问题：react native初次运行时，gradle加载很慢，导致最后总是启动项目不成功

解决方案：找到 .gradle 的目录，我这里本地是：C:\Users\Administrator\.gradle，一般在C盘的用户文件夹下，如果没有的话，运行react native项目后就有了，如果第一次运行就很顺利，那么恭喜你，如果不行的话，请往下看。

在C:\Users\Administrator\.gradle目录下新建一个gradle的初始化文件

 gradle的代码如下，保存后，再次启动react native就可以了。

注意：创建初始化文件后，. gradle文件夹下的其他缓存要删除后重新运行，只保留一个init.gradle配置文件就好

allprojects{
    repositories {
        def ALIYUN_REPOSITORY_URL = 'https://maven.aliyun.com/repository/central/'
        def ALIYUN_JCENTER_URL = 'https://maven.aliyun.com/repository/public/'
        all { ArtifactRepository repo ->
            if(repo instanceof MavenArtifactRepository){
                def url = repo.url.toString()
                if (url.startsWith('https://repo1.maven.org/maven2') || url.startsWith('http://repo1.maven.org/maven2')) {
                    project.logger.lifecycle "Repository ${repo.url} replaced by $ALIYUN_REPOSITORY_URL."
                    remove repo
                }
                if (url.startsWith('https://jcenter.bintray.com/') || url.startsWith('http://jcenter.bintray.com/')) {
                    project.logger.lifecycle "Repository ${repo.url} replaced by $ALIYUN_JCENTER_URL."
                    remove repo
                }
            }
        }
        maven {
            url ALIYUN_REPOSITORY_URL
            url ALIYUN_JCENTER_URL
			url 'https://maven.aliyun.com/repository/google/'
			url 'https://maven.aliyun.com/repository/gradle-plugin/'
        }
    }
 
 
    buildscript{
        repositories {
            def ALIYUN_REPOSITORY_URL = 'https://maven.aliyun.com/repository/central/'
            def ALIYUN_JCENTER_URL = 'https://maven.aliyun.com/repository/public/'
            all { ArtifactRepository repo ->
                if(repo instanceof MavenArtifactRepository){
                    def url = repo.url.toString()
                    if (url.startsWith('https://repo1.maven.org/maven2') || url.startsWith('http://repo1.maven.org/maven2')) {
                        project.logger.lifecycle "Repository ${repo.url} replaced by $ALIYUN_REPOSITORY_URL."
                        remove repo
                    }
                    if (url.startsWith('https://jcenter.bintray.com/') || url.startsWith('http://jcenter.bintray.com/')) {
                        project.logger.lifecycle "Repository ${repo.url} replaced by $ALIYUN_JCENTER_URL."
                        remove repo
                    }
                }
            }
            maven {
                url ALIYUN_REPOSITORY_URL
                url ALIYUN_JCENTER_URL
				url 'https://maven.aliyun.com/repository/google/'
				url 'https://maven.aliyun.com/repository/gradle-plugin/'
            }
        }
    }
}