经过一些研究和数小时的测试后，我终于意识到 android 有一个叫做 DEX 64K 方法限制的东西.简而言之，在向项目中添加外部库时，您可以达到一个限制.当您达到该限制时，您可能需要使用 multidex.我个人决定减少导入的库数量，因为其中一些不是真正使用或不需要的.为了进一步了解 multidex，您应该阅读此内容，

After some research and hours of testing I finally realized that android has something called the DEX 64K Methods Limit. In simple words there's a limit you can reach when adding external libraries to your project. When you reaches that limit you might need to use multidex. Personally I decided to reduce the amount of libraries imported as some of them weren't really used or necesary. For further understanding of multidex you should read this,

http://developer.android.com/tools/building/multidex.html