我如何制作圆角布局?我想应用圆角到我的线性布局。
当前回答
使用CardView获得任何布局的圆角边缘。 使用card_view:cardCornerRadius="5dp"为cardview获得圆角布局边缘。
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
card_view:cardCornerRadius="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="15dp"
android:weightSum="1">
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".3"
android:text="@string/quote_code"
android:textColor="@color/white"
android:textSize="@dimen/text_head_size" />
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".7"
android:text="@string/quote_details"
android:textColor="@color/white"
android:textSize="@dimen/text_head_size" />
</LinearLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
其他回答
我认为更好的方法是合并两件事:
制作布局的位图,如下所示。 从位图绘制圆角图形,如下所示 在imageView上设置drawable。
这将处理其他解决方案无法解决的情况,例如内容有角落。
我认为它对gpu更友好,因为它显示了一个单层而不是两层。
唯一更好的方法是创建一个完全自定义的视图,但这需要大量代码,可能会花费大量时间。我认为我在这里提出的建议是两全其美的。
以下是如何做到这一点的一小段:
RoundedCornersDrawable.java
/**
* shows a bitmap as if it had rounded corners. based on :
* http://rahulswackyworld.blogspot.co.il/2013/04/android-drawables-with-rounded_7.html
* easy alternative from support library: RoundedBitmapDrawableFactory.create( ...) ;
*/
public class RoundedCornersDrawable extends BitmapDrawable {
private final BitmapShader bitmapShader;
private final Paint p;
private final RectF rect;
private final float borderRadius;
public RoundedCornersDrawable(final Resources resources, final Bitmap bitmap, final float borderRadius) {
super(resources, bitmap);
bitmapShader = new BitmapShader(getBitmap(), Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
final Bitmap b = getBitmap();
p = getPaint();
p.setAntiAlias(true);
p.setShader(bitmapShader);
final int w = b.getWidth(), h = b.getHeight();
rect = new RectF(0, 0, w, h);
this.borderRadius = borderRadius < 0 ? 0.15f * Math.min(w, h) : borderRadius;
}
@Override
public void draw(final Canvas canvas) {
canvas.drawRoundRect(rect, borderRadius, borderRadius, p);
}
}
CustomView.java
public class CustomView extends ImageView {
private View mMainContainer;
private boolean mIsDirty=false;
// TODO for each change of views/content, set mIsDirty to true and call invalidate
@Override
protected void onDraw(final Canvas canvas) {
if (mIsDirty) {
mIsDirty = false;
drawContent();
return;
}
super.onDraw(canvas);
}
/**
* draws the view's content to a bitmap. code based on :
* http://nadavfima.com/android-snippet-inflate-a-layout-draw-to-a-bitmap/
*/
public static Bitmap drawToBitmap(final View viewToDrawFrom, final int width, final int height) {
// Create a new bitmap and a new canvas using that bitmap
final Bitmap bmp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
final Canvas canvas = new Canvas(bmp);
viewToDrawFrom.setDrawingCacheEnabled(true);
// Supply measurements
viewToDrawFrom.measure(MeasureSpec.makeMeasureSpec(canvas.getWidth(), MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(canvas.getHeight(), MeasureSpec.EXACTLY));
// Apply the measures so the layout would resize before drawing.
viewToDrawFrom.layout(0, 0, viewToDrawFrom.getMeasuredWidth(), viewToDrawFrom.getMeasuredHeight());
// and now the bmp object will actually contain the requested layout
canvas.drawBitmap(viewToDrawFrom.getDrawingCache(), 0, 0, new Paint());
return bmp;
}
private void drawContent() {
if (getMeasuredWidth() <= 0 || getMeasuredHeight() <= 0)
return;
final Bitmap bitmap = drawToBitmap(mMainContainer, getMeasuredWidth(), getMeasuredHeight());
final RoundedCornersDrawable drawable = new RoundedCornersDrawable(getResources(), bitmap, 15);
setImageDrawable(drawable);
}
}
编辑:发现了一个不错的替代方案,基于“RoundKornersLayouts”库。有一个类将用于所有你想要扩展的布局类,四舍五入:
//based on https://github.com/JcMinarro/RoundKornerLayouts
class CanvasRounder(cornerRadius: Float, cornerStrokeColor: Int = 0, cornerStrokeWidth: Float = 0F) {
private val path = android.graphics.Path()
private lateinit var rectF: RectF
private var strokePaint: Paint?
