React-navigation导航系统(5)-Router

本文主要是介绍React-navigation导航系统(5)-Router，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

tags: React-Native

Routers

Router定义一个组件的navigation state,允许开发者定义路径和可以操作的actions.

内建的Routers

StackRouter
TabRouter

使用Routers

为了手动定制一个navigator,在组件里可以放一个静态的router.(使用内建的组件快速的定制一个navigator,使用Navigator Factory更容易实现).

 class MyNavigator extends React.Component {static router = StackRouter(routes, config);...
}

现在你可以把这个组件作为另一个navigator的screen对待,MyNavigator的导航逻辑在StackRouter中定义.

定制化Router

看看[定制Router API 部分](https://reactnavigation.org/docs/routers/api)学习StackRouter和TabRouter的API.
只要你愿意也可以重写router的函数.

定制Navigation的Actions

为了重写navigation的行为,你可以在getStateForAction中重写navigation state的逻辑,从而手动处理routes和index.

 const MyApp = StackNavigator({Home: { screen: HomeScreen },Profile: { screen: ProfileScreen },
}, {initialRouteName: 'Home',
})
MyApp.router = {...MyApp.router,getStateForAction(action, state) {if (state && action.type === 'PushTwoProfiles') {const routes = [...state.routes,{key: 'A', routeName: 'Profile', params: { name: action.name1 }},{key: 'B', routeName: 'Profile', params: { name: action.name2 }},];return {...state,routes,index: routes.length - 1,};}return MyApp.router.getStateForAction(action, state);},
};

阻止某些Navigation的Actions

有时候根据你的route,需要阻止某些navigation的活动

 const MyStackRouter = StackRouter({Home: { screen: HomeScreen },Profile: { screen: ProfileScreen },
}, {initialRouteName: 'Home',
})
const MyAppRouter = {...MyStackRouter,getStateForAction(action, state) {if (state &&action.type === NavigationActions.BACK &&state.routes[state.index].params.isEditing) {// Returning null from getStateForAction means that the action// has been handled/blocked, but there is not a new statereturn null;}return MyStackRouter.getStateForAction(action, state);},
};

操作定制URIs

或许你的app有一个独特的URI,内建的routers处理不了.你可以通过getActionForPathAndParams来扩展router.

 import { NavigationActions } from 'react-navigation'const MyApp = StackNavigator({Home: { screen: HomeScreen },Profile: { screen: ProfileScreen },
}, {initialRouteName: 'Home',
})
const previousGetActionForPathAndParams = MyApp.router.getActionForPathAndParams
Object.assign(MyApp.router, {getActionForPathAndParams(path, params) {if (path === 'my/custom/path' &&params.magic === 'yes') {// returns a profile navigate action for /my/custom/path?magic=yesreturn NavigationActions.navigate({routeName: 'Profile',action: NavigationActions.navigate({// This child action will get passed to the child router// ProfileScreen.router.getStateForAction to get the child// navigation state.routeName: 'Friends',}),});}return previousGetActionForPathAndParams(path, params);},
};

定制Router API

你可以童工下面的函数来构建自己的router对象,

 const MyRouter = {getStateForAction: (action, state) => ({}),getActionForPathAndParams: (path, params) => null,getPathAndParamsForState: (state) => null,getComponentForState: (state) => MyScreen,getComponentForRouteName: (routeName) => MyScreen,
};// Now, you can make a navigator by putting the router on it:
class MyNavigator extends React.Component {static router = MyRouter;render() {...}
}

getStateForAction(action,state)

根据给定的action来定义返回的navigation sate.当一个action通过props.navigation.dispatch()传递,或者任何其他的助手函数被调用,例如navigation.navitate()的时候,这个函数将会运行.

通常这个函数将会以下面的形式返回navitaion state.

 {index: 1, // identifies which route in the routes array is activeroutes: [{// Each route needs a name to identify the type.routeName: 'MyRouteName',// A unique identifier for this route in the routes array:key: 'myroute-123',// (used to specify the re-ordering of routes)// Routes can have any data, as long as key and routeName are correct...randomRouteData,},...moreRoutes,]
}

如果router已经在外部处理了acion,或者想不改变任何的navigation state就消化它,这个函数就返回null.

getComponentForRouterName(routeName)

为给定的route name返回子组件或者navigator.
像这样声明一个routergetStateForAction输出的state.

