Android存储媒体文件：使用raw /文件夹还是资产/文件夹？

Question

Why choose one over the other? How are they stored on the phone?

Thanks

Answer 1

With resources, there's built-in support for providing alternatives for different languages, OS versions, screen orientations, etc., as described here . None of that is available with assets. Also, many parts of the API support the use of resource identifiers. Finally, the names of the resources are turned into constant field names that are checked at compile time, so there's less of an opportunity for mismatches between the code and the resources themselves. None of that applies to assets.

So why have an assets folder at all? If you want to compute the asset you want to use at run time, it's pretty easy. With resources, you would have to declare a list of all the resource IDs that might be used and compute an index into the the list. (This is kind of awkward and introduces opportunities for error if the set of resources changes in the development cycle.) You can retrieve a resource ID by name using getIdentifier , but this loses the benefits of compile-time checking. Assets can also be organized into a folder hierarchy, which is not supported by resources. It's a different way of managing data. Although resources cover most of the cases, assets have their occasional use.

One other difference: resources defined in a library project are automatically imported to application projects that depend on the library. For assets, that doesn't happen; asset files must be present in the assets directory of the application project(s).