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
科特林
import android.graphics.BitmapFactory
import android.os.Bundle
import android.support.v4.graphics.drawable.RoundedBitmapDrawableFactory
import kotlinx.android.synthetic.main.activity_main.*
val bitmap = BitmapFactory.decodeResource(resources, R.drawable.myImage)
val rounded = RoundedBitmapDrawableFactory.create(resources, bitmap)
rounded.cornerRadius = 20f
profileImageView.setImageDrawable(rounded)
为了使ImageView成为圆形,我们可以改变拐角半径:
rounded.isCircular = true
其他回答
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);
}
}
试试这个
Bitmap finalBitmap;
if (bitmap.getWidth() != radius || bitmap.getHeight() != radius)
finalBitmap = Bitmap.createScaledBitmap(bitmap, radius, radius,
false);
else
finalBitmap = bitmap;
Bitmap output = Bitmap.createBitmap(finalBitmap.getWidth(),
finalBitmap.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, finalBitmap.getWidth(),
finalBitmap.getHeight());
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
paint.setDither(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(Color.parseColor("#BAB399"));
canvas.drawCircle(finalBitmap.getWidth() / 2 + 0.7f,
finalBitmap.getHeight() / 2 + 0.7f,
finalBitmap.getWidth() / 2 + 0.1f, paint);
paint.setXfermode(new PorterDuffXfermode(
android.graphics.PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(finalBitmap, rect, rect, paint);
return output;
我使用路径在图像画布上只画角。(我需要没有位图内存分配的解决方案)
@Override
protected void onDraw(final Canvas canvas) {
super.onDraw(canvas);
if (!hasRoundedCorners()) return;
mPaint.setStyle(Paint.Style.FILL);
mPaint.setStrokeWidth(0);
Path path = new Path();
path.setFillType(Path.FillType.INVERSE_WINDING);
path.addRoundRect(new RectF(0, 0, getWidth(), getHeight()), mRadius, mRadius, Path.Direction.CCW);
canvas.drawPath(path, mPaint);
}
注意,你不应该在onDraw方法中分配任何新对象。此代码是概念验证,不应该在产品代码中这样使用
看到更多: https://medium.com/@przemek.materna/rounded-image-view-no-bitmap-reallocation-11a8b163484d
我使用了一个自定义视图,我在其他视图的顶部布局,它只是画了4个小倒角,颜色与背景相同。
优点:
不分配位图。 适用于任何你想要应用圆角的视图。 适用于所有API级别;)
代码:
public class RoundedCornersView extends View {
private float mRadius;
private int mColor = Color.WHITE;
private Paint mPaint;
private Path mPath;
public RoundedCornersView(Context context) {
super(context);
init();
}
public RoundedCornersView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
TypedArray a = context.getTheme().obtainStyledAttributes(
attrs,
R.styleable.RoundedCornersView,
0, 0);
try {
setRadius(a.getDimension(R.styleable.RoundedCornersView_radius, 0));
setColor(a.getColor(R.styleable.RoundedCornersView_cornersColor, Color.WHITE));
} finally {
a.recycle();
}
}
private void init() {
setColor(mColor);
setRadius(mRadius);
}
private void setColor(int color) {
mColor = color;
mPaint = new Paint();
mPaint.setColor(mColor);
mPaint.setStyle(Paint.Style.FILL);
mPaint.setAntiAlias(true);
invalidate();
}
private void setRadius(float radius) {
mRadius = radius;
RectF r = new RectF(0, 0, 2 * mRadius, 2 * mRadius);
mPath = new Path();
mPath.moveTo(0,0);
mPath.lineTo(0, mRadius);
mPath.arcTo(r, 180, 90);
mPath.lineTo(0,0);
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
/*This just draws 4 little inverted corners */
int w = getWidth();
int h = getHeight();
canvas.drawPath(mPath, mPaint);
canvas.save();
canvas.translate(w, 0);
canvas.rotate(90);
canvas.drawPath(mPath, mPaint);
canvas.restore();
canvas.save();
canvas.translate(w, h);
canvas.rotate(180);
canvas.drawPath(mPath, mPaint);
canvas.restore();
canvas.translate(0, h);
canvas.rotate(270);
canvas.drawPath(mPath, mPaint);
}
}
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;
}