如果您将 compileSdkVersion 更改为 21，您的应用程序将干净利落地编译.话虽如此，Google 退出内置 HttpClient 实现是有原因的，因此您可能应该寻求其他一些库.那其他图书馆"可能是:

If you change your compileSdkVersion to 21, your app will compile cleanly. That being said, there are reasons why Google is backing away from the built-in HttpClient implementation, so you probably should pursue some other library. That "some other library" could be:

• 内置的经典 Java HttpUrlConnection，尽管如您所见，它的 API 仍有不足之处
• Apache 独立打包 HttpClient for Android
• OkHttp(我的推荐)
• AndroidAsync

• the built-in classic Java HttpUrlConnection, though as you have found, its API leaves something to be desired
• Apache's independent packaging of HttpClient for Android
• OkHttp (my recommendation)
• AndroidAsync

特别是 OkHttp 似乎有一个非常好的 API 用于发布文件和 发布多部分表单，这应该类似于您的 HttpClient 代码

In particular, OkHttp seems to have a pretty good API for posting a file and posting a multipart form, which should be similar to what your HttpClient code is doing.