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未定义不是对象(uiconstants)

react-native reactjs javascript

Roger Coll · 技术社区 · 6 年前

在React Native中,我有这个类(来自Kittentricks):

  import {Platform} from 'react-native';

export class UIConstants {
  static AppbarHeight = Platform.OS === 'ios' ? 44 : 56;
  static StatusbarHeight = Platform.OS === 'ios' ? 20 : 0;
  static HeaderHeight = UIConstants.AppbarHeight + UIConstants.StatusbarHeight;
}

类的名称:appconstants.js

问题是当我尝试导出这个类时。我得到这个错误:

undefined is not an object(evaluating 'UIConstants.AppbarHeight')

2 回复 | 直到 6 年前

hsz 6 年前

const appbarHeight = Platform.OS === 'ios' ? 44 : 56;
const statusbarHeight = Platform.OS === 'ios' ? 20 : 0;

export class UIConstants {
  static AppbarHeight = appbarHeight;
  static StatusbarHeight = statusbarHeight;
  static HeaderHeight = appbarHeight + statusbarHeight;
}