var cornerRadius: Float = cornerRadius
set(value) {
field = value
resetPath()
}
init {
if (cornerStrokeWidth <= 0)
strokePaint = null
else {
strokePaint = Paint()
strokePaint!!.style = Paint.Style.STROKE
strokePaint!!.isAntiAlias = true
strokePaint!!.color = cornerStrokeColor
strokePaint!!.strokeWidth = cornerStrokeWidth
}
}
fun round(canvas: Canvas, drawFunction: (Canvas) -> Unit) {
val save = canvas.save()
canvas.clipPath(path)
drawFunction(canvas)
if (strokePaint != null)
canvas.drawRoundRect(rectF, cornerRadius, cornerRadius, strokePaint)
canvas.restoreToCount(save)
}
fun updateSize(currentWidth: Int, currentHeight: Int) {
rectF = android.graphics.RectF(0f, 0f, currentWidth.toFloat(), currentHeight.toFloat())
resetPath()
}
private fun resetPath() {
path.reset()
path.addRoundRect(rectF, cornerRadius, cornerRadius, Path.Direction.CW)
path.close()
}
}
然后,在每个自定义布局类中,添加类似于下面的代码:
class RoundedConstraintLayout : ConstraintLayout {
private lateinit var canvasRounder: CanvasRounder
constructor(context: Context) : super(context) {
init(context, null, 0)
}
constructor(context: Context, attrs: AttributeSet) : super(context, attrs) {
init(context, attrs, 0)
}
constructor(context: Context, attrs: AttributeSet, defStyle: Int) : super(context, attrs, defStyle) {
init(context, attrs, defStyle)
}
private fun init(context: Context, attrs: AttributeSet?, defStyle: Int) {
val array = context.obtainStyledAttributes(attrs, R.styleable.RoundedCornersView, 0, 0)
val cornerRadius = array.getDimension(R.styleable.RoundedCornersView_corner_radius, 0f)
val cornerStrokeColor = array.getColor(R.styleable.RoundedCornersView_corner_stroke_color, 0)
val cornerStrokeWidth = array.getDimension(R.styleable.RoundedCornersView_corner_stroke_width, 0f)
array.recycle()
canvasRounder = CanvasRounder(cornerRadius,cornerStrokeColor,cornerStrokeWidth)
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR2) {
setLayerType(FrameLayout.LAYER_TYPE_SOFTWARE, null)
}
}
override fun onSizeChanged(currentWidth: Int, currentHeight: Int, oldWidth: Int, oldheight: Int) {
super.onSizeChanged(currentWidth, currentHeight, oldWidth, oldheight)
canvasRounder.updateSize(currentWidth, currentHeight)
}
override fun draw(canvas: Canvas) = canvasRounder.round(canvas) { super.draw(canvas) }
override fun dispatchDraw(canvas: Canvas) = canvasRounder.round(canvas) { super.dispatchDraw(canvas) }
}
如果你希望支持属性,可以像在库中写的那样使用:
<resources>
<declare-styleable name="RoundedCornersView">
<attr name="corner_radius" format="dimension"/>
<attr name="corner_stroke_width" format="dimension"/>
<attr name="corner_stroke_color" format="color"/>
</declare-styleable>
</resources>
另一种选择,对于大多数用途来说可能更容易:使用MaterialCardView。它允许自定义圆角、笔画颜色和宽度以及仰角。
例子:
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:clipChildren="false" android:clipToPadding="false"
tools:context=".MainActivity">
<com.google.android.material.card.MaterialCardView
android:layout_width="100dp" android:layout_height="100dp" android:layout_gravity="center"
app:cardCornerRadius="8dp" app:cardElevation="8dp" app:strokeColor="#f00" app:strokeWidth="2dp">
<ImageView
android:layout_width="match_parent" android:layout_height="match_parent" android:background="#0f0"/>
</com.google.android.material.card.MaterialCardView>
</FrameLayout>
结果是:
请注意,如果您使用它,在笔画的边缘有一个轻微的工件问题(在那里留下一些内容像素)。放大就能看到。我在这里报道过这个问题。
编辑:似乎是固定的,但不是在IDE。报告在这里。
<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="#FFFFFF"/>
<stroke android:width="3dip" android:color="#B1BCBE" />
<corners android:radius="10dip"/>
<padding android:left="3dip" android:top="3dip" android:right="3dip" android:bottom="3dip" />
</shape>
@David,只是把padding的值和stroke一样,所以无论图像大小,边框都是可见的
1:在drawables中定义layout_bg.xml:
<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="#FFFFFF"/>
<stroke android:width="3dp" android:color="#B1BCBE" />
<corners android:radius="10dp"/>
<padding android:left="0dp" android:top="0dp" android:right="0dp" android:bottom="0dp" />
</shape>
2:添加layout_bg.xml作为布局的背景
android:background="@drawable/layout_bg"
对于API 21+,使用剪辑视图
在API 21中,圆形轮廓剪辑被添加到View类中。更多信息请参见培训文档或参考资料。
这个内置的功能使圆角非常容易实现。它适用于任何视图或布局,并支持适当的剪辑。
下面是该怎么做:
创建一个可绘制的圆形形状,并将其设置为视图的背景: android:背景= " @drawable / round_outline” 在代码中剪辑轮廓:setClipToOutline(true)
文档曾经说过,你可以设置android:clipToOutline=“true”的XML,但这个错误现在终于解决了,文档现在正确地指出,你只能在代码中这样做。
它的样子:
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,视图将背景的轮廓作为剪切和阴影目的的边界。
这意味着如果你想圆角的ImageView与setClipToOutline(),你的图像必须来自android:src而不是android:background(因为背景是用于圆角形状)。如果你必须使用背景来设置你的图像而不是src,你可以使用这个嵌套视图的解决方案:
创建一个外部布局,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)现在将被剪切到外部布局的圆形形状。
下面是一个XML文件的副本,用于创建一个具有白色背景,黑色边框和圆角的可绘制对象:
<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="#ffffffff"/>
<stroke android:width="3dp"
android:color="#ff000000"
/>
<padding android:left="1dp"
android:top="1dp"
android:right="1dp"
android:bottom="1dp"
/>
<corners android:bottomRightRadius="7dp" android:bottomLeftRadius="7dp"
android:topLeftRadius="7dp" android:topRightRadius="7dp"/>
</shape>
将其保存为可绘制目录下的XML文件, 使用它就像使用任何可绘制的背景(图标或资源文件),使用它的资源名(R.drawable.your_xml_name)
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