Why does the "android: shadowColor" property not support the "selector"?

Question

Developer Tools: Eclipse IDE for Java Developers Juno Release + Android2.2 + ADT-21.0.1.zip

Usage: color / tab _color_text_shadow:

<?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_pressed="true" android:color="#ffffff"/> <item android:state_focused="true" android:color="#ffffff"/> <item android:state_checked="true" android:color="#ffffff"/> <item android:color="#f75893"/> </selector> 

values ​​/ styles.xml:

 <style name="main_tab_bottom"> <item name="android:shadowColor">@color/tab_color_text_shadow</item> <item name="android:shadowDy">2</item> <item name="android:shadowRadius">1</item> </style> <RadioButton xmlns:android="http://schemas.android.com/apk/res/android" style="@style/main_tab_bottom" android:layout_marginTop="2dip" android:drawableTop="@drawable/exam_menu" android:tag="radio_button1" android:text="检查" android:textStyle="bold" /> 

Question: Why does the "android: shadowColor" not support the "selector"?

adb bugreport:

 02-19 10:41:23.650: E/AndroidRuntime(29865): Caused by: java.lang.NumberFormatException: Invalid int: "res/color/tab_color_text_shadow.xml" 02-19 10:41:23.650: E/AndroidRuntime(29865): at java.lang.Integer.invalidInt(Integer.java) 02-19 10:41:23.650: E/AndroidRuntime(29865): at java.lang.Integer.parse(Integer.java) 02-19 10:41:23.650: E/AndroidRuntime(29865): at java.lang.Integer.parseInt(Integer.java) 02-19 10:41:23.650: E/AndroidRuntime(29865): at com.android.internal.util.XmlUtils.convertValueToInt(XmlUtils.java) 02-19 10:41:23.650: E/AndroidRuntime(29865): at android.content.res.TypedArray.getInt(TypedArray.java) 02-19 10:41:23.650: E/AndroidRuntime(29865): at android.widget.TextView.<init>(TextView.java) 02-19 10:41:23.650: E/AndroidRuntime(29865): at android.widget.Button.<init>(Button.java) 02-19 10:41:23.650: E/AndroidRuntime(29865): at android.widget.CompoundButton.<init>(CompoundButton.java) 02-19 10:41:23.650: E/AndroidRuntime(29865): at android.widget.RadioButton.<init>(RadioButton.java) 02-19 10:41:23.650: E/AndroidRuntime(29865): at android.widget.RadioButton.<init>(RadioButton.java) 

already publish in android project, issue 49793 .