我看了一下API Intent的构造函数有一个是这样写的
public Intent (Context packageContext, Class<?> cls)
Since: API Level 1 Create an intent for a specific component. All other fields (action, data, type, class) are null, though they can be modified later with explicit calls. This provides a convenient way to create an intent that is intended to execute a hard-coded class name, rather than relying on the system to find an appropriate class for you; see setComponent(ComponentName) for more information on the repercussions of this.
Parameters
packageContext A Context of the application package implementing this class.
cls The component class that is to be used for the intent.
See Also
setClass(Context, Class)
setComponent(ComponentName)
Intent(String, android.net.Uri, Context, Class)
上面为什么他们的参数相对应?还有这句话The component class that is to be used for the intent.意思是说：用于目的的组件类，难道类也可以作为函数传递的参数，ActivityMain.this是 类名.this 这个用法我没见过啊
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难道类不可以参数传参？骚年你也该好好学学java了，，，
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如果没看错的话，楼主所列的Intent是用于Activity间跳转，这种格式下的Context packageContext是指当前Activity的名称，例如Activity01.this。后面的.class是指向要跳转的Activity，例如Activity02.class。再startActivity（intent）就能完成Activity01到Activity02的跳转。