问题描述
这个问题很简单.但我想知道我们究竟在哪里引用了 gui 元素?至于在哪里定义最好:
The question is quite simple. But I want to know where exactly do we make our references to the gui elements? As in which is the best place to define:
final EditText edit = (EditText) findViewById(R.id.text_xyz);
edit.getText.tostring();
当我在默认的 oncreate() 中尝试它时，我得到空值.因此，为了获得最佳实践，您是否推荐一个单独的类来引用 main.xml 中这些已定义的 gui 元素.从这里我们可以调用这些元素的各种方法，比如gettext或settext?
When I try it doing inside the default oncreate() I get null values. So for best practice, do u recommend a separate class for referring these already defined gui elements in main.xml. From here we can call various methods of these elements like gettext or settext?
推荐答案
好吧，这取决于您的需求.我经常在活动中保留对小部件的引用(作为类字段) - 并将它们设置在 onCreate 方法中.我认为这是个好主意
您的空值的原因可能是您尝试在 onCreate() 方法中设置 contentView() 之前调用 findViewById() -请检查一下.
Well, it depends on your needs. Very often I keep my references to widgets in activity (as a class fields) - and set them in onCreate method. I think that is a good idea
Probably the reason for your nulls is that you are trying to call findViewById() before you set contentView() in your onCreate() method - please check that.
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