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
如果你们中有人面临这个问题
大多数情况下,你使用的是Android Studio。由于图像大小的调整和所有在Android工作室,你可能会遇到这个问题。解决这个问题的一个简单方法是减小drawCircle()中的圆的半径。在我的情况下,我使用这个修复
使用画布。drawCircle(100,100,90, paint);而不是帆布。drawCircle(100,100,100, paint);这绝对能解决你的问题。
下面是最终编辑的代码:-
public class Profile extends ActionBarActivity {
TextView username;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.profile);
username= (TextView) findViewById(R.id.txt);
String recievedusername=getIntent().getExtras().getString("toname");
username.setText(recievedusername);
Bitmap bm = BitmapFactory.decodeResource(getResources(),
R.mipmap.gomez);
Bitmap resizedBitmap = Bitmap.createScaledBitmap(bm, 200,200, false);
Bitmap conv_bm=getCircleBitmap(resizedBitmap,100);
// set circle bitmap
ImageView mImage = (ImageView) findViewById(R.id.profile_image);
mImage.setImageBitmap(conv_bm);
// TODO Auto-generated method stub
}
private Bitmap getCircleBitmap(Bitmap bitmap , int pixels) {
final Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Bitmap.Config.ARGB_8888);
final 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);
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawCircle(100,100, 90, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
bitmap.recycle();
return output;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_apploud, menu);
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_addnew) {
Intent i;
i=new Intent(Profile.this,ApplaudSomeone.class);
startActivity(i);
return true;
}
return super.onOptionsItemSelected(item);
}
}
其他回答
如果你不希望边框影响图像,使用这个类。不幸的是,我没有找到任何方法来绘制画布上的透明区域来到onDraw()。这里创建了一个新的位图它是画在一个真实的画布上的。
如果您想要创建一个消失的边界,该视图非常有用。如果你将borderWidth设置为0,边框将会消失,图像仍然保持圆角,就像边界一样。也就是说,它看起来就像边界完全由图像边缘绘制。
import android.annotation.SuppressLint
import android.content.Context
import android.graphics.Bitmap
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.graphics.PorterDuff
import android.graphics.PorterDuffXfermode
import android.graphics.RectF
import android.util.AttributeSet
import androidx.appcompat.widget.AppCompatImageView
class RoundedImageViewWithBorder @JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null,
defStyleAttr: Int = 0) : AppCompatImageView(context, attrs, defStyleAttr) {
var borderColor: Int = 0
set(value) {
invalidate()
field = value
}
var borderWidth: Int = 0
set(value) {
invalidate()
field = value
}
var cornerRadius: Float = 0f
set(value) {
invalidate()
field = value
}
private var bitmapForDraw: Bitmap? = null
private var canvasForDraw: Canvas? = null
private val transparentPaint = Paint().apply {
isAntiAlias = true
color = Color.TRANSPARENT
style = Paint.Style.STROKE
xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC)
}
private val borderPaint = Paint().apply {
isAntiAlias = true
style = Paint.Style.STROKE
}
private val transparentAreaRect = RectF()
private val borderRect = RectF()
init {
val typedArray = context.obtainStyledAttributes(attrs, R.styleable.RoundedImageViewWithBorder)
try {
borderWidth = typedArray.getDimensionPixelSize(R.styleable.RoundedImageViewWithBorder_border_width, 0)
borderColor = typedArray.getColor(R.styleable.RoundedImageViewWithBorder_border_color, 0)
cornerRadius = typedArray.getDimensionPixelSize(R.styleable.RoundedImageViewWithBorder_corner_radius, 0).toFloat()
} finally {
typedArray.recycle()
}
}
@SuppressLint("CanvasSize", "DrawAllocation")
override fun onDraw(canvas: Canvas) {
if (canvas.height <=0 || canvas.width <=0) {
return
}
if (canvasForDraw?.height != canvas.height || canvasForDraw?.width != canvas.width) {
val newBitmap = Bitmap.createBitmap(canvas.width, canvas.height, Bitmap.Config.ARGB_8888)
bitmapForDraw = newBitmap
canvasForDraw = Canvas(newBitmap)
}
bitmapForDraw?.eraseColor(Color.TRANSPARENT)
// Draw existing content
super.onDraw(canvasForDraw)
if (borderWidth > 0) {
canvasForDraw?.let { drawWithBorder(it) }
} else {
canvasForDraw?.let { drawWithoutBorder(it) }
}
// Draw everything on real canvas
bitmapForDraw?.let { canvas.drawBitmap(it, 0f, 0f, null) }
}
private fun drawWithBorder(canvas: Canvas) {
// Draw transparent area
transparentPaint.strokeWidth = borderWidth.toFloat() * 4
transparentAreaRect.apply {
left = -borderWidth.toFloat() * 1.5f
top = -borderWidth.toFloat() * 1.5f
right = canvas.width.toFloat() + borderWidth.toFloat() * 1.5f
bottom = canvas.height.toFloat() + borderWidth.toFloat() * 1.5f
}
canvasForDraw?.drawRoundRect(transparentAreaRect, borderWidth.toFloat() * 2 + cornerRadius, borderWidth.toFloat() * 2 + cornerRadius, transparentPaint)
// Draw border
borderPaint.color = borderColor
borderPaint.strokeWidth = borderWidth.toFloat()
borderRect.apply {
left = borderWidth.toFloat() / 2
top = borderWidth.toFloat() / 2
right = canvas.width.toFloat() - borderWidth.toFloat() / 2
bottom = canvas.height.toFloat() - borderWidth.toFloat() / 2
}
canvas.drawRoundRect(borderRect, cornerRadius - borderWidth.toFloat() / 2, cornerRadius - borderWidth.toFloat() / 2, borderPaint)
}
private fun drawWithoutBorder(canvas: Canvas) {
// Draw transparent area
transparentPaint.strokeWidth = cornerRadius * 4
transparentAreaRect.apply {
left = -cornerRadius * 2
top = -cornerRadius * 2
right = canvas.width.toFloat() + cornerRadius * 2
bottom = canvas.height.toFloat() + cornerRadius * 2
}
canvasForDraw?.drawRoundRect(transparentAreaRect, cornerRadius * 3, cornerRadius * 3, transparentPaint)
}
}
值:
<declare-styleable name="RoundedImageViewWithBorder">
<attr name="corner_radius" format="dimension|string" />
<attr name="border_width" format="dimension|reference" />
<attr name="border_color" format="color|reference" />
</declare-styleable>
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;
}
}
应用一个形状到你的imageView如下所示:
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid android:color="#faf5e6" />
<stroke
android:width="1dp"
android:color="#808080" />
<corners android:radius="15dp" />
<padding
android:bottom="5dp"
android:left="5dp"
android:right="5dp"
android:top="5dp" />
</shape>
这可能对你的朋友有帮助。
对于那些使用Glide和Kotlin的,你可以通过扩展RequestBuilder来实现
fun <T> GlideRequest<T>.roundCorners(cornerRadius: Int) =
apply(RequestOptions().transform(RoundedCorners(cornerRadius)))
并使用as;
GlideApp.with(context)
.load(url)
.roundCorners(context.resources.getDimension(R.dimen.radius_in_dp).toInt())
.into(imgView)
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>