android - 如何理解类型 "Context"？

Question

private static class OpenHelper extends SQLiteOpenHelper {
    OpenHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}}

我无法理解 Context 类型的含义。看了说明书还是看不懂。

Answer 1

上下文是一个接口(interface)!

根据源码:

Interface to global information about an application environment. This is an abstract class >whose implementation is provided by the Android system. It allows access to application-specific resources and classes, as well as up-calls for application-level operations such as launching activities, broadcasting and receiving intents, etc.

参见 http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.0.4_r1.2/android/content/Context.java#Context为了最好的理解