = Color.parseColor("#3300FF");
int messageTextColor = Color.parseColor("#FFFF00");
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
float density = metrics.density;
int minMarginSize = Math.round(density * 8);
int paddingSize = minMarginSize * 2;
int maxMarginSize = minMarginSize * 4;
TextView label = new TextView(this);
/*
* The LayoutParams are instructions to the Layout that will contain the
* View for laying out the View, so you need to use the LayoutParams of
* the Layout that will contain the View.
*/
LinearLayout.LayoutParams labelLayoutParams = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
label.setLayoutParams(labelLayoutParams);
label.setTextSize(TypedValue.COMPLEX_UNIT_SP, 18);
label.setPadding(paddingSize, paddingSize, paddingSize, paddingSize);
label.setText(R.string.title);
label.setTextColor(labelTextColor);
TextView message = new TextView(this);
RoundedRectangle.LayoutParams messageLayoutParams = new RoundedRectangle.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
/*
* This is one of the calls must made to force a ViewGroup to call its
* draw method instead of just calling the draw method of its children.
* This tells the RoundedRectangle to put some extra space around the
* View.
*/
messageLayoutParams.setMargins(minMarginSize, paddingSize,
minMarginSize, maxMarginSize);
message.setLayoutParams(messageLayoutParams);
message.setTextSize(TypedValue.COMPLEX_UNIT_SP, paddingSize);
message.setText(R.string.message);
message.setTextColor(messageTextColor);
message.setBackgroundColor(messageBackgroundColor);
RoundedRectangle messageContainer = new RoundedRectangle(this);
LinearLayout.LayoutParams messageContainerLayoutParams = new LinearLayout.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
messageContainerLayoutParams.setMargins(paddingSize, 0, paddingSize, 0);
messageContainer.setLayoutParams(messageContainerLayoutParams);
messageContainer.setOrientation(LinearLayout.VERTICAL);
/*
* This is one of the calls must made to force a ViewGroup to call its
* draw method instead of just calling the draw method of its children.
* This tells the RoundedRectangle to color the the exta space that was
* put around the View as well as the View. This is exterior color of
* the RoundedRectangle.
*/
messageContainer.setBackgroundColor(mainBackgroundColor);
/*
* This is one of the calls must made to force a ViewGroup to call its
* draw method instead of just calling the draw method of its children.
* This is the interior color of the RoundedRectangle. It must be
* different than the exterior color of the RoundedRectangle or the
* RoundedRectangle will not call its draw method.
*/
messageContainer.setInteriorColor(messageBackgroundColor);
// Add the message to the RoundedRectangle.
messageContainer.addView(message);
//
LinearLayout main = new LinearLayout(this);
LinearLayout.LayoutParams mainLayoutParams = new LinearLayout.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
main.setLayoutParams(mainLayoutParams);
main.setOrientation(LinearLayout.VERTICAL);
main.setBackgroundColor(mainBackgroundColor);
main.addView(label);
main.addView(messageContainer);
setContentView(main);
}
}
RoundedRectangle布局对象的类定义如下:
/**
* A LinearLayout that draws a rounded rectangle around the child View that was added to it.
*/
package android.example;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.widget.LinearLayout;
/**
* A LinearLayout that has rounded corners instead of square corners.
*
* @author Danny Remington
*
* @see LinearLayout
*
*/
public class RoundedRectangle extends LinearLayout {
private int mInteriorColor;
public RoundedRectangle(Context p_context) {
super(p_context);
}
public RoundedRectangle(Context p_context, AttributeSet attributeSet) {
super(p_context, attributeSet);
}
// Listener for the onDraw event that occurs when the Layout is drawn.
protected void onDraw(Canvas canvas) {
Rect rect = new Rect(0, 0, getWidth(), getHeight());
RectF rectF = new RectF(rect);
DisplayMetrics metrics = new DisplayMetrics();
Activity activity = (Activity) getContext();
activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
float density = metrics.density;
int arcSize = Math.round(density * 10);
Paint paint = new Paint();
paint.setColor(mInteriorColor);
canvas.drawRoundRect(rectF, arcSize, arcSize, paint);
}
/**
* Set the background color to use inside the RoundedRectangle.
*
* @param Primitive int - The color inside the rounded rectangle.
*/
public void setInteriorColor(int interiorColor) {
mInteriorColor = interiorColor;
}
/**
* Get the background color used inside the RoundedRectangle.
*
* @return Primitive int - The color inside the rounded rectangle.
*/
public int getInteriorColor() {
return mInteriorColor;
}
}