颜色状态列表不是形状绘制对象认可 [英] Color State List not recognized in Shape Drawable

问题描述

我定义下绘制 my_background_drawable.xml ：

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item>
        <shape android:gravity="center"
            android:shape="rectangle">
            <solid android:color="@color/color_stateful" />
        </shape>
    </item>

    <item android:drawable="@drawable/selector_png_drawable" />
</layer-list>

和我还定义下列颜色状态列表资源 color_stateful.xml ：

And I also define following color state list resource color_stateful.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:state_pressed="true" android:color="#FF00ff00"/>
    <item android:color="#FFff0000"/>
</selector>

当我设置的给定 my_background_drawable 作为背景的​​一些看法，然后我无法观察到在 color_stateful.xml 我的形状，而视图状态实际上是改变（ selector_png_drawable.xml 是一个指标）。

When I set given my_background_drawable as a background for some view then I cannot observe any change in color defined in color_stateful.xml for my shape, while the view state is actually changed (selector_png_drawable.xml is an indicator).

然而，一切都只是罚款当我修改我的 my_background_drawable.xml 以下列方式：

However everything is just fine when I modify my my_background_drawable.xml in the following way:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
<!-- This doesn't work
    <item>
        <shape android:gravity="center"
            android:shape="rectangle">
            <solid android:color="@color/color_stateful" />
        </shape>
    </item>
-->
    <item>
        <selector xmlns:android="http://schemas.android.com/apk/res/android">
            <item android:state_pressed="true">
                <shape android:gravity="center"
                    android:shape="rectangle">
                    <solid android:color="#FF00ff00" />
                </shape>
            </item>

            <item>
                <shape android:gravity="center"
                    android:shape="rectangle">
                    <solid android:color="#FFff0000" />
                </shape>
            </item>
        </selector>
    </item>

    <item android:drawable="@drawable/selector_png_drawable"" />
</layer-list>

所以，这是真的，当 Col​​orStateList 资源内部使用的 ShapeDrawable 或者是颜色状态信息只是失去了我做错了？

So is it true that color state information is just lost when ColorStateList resource is used within a ShapeDrawable or am I doing it wrong?

推荐答案

A Col​​orStateList 不能对＆LT通过为属性;固体＆GT; 在一个XML定义或＆LT真的任何属性;形状＆GT; 。此属性夸大了XML作为一个颜色资源，然后传递到绘制对象的 setColor（）方法，该方法只需要一个ARGB值。

A ColorStateList cannot be passed as an attribute for <solid> in an XML definition, or really any attribute of a <shape>. This attribute is inflated out of the XML as a Color resource and then passed to the Drawable's setColor() method, which only takes a single ARGB value.

只有一种类型，它的目的是遏制和基于状态present多个项目绘制对象实例，那就是 StateListDrawable ，这是你会得到什么当你吹一个＆LT;选择＆GT; 。所有其他绘制对象实例是为了仅仅是这个系列的成员或绘制的独立。

There is only one type of Drawable instance that is designed to contain and present multiple items based on state, and that is StateListDrawable, which is what you get when you inflate a <selector>. All other Drawable instances are meant to simply be members of this collection or drawn standalone.

此外请注意膨胀＆LT;形状＆GT; 产品实际上是 GradientDrawable ，而不是 ShapeDrawable 。如果检查出膨胀（）的方法 GradientDrawable <一个href="http://$c$csearch.google.com/$c$csearch#uX1GffpyOZk/graphics/java/android/graphics/drawable/GradientDrawable.java">in来源，你可以得到所有你可以要求如何每个属性使用的细节。

Note also that an inflated <shape> item is actually a GradientDrawable and not a ShapeDrawable. If you check out the inflate() method of GradientDrawable in the source, you can get all the detail you could ask for on how each attribute is used.

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