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
一个快速的xml解决方案-
<android.support.v7.widget.CardView
android:layout_width="40dp"
android:layout_height="40dp"
app:cardElevation="0dp"
app:cardCornerRadius="4dp">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/rounded_user_image"
android:scaleType="fitXY"/>
</android.support.v7.widget.CardView>
你可以在CardView上设置你想要的宽度,高度和半径,在ImageView上设置scaleType。
对于AndroidX,使用< AndroidX .cardview.widget. cardview >
其他回答
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);
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>
非常感谢第一个回答。下面是修改后的版本,将矩形图像转换为正方形(和圆形),填充颜色作为参数传递。
public static Bitmap getRoundedBitmap(Bitmap bitmap, int pixels, int color) {
Bitmap inpBitmap = bitmap;
int width = 0;
int height = 0;
width = inpBitmap.getWidth();
height = inpBitmap.getHeight();
if (width <= height) {
height = width;
} else {
width = height;
}
Bitmap output = Bitmap.createBitmap(width, height, Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, width, height);
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(Mode.SRC_IN));
canvas.drawBitmap(inpBitmap, rect, rect, paint);
return output;
}
在API 21的View类中添加了对圆形形状的剪切。
只要这样做:
创建一个可绘制的圆形形状,就像这样:
res - drawable round_outline xml。
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<corners android:radius="10dp" />
...
</shape>
设置drawable作为ImageView的背景: android:背景= " @drawable / round_outline” 根据这个文档,那么你所需要做的就是添加android:clipToOutline="true"
不幸的是,有一个错误,无法识别该XML属性。幸运的是,我们仍然可以在Java中设置剪辑:
在你的活动或片段中:
下面是它的样子:
注意:
此方法适用于任何可绘制的形状(不仅仅是圆角)。它会剪辑ImageView到你在Drawable xml中定义的任何形状轮廓。
关于ImageViews的特别说明
setClipToOutline()仅在视图的背景设置为可绘制的形状时才有效。如果此背景形状存在,视图将形状的轮廓作为剪切和阴影目的的边界。
这意味着,如果你想使用setClipToOutline()圆角的ImageView,你的图像必须设置使用android:src而不是android:background(因为背景必须设置为您的圆角形状)。如果你必须使用背景来设置你的图像而不是src,你可以使用这个解决方案:
创建一个布局,并将其背景设置为可绘制的形状 将布局包装在ImageView周围(没有填充) ImageView(包括布局中的任何其他内容)现在将以圆角布局形状显示。
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;
}
}