 {index: 1,routes: [{ key: 'A', routeName: 'Foo' },{ key: 'B', routeName: 'Bar' },],
}

基于state中的额routeName,router将会调用router.getComponentForRouteName('Foo')或router.getComponentForRouteName('Bar')来返回对应的有效组件.

 getComponentForState(state)

从深度嵌套navigation state返回激活的组件

 getActionForPathAndParams

返回一个可选配置的navigation action,在用户导航到这个路径并且有可选的查询参数的时候使用这个action.

 getPathAndParamsForState

用户在app中返回同一个URL链接的点时,这个函数返回路径和参数.
从这个函数返回的路径和参数应该是从一个action获得的,这个action是重传进入router的getActionForPathAndParams的.这个action一旦通过getStateForAction传递,会给你返回形似的state.

 getScreenConfig

这个函数从一个route获取navigation的可选项.必须要提供screen的当前navigation prop和被返回的选项的名字.

navigation-这是screen将会使用的navigation prop,对应在screen的route和state.Dispatch将会根据screen的上下文来触发actions.
optionName-被获取的选项的名字,例如’title’

在实例的视图内,或许你需要远程获取配置的标题

 // First, prepare a navigation prop for your child, or re-use one if already available.
const childNavigation = addNavigationHelpers({// In this case we use navigation.state.index because we want the title for the active route.state: navigation.state.routes[navigation.state.index],dispatch: navigation.dispatch,
})
const screenTitle = this.props.router.getScreenConfig(childNavigation, 'title');

StackRouter

管理navigation堆栈的逻辑,包括入栈,出栈,操作路径解析创建深层次的堆栈.

让我们看看简单的stack router

 const MyApp = StackRouter({Home: { screen: HomeScreen },Profile: { screen: ProfileScreen },
}, {initialRouteName: 'Home',
})

RouteConfig

最简单的stack router期待的参数是一个config对象,这里是示例配置

 const MyApp = StackRouter({ // This is the RouteConfig:Home: {screen: HomeScreen,path: '',},Profile: {screen: ProfileScreen,path: 'profile/:name',},Settings {// This can be handy to lazily require a screen:getScreen: () => require('Settings').default,// Note: Child navigators cannot be configured using getScreen because// the router will not be accessible. Navigators must be configured// using `screen: MyNavigator`path: 'settings',},
});

每一个在config中的条目有如下内容

path-设定条目的路径和参数可以在stack中被解析
screen-设定screen组件或者子navigator
getScreen-为screen组件设定惰性加载的设定

StackConfig

配置的选项也被传递进入stack router.

initalRouteName-stack首次加载的默认路由的routeName
initialRouteParams-初始化route的默认参数
paths-提供routeName到path配置的映射,将会重写routeConfigs里的path设置

Supported Actions

stack router可以对下面的导航actions作为响应.如果有可能,router将会代理到子代router的action操作.

Navigate-如果routeName和router的routerConfigs其中之一匹配,将会push一个新的route到堆栈.
Back-返回(props)
Reset-清除堆栈,提供一个新的actions创建新的navigation state
SetParams-screen dispatch一个action去改变当前route的参数

TabRouter

管理应用中的一套tabs,处理tabs之间的跳转,处理back键的操作返回到初始化的tab.
看看简单的tabs router

 const MyApp = TabRouter({Home: { screen: HomeScreen },Settings: { screen: SettingsScreen },
}, {initialRouteName: 'Home',
})

RouteConfig

tabs router有为每一个tab的routeConfig

 const MyApp = TabRouter({ // This is the RouteConfig:Home: {screen: HomeScreen,path: 'main',},Settings: {// This can be handy to lazily require a tab:getScreen: () => require('./SettingsScreen').default,// Note: Child navigators cannot be configured using getScreen because// the router will not be accessible. Navigators must be configured// using `screen: MyNavigator`path: 'settings',},
});

config中的每一个config可能有

config-每一个tab的path
screen-定制screen组件或者子代navigator
getScreen-为一个screen组件设定惰性加载的设置(navigator没有这样的配置)

Tab Router Config

被传递到router的可配置选项

initialRouteName-首次加载的tab的routeName
order-tabs的顺序
path-提供routeName到path config的映射,映射重写routeConfig中的path设定
backBehavior-点击back按钮应该返回到初始化的tab吗？如果是的话,设置initialRoute,否则就是none,默认到initialRoute的行为.