我已经看过如何使用位图创建一个可绘制的圆形,以及如何在其周围添加轮廓(AKA描边),here。
我无法在不创建新位图的情况下找到如何执行类似的任务来仅舍入位图的一些角,而不是创建新的位图,并且仍然可以用于中心裁剪的ImageView。 / p>
这是我发现的,但它确实创建了一个新的位图,并且在带有中心裁剪的imageView(源here)中使用它时:
/**
* Create rounded corner bitmap from original bitmap.
*
* @param input Original bitmap.
* @param cornerRadius Corner radius in pixel.
* @param squareTL,squareTR,squareBL,squareBR where to use square corners instead of rounded ones.
*/
public static Bitmap getRoundedCornerBitmap(final Bitmap input, final float cornerRadius, final int w, final int h,
final boolean squareTL, final boolean squareTR, final boolean squareBL, final boolean squareBR) {
final Bitmap output = Bitmap.createBitmap(w, h, Config.ARGB_8888);
final Canvas canvas = new Canvas(output);
final int color = 0xff424242;
final Rect rect = new Rect(0, 0, w, h);
final RectF rectF = new RectF(rect);
// make sure that our rounded corner is scaled appropriately
Paint paint = new Paint();
paint.setXfermode(null);
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, cornerRadius, cornerRadius, paint);
// draw rectangles over the corners we want to be square
if (squareTL)
canvas.drawRect(0, 0, w / 2, h / 2, paint);
if (squareTR)
canvas.drawRect(w / 2, 0, w, h / 2, paint);
if (squareBL)
canvas.drawRect(0, h / 2, w / 2, h, paint);
if (squareBR)
canvas.drawRect(w / 2, h / 2, w, h, paint);
paint.setXfermode(PORTER_DUFF_XFERMODE_SRC_IN);
canvas.drawBitmap(input, 0, 0, paint);
return output;
}
而且,这是我发现创造一个可以在各个角落起作用的圆角可绘制的东西:
public static class RoundedCornersDrawable extends Drawable {
private final float mCornerRadius;
private final RectF mRect = new RectF();
private final BitmapShader mBitmapShader;
private final Paint mPaint;
public RoundedCornersDrawable(final Bitmap bitmap, final float cornerRadius) {
mCornerRadius = cornerRadius;
mBitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP,
Shader.TileMode.CLAMP);
mPaint = new Paint();
mPaint.setAntiAlias(false);
mPaint.setShader(mBitmapShader);
mRect.set(0, 0, bitmap.getWidth(), bitmap.getHeight());
}
@Override
protected void onBoundsChange(final Rect bounds) {
super.onBoundsChange(bounds);
mRect.set(0, 0, bounds.width(), bounds.height());
}
@Override
public void draw(final Canvas canvas) {
canvas.drawRoundRect(mRect, mCornerRadius, mCornerRadius, mPaint);
}
@Override
public int getOpacity() {
return PixelFormat.TRANSLUCENT;
}
@Override
public void setAlpha(final int alpha) {
mPaint.setAlpha(alpha);
}
@Override
public void setColorFilter(final ColorFilter cf) {
mPaint.setColorFilter(cf);
}
}
但是这个解决方案只有在imageView显示内容的同时才能保持与位图相同的宽高比,并且其大小也是预先确定的。
如何创建一个中心裁剪的drawable,它显示一个位图,具有特定角落的圆角,并且还能够在其周围显示轮廓/笔划?
我想在不创建新位图或扩展ImageView的情况下这样做。仅使用具有位图作为输入的drawable。
答案 0 :(得分:5)
SMART方式是使用PorterDuff混合模式。创造任何花哨的阴影,混合," crop"它非常简单和光滑。影响。你可以找到很多关于PorterDuff的好教程。这里是good one。
答案 1 :(得分:2)
我总是使用这个库来实现您的目标。你可以围绕你想要的任何角落,也可以添加笔划。
您可以使用它或查看它的源代码,只是为了获取灵感。
修改
无需使用图像视图并自行制作位图或绘图,并在图像视图中显示。 只需用圆形图像视图替换图像视图,它将为您处理一切,无需任何额外的代码工作! 这是样本:
<com.makeramen.roundedimageview.RoundedImageView
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/imageView1"
android:scaleType="centerCrop"
app:riv_corner_radius="8dp"
app:riv_border_width="2dp"
app:riv_border_color="#333333"
app:riv_oval="false" />
在代码中,只需将任何图像资源传递给它,或者使用任何Image Loader。
RoundedImageView myRoundedImage=(RoundedImageView)findViewById(R.id.imageView1);
myRoundedImage.setImageResource(R.drawable.MY_DRAWABLE);
// OR
ImageLoader.getInstance().displayImage(YOUR_IMAGE_URL, myRoundedImage);
如果你想让特定的角落四舍五入,试试这个:
<com.makeramen.roundedimageview.RoundedImageView
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/imageView1"
android:scaleType="centerCrop"
app:riv_corner_radius_top_right="8dp"
app:riv_corner_radius_bottom_right="8dp"
app:riv_border_width="2dp"
app:riv_border_color="#333333"
app:riv_oval="false" />
答案 2 :(得分:1)
好吧,您可以创建一个名为my_background的新.xml drawable并粘贴以下代码:
<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle"
>
<solid android:color="#00000000"/>
<corners
android:bottomLeftRadius="12dp"
android:bottomRightRadius="12dp"
android:topLeftRadius="12dp"
android:topRightRadius="12dp" />
<stroke
android:width="1dp"
android:color="#000000"
/>
</shape>
然后,将ImageButton的ImageView背景设置为新的drawable,如下所示:
android:background="@drawable/my_background"
android:scaleType="centerCrop"
或以编程方式:
myView.setBackground(R.drawable.my_background);
希望它有所帮助!
