异常信息记录：
Error:Failed to resolve: com.android.support:support-annotations:26.0.2
<a href="install.m2.repo">Install Repository and sync project</a><br><a href="openFile:D:/AndroidStudioProjects/Qsb2/appild.gradle">Open File</a><br><a href="open.dependency.in.project.structure">Show in Project Structure dialog</a> Error:Failed to resolve: com.android.support:support-annotations:26.0.2
<a href="install.m2.repo">Install Repository and sync project</a><br>
<a href="openFile:D:/AndroidStudioProjects/Qsb2/appild.gradle">Open File</a><br>
<a href="open.dependency.in.project.structure">Show in Project Structure dialog</a>
解决方法：
在项目的build.gradle里面最上层填写这样一句话：：：：
configurations.all {
resolutionStrategy.force 'com.android.support:support-annotations:23.1.0'
}