android.content.Context 与 android.app.Activity

Question

我想将当前 Activity 的引用传递给不扩展 Activity 的类的方法。我需要使用对 Activity Activity 的引用，以便我可以使用 getWindow().addFlags(LayoutParams.FLAG_KEEP_SCREEN_ON);

我在类中使用这些 setter 方法将当前上下文和 Activity 传递给类对象:

public class VersionCheck {

    public Context context;
    public Activity activity;

    //---------------------------------------------------------------------------------------------------------
    //set the current context
    //---------------------------------------------------------------------------------------------------------
    public void setContext(Context context) {

        this.context = context;
    }

    //---------------------------------------------------------------------------------------------------------
    //set the current activity
    //---------------------------------------------------------------------------------------------------------
    public void setActivity(Activity activity) {

        this.activity = activity;
    }   

对 Activity 的引用在类中的 AsyncTask 中使用(摘录如下):

//---------------------------------------------------------------------------------------------------------
//asynchronous task to check if there is a newer version of the app available
//---------------------------------------------------------------------------------------------------------
private class UpdateCheckTask extends AsyncTask<String, Void, String> {

HttpClient httpclient;
HttpPost httppost;
HttpResponse response;
InputStream inputStream;
byte[] data;
StringBuffer buffer;

protected void onPreExecute ()
{
    VersionCheck vc = new VersionCheck();

    //do not lock screen or drop connection to server on login
        activity.getWindow().addFlags(LayoutParams.FLAG_KEEP_SCREEN_ON);

        //initiate progress dialogue to block user input during initial data retrieval
        ProcessingDialog = ProgressDialog.show(context, "Please Wait", "Checking for Updates", true,false);
}

    @Override
    protected String doInBackground(String... currentVersion) 
    {

如何获取对 Activity 的引用，以便将其传递给 setActivity(Activity) 方法？我使用 myActivity.this 作为上下文的引用。 Activity 也一样吗？

Answer 1

是的，Activity 也是一样的.................

http://developer.android.com/reference/android/app/Activity.html

看这里Context是Activity的父类(super class)......

java.lang.Object

   ↳    android.content.Context

       ↳    android.content.ContextWrapper

           ↳    android.view.ContextThemeWrapper

               ↳    android.app.Activity