修改强>
要以编程方式创建类似的drawable,您可以使用它:
GradientDrawable shape = new GradientDrawable();
shape.setShape(GradientDrawable.RECTANGLE);
shape.setCornerRadii(new float[] { 8, 8, 8, 8, 0, 0, 0, 0 });
shape.setColor(Color.TRANSPARENT);
shape.setStroke(3, Color.BLACK);
v.setBackgroundDrawable(shape);
答案 3 :(得分:1)
好的,这是我的尝试。唯一的问题是“int corner”意味着是一组标志。例如0b1111
,其中每个1
表示要舍入的角,而0
则相反。订单是TOP_LEFT,TOP_RIGHT,BOTTOM_LEFT,BOTTOM_RIGHT。
首先使用示例用法,格式化为可读性:
((ImageView) findViewById(R.id.imageView)).setImageDrawable(
new RoundedRectDrawable(
getResources(),
bitmap,
(float) .15,
0b1101,
8,
Color.YELLOW
)
);
代码:
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.os.SystemClock;
/**
* Created by mliu on 4/15/16.
*/
public class RoundedRectDrawable extends BitmapDrawable {
private final BitmapShader bitmapShader;
private final Paint p;
private final RectF rect;
private final float borderRadius;
private final float outlineBorderRadius;
private final int w;
private final int h;
private final int corners;
private final int border;
private final int bordercolor;
public RoundedRectDrawable(final Resources resources, final Bitmap bitmap, float borderRadiusSeed, int corners, int borderPX, int borderColor) {
super(resources, bitmap);
bitmapShader = new BitmapShader(getBitmap(),
BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP);
final Bitmap b = getBitmap();
p = getPaint();
p.setAntiAlias(true);
p.setShader(bitmapShader);
w = b.getWidth();
h = b.getHeight();
rect = new RectF(0,0,w,h);
borderRadius = borderRadiusSeed * Math.min(w, h);
border = borderPX;
this.corners = corners;
this.bordercolor = borderColor;
outlineBorderRadius = borderRadiusSeed * Math.min(w+border,h+border);
}
@Override
public void draw(final Canvas canvas) {
if ((corners&0b1111)==0){
if (border>0) {
Paint border = new Paint();
border.setColor(bordercolor);
canvas.drawRect(rect, border);
}
canvas.drawRect(rect.left + border, rect.top + border, rect.width() - border, rect.height() - border, p);
} else {
if (border >0) {
Paint border = new Paint();
border.setColor(bordercolor);
canvas.drawRoundRect(rect, outlineBorderRadius, outlineBorderRadius, border);
if ((corners & 0b1000) == 0) {
//top left
canvas.drawRect(rect.left, rect.top, rect.width() / 2, rect.height() / 2, border);
}
if ((corners & 0b0100) == 0) {
//top right
canvas.drawRect(rect.width() / 2, rect.top, rect.width(), rect.height() / 2, border);
}
if ((corners & 0b0010) == 0) {
//bottom left
canvas.drawRect(rect.left, rect.height() / 2, rect.width() / 2, rect.height(), border);
}
if ((corners & 0b0001) == 0) {
//bottom right
canvas.drawRect(rect.width() / 2, rect.height() / 2, rect.width(), rect.height(), border);
}
}
canvas.drawRoundRect(new RectF(rect.left + border, rect.top + border, rect.width() - border, rect.height() - border), borderRadius, borderRadius, p);
if ((corners & 0b1000) == 0) {
//top left
canvas.drawRect(rect.left + border, rect.top + border, rect.width() / 2, rect.height() / 2, p);
}
if ((corners & 0b0100) == 0) {
//top right
canvas.drawRect(rect.width() / 2, rect.top + border, rect.width() - border, rect.height() / 2, p);
}
if ((corners & 0b0010) == 0) {
//bottom left
canvas.drawRect(rect.left + border, rect.height() / 2, rect.width() / 2, rect.height() - border, p);
}
if ((corners & 0b0001) == 0) {
//bottom right
canvas.drawRect(rect.width() / 2, rect.height() / 2, rect.width() - border, rect.height() - border, p);
}
}
}
}
因此,如果需要,首先处理轮廓,然后处理位图。它首先用圆角矩形标记画布,然后在每个角落“平方”,你不想圆。看起来非常低效,可能是,但在最小优化(corner = 0b0000,10 canvas.draw调用)之前的平均情况运行时间在S7上需要大约200us。而且,根据手机使用情况,这段时间是超级不一致的。我已经低至80us,高达1.5ms。
注意/警告:我对此很不好意思。这不是最佳选择。 SO上可能已有更好的答案。搜索主题有点不常见且难以搜索。我本来不打算发布这个,但是在撰写本文时,这仍然没有得到明确的答案,而且由于他们Drawable
的问题实际上使用非常类似的方法作为我可怕的解决方案,因此库OP不希望使用。所以,现在我不太尴尬地分享这个。另外,虽然我今天发布的内容是昨天写的95%,但我知道我从教程或SO帖子中获得了一些代码,但我不记得归因于谁因为我没有最终在我的项目中使用它。无论你是谁,都道歉。