isved（）与Android片段中的null！= getActivity（）相同吗？

Question

我想知道这两种方法是否会导致相同的结果，或者哪种方法比另一种更好。

if(isAdded()){
//do something with activity since fragment is currently added to its activity.
}

和

if(null != getActivity()){
//do something with activity. Its not null
}

Answer 1

出于以下两个原因，

isAdded()最好在几乎所有情况下使用：

如果片段当前已添加到其中，则

1. isAdded()将返回true 活动。 getActivity()只返回关联的活动。在大多数情况下，这将返回相同的布尔值，但最好是安全的

2. 编写

的代码较少

源代码：

http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/5.1.1_r1/android/app/Fragment.java/

/**
 * Return the Activity this fragment is currently associated with.
 */
final public Activity getActivity() {
    return mActivity;
}

/**
 * Return true if the fragment is currently added to its activity.
 */
final public boolean isAdded() {
    return mActivity != null && mAdded;
}