1. **一下提供偽代碼，僅說明自己的理解，思路**/ 
2. /*************************************************/ 
3. /*假設*/ 
4. AActivity,BActivity,CActivity,DActivity 都extends ActivityGroup. 
5. A1Activity,B1Activity,C1Activity,D1Activity 都extends Activity. 
6. A2Activity,B2Activity,C2Activity,D2Activity 都extends Activity 
7.  
8. /*一，AActivity繼承了Activity，調用startActivity()的時候會在tab內部contentView顯示A1Activity*/ 
9. AActivity.this.startActivity(A1Activity.class) 
10. BActivity.this.startActivity(B1Activity.class) 
11. CActivity.this.startActivity(C1Activity.class) 
12. DActivity.this.startActivity(D1Activity.class) 
13.  
14. /*二，A1Activity沒有繼承ActivityGroup，所以調用startActivity()的時候和普通的調用沒有區別，A2會填滿窗口*/ 
15. A1Activity.this.startActivity(A2Activity.class) 
16. B1Activity.this.startActivity(B2Activity.class) 
17. C1Activity.this.startActivity(C2Activity.class) 
18. D1Activity.this.startActivity(D2Activity.class) 
19.  
20. /*三，A1Activity.this.getParent()獲得的是AActivity, 其實就是ActivityGroup； 雖然A1Activity沒有繼承ActivityGroup，但是A2Activity實際是由A1Activity的父類AActivity啟動的,所以A2Activity的啟動效果和一差不多*/ 
21. A1Activity.this.getParent().startActivity(A2Activity.class) 
22. B1Activity.this.getParent().startActivity(B2Activity.class) 
23. C1Activity.this.getParent().startActivity(C2Activity.class) 
24. D1Activity.this.getParent().startActivity(D2Activity.class)