Error:(9) No resource identifier found for attribute 'XXXXX' in package 'XXXXX.

##Error:(9) No resource identifier found for attribute ‘XXXX’ in package ‘XXXXXX’

studio编译报错，具体报错原因如下:

Information:Gradle tasks [:app:assembleDebug]
Error:(23) No resource identifier found for attribute 'halfVisibleItemCount' in package 'com.example.cb.test'
Error:(9) No resource identifier found for attribute 'halfVisibleItemCount' in package 'com.example.cb.test'
Information:BUILD FAILED in 2s
Error:org.gradle.process.internal.ExecException: Process 'command 'F:\sdk\build-tools\26.0.2\aapt.exe'' finished with non-zero exit value 1
Error:(16) No resource identifier found for attribute 'halfVisibleItemCount' in package 'com.example.cb.test'
Error:java.util.concurrent.ExecutionException: com.android.ide.common.process.ProcessException: Error while executing process F:\sdk\build-tools\26.0.2\aapt.exe with arguments {package -f --no-crunch -I F:\sdk\platforms\android-26\android.jar -M \\?\F:\studioworkpalce\Test\app\build\intermediates\manifests\full\debug\AndroidManifest.xml -S F:\studioworkpalce\Test\app\build\intermediates\res\merged\debug -m -J \\?\F:\studioworkpalce\Test\app\build\generated\source\r\debug -F F:\studioworkpalce\Test\app\build\intermediates\res\debug\resources-debug.ap_ --custom-package com.example.cb.test -0 apk --preferred-density xhdpi --output-text-symbols \\?\F:\studioworkpalce\Test\app\build\intermediates\symbols\debug --no-version-vectors}
Error:(16) No resource identifier found for attribute 'halfVisibleItemCount' in package 'com.example.cb.test'
F:\studioworkpalce\Test\app\build\intermediates\res\merged\debug\layout\layout_date.xml
Error:(23) No resource identifier found for attribute 'halfVisibleItemCount' in package 'com.example.cb.test'
Error:Execution failed for task ':app:processDebugResources'.
> Failed to execute aapt
F:\studioworkpalce\Test\Library\build\intermediates\bundles\debug\res\layout\layout_date.xml
Error:(9) No resource identifier found for attribute 'halfVisibleItemCount' in package 'com.example.cb.test'
Error:com.android.ide.common.process.ProcessException: Error while executing process F:\sdk\build-tools\26.0.2\aapt.exe with arguments {package -f --no-crunch -I F:\sdk\platforms\android-26\android.jar -M \\?\F:\studioworkpalce\Test\app\build\intermediates\manifests\full\debug\AndroidManifest.xml -S F:\studioworkpalce\Test\app\build\intermediates\res\merged\debug -m -J \\?\F:\studioworkpalce\Test\app\build\generated\source\r\debug -F F:\studioworkpalce\Test\app\build\intermediates\res\debug\resources-debug.ap_ --custom-package com.example.cb.test -0 apk --preferred-density xhdpi --output-text-symbols \\?\F:\studioworkpalce\Test\app\build\intermediates\symbols\debug --no-version-vectors}

####根据提示，大概知道原因是应该自定义属性导致的，提示找不到自定义属性，下面就来讲我解决的过程。

1） 统一下build的版本，如compileSdkVersion,targetSdkVersion,v4,v7
2）查找自定义属性是否真的有报错信息里面的attribute “XXX”，没有的话从哪拷贝的就到原项目的attr.xml中拷贝过来。
3）确定下你的自定义属性是否指定了format类型，如果未指定就会报上面的错。（我报错的原因就是这个导致的）

如上自定义属性，如果不指定format=“XXX”就会报错（studio3.0）以下版本好像没事，我升级3。0后才出现这样的问题。
既然不能少format类型，那就给它加上就可以了，如下

还有一个attrs.xml中最好只有一个name，如果有两个自定义属性有相同的name也可能会报错。