this指向的是当前页面实例(针对this它在不同地方指向不同,此刻讨论作为页面实例的范畴), 但constructor中的this(语法层面的this)与componentDidMount中的this(React Native中this)是不一样的, 即构造函数中的this和构造函数完成后的this并不完全相同, 说明在React Native中,构造函数还要完成一些React Native的构建,直到...
这两种方法使用场景不同,应该在使用ES6 class时在构造函数中初始化状态,并在使用React.createClass时定义getInitialState方法。下面两种写法效果是一样的: class MyComponent extends React.Component { constructor(props) { super(props); this.state = { }; } } varMyComponent=React.createClass({ getInitialState...
本机系统: Mac react: "16.11.0" react-native: "0.62.2" node: 12.16.2 # node -v npm: 6.14.4 # npm -v 二、报错内容如下 2.1、报错问题 React native Redux - object is not a constructor (evaluating 'new ctor(props context)') 2.2、问题原因 组件如下使用 `Redux` 然后就报错啦!! import...
function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; } var App = /*#__PURE__*/function (_React$Component) { _inherits(...
Summary Currently, we first create ReanimatedModule and NodesManager in its constructor. Then, calling ReanimatedModule.installTurboModule invokes NodesManager.initWithContext which creates NativeP...
ES6 Class vs ES5 constructor function All In One ES6 类 vs ES5 构造函数 classES6{constructor() {// initthis.name=''; }getName() {returnthis.name; }setName(name ='') {if(name) {this.name= name ??''; } } }constes6 =newES6(); ...
this( applicationContext, reactInstanceDevHelper, packagerPathForJSBundleName, enableOnCreate, null, null, minNumShakes, null); } public DevSupportManagerBase( Context applicationContext, ReactInstanceDevHelper reactInstanceDevHelper, 0 comments on commit 39d9122 Please sign in to comment. Foo...
我在这里读了一些东西(,),我想知道是否确保初始化过程中提供的参数是正确的,这违反了构造函数不应该工作的准则。email or "." not in email:在我的例子中,我检查以确保名字和姓氏不是空白的,并且电子邮件是有效的。更新:我不是问它是否应该抛出,而是 ...
React Native async/await does not work correctly I want to choose photo before execute navigation.navigate(), but async/await doesn't work. I tried to change getphotoFromCamera function in Get_Image.js to async function and added await code to launc... ...
解决React Native:Error: Cannot find module 'asap/raw' /cjs/loader.js:507:25) at Module.require(internal/modules/cjs/loader.js:637:17) atrequire(internal/modules/cjs/helpers.js:20:18) 执行命令:npminstall 即可。 在使用react-native-tab-navigator组件的时候Cannot find module 'asap/raw' ...