在DialogFragment中，onCreate应该做什么? [英] In a DialogFragment, what should onCreate do?

问题描述

我目前正在使用DialogFragment来学习使用它.我认为与onCreateView()相比，onCreate()可以做到:

I am currently messing around with DialogFragment to learn to use it. I assumed that compared to onCreateView(), onCreate() can do this:

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    testTextView.setText("SUCCESS!"); //ERROR HERE
}

但是我错了.不知道为什么它不起作用.当我注释掉testTextView.setText("Success!");时，错误消失了 该错误是NullPointerException，然后它仅标记了行39，这是有问题的代码所在的位置.任何澄清都值得赞赏.

But I am wrong. Not sure why its not working. The error goes away when I comment out testTextView.setText("Success!"); The error is a NullPointerException, and then it just flags line 39 which is where the offending line of code is. Any clarifications much appreciated.

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
    View testView = (View)inflater.inflate(R.layout.test_dialog_file, container, false);
    //instantiated testTextView globally
    testTextView = (TextView)testView.findViewById(R.id.set_text);
    testTextView.setText("SUCCESS!");
    return testView;
}

推荐答案

testTextView没有指向任何对象，因此请尝试类似

testTextView is NOT pointing to any object so try something like

testTextView = (TextView) findViewById(R.id.testTextView);

如果您看到片段的生命周期，说onCreateView在之后 onCreate被称为，因此您的onCreate没有对对象的任何引用，即布局中的textview

If you see the lifecycle of a fragment, it says that onCreateView is called after onCreate hence your onCreate doesn't have any reference to your object, that is textview in your layout

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