【起航计划 010】2015 起航计划 Android APIDemo的魔鬼步伐 09 App->Activity->Redirection 根据shared preferences是否有值决定是否redirect

            //
             Retrieve the current text preference.  If there is no text
        
            //
             preference set, we need to get it from the user by invoking the
        
            //
             activity that retrieves it.  To do this cleanly, we will
        
            //
             temporarily hide our own activity so it is not displayed until the
        
            //
             result is returned.
            if (!loadPrefs()) {
            Intent intent = new Intent(this, RedirectGetter.class);
            startActivityForResult(intent, INIT_TEXT_REQUEST);
        }

            private
            final
            boolean
             loadPrefs() {
        
            //
             Retrieve the current redirect values.
        
            //
             NOTE: because this preference is shared between multiple
        
            //
             activities, you must be careful about when you read or write
        
            //
             it in order to keep from stepping on yourself.
        SharedPreferences preferences = getSharedPreferences("RedirectData", 0);

        mTextPref = preferences.getString("text", null);
        if (mTextPref != null) {
            TextView text = (TextView)findViewById(R.id.text);
            text.setText(mTextPref);
            returntrue;
        }

        returnfalse;
    }