如何使用react native调用子程序中提供程序函数?

xxe27gdn  于 2023-01-02  发布在  React
关注(0)|答案(3)|浏览(139)

我有两个组件。一个是provider,另一个是child。现在我想在child中使用provider函数,但是用我目前的方法,它说函数是未定义的。你能看出我做错了什么吗?下面是代码。

import React from 'react';
import { View, TouchableOpacity, Text } from 'react-native';

const MyProvider = (props) => {
  const { children } = props;
  const handlePress = () => {
    console.log("Provider component function called!");
  };
  return (
    <View>
      {children}
    </View>
  );
};

const NoLocationAccess = (props) => {
  const { handlePress } = props;
  console.log("handlePress : ",handlePress)
  return (
    <TouchableOpacity onPress={handlePress}>
      <Text>I am the child component</Text>
    </TouchableOpacity>
  );
};

export default NoLocationAccess;

我试过provider.wrapper,但问题更多。

bq8i3lrv

bq8i3lrv1#

要从子节点调用在提供程序中定义的函数,您还需要将其作为prop向下传递。
以下是修改后的代码:

import React from 'react';
import { View, TouchableOpacity, Text } from 'react-native';

const MyProvider = (props) => {
  const { children } = props;
  const handlePress = () => {
    console.log("Provider component function called!");
  };
  return (
    <View>
      {React.Children.map(children, (child) => {
        return React.cloneElement(child, { handlePress });
      })}
    </View>
  );
};

const NoLocationAccess = (props) => {
  const { handlePress } = props;
  console.log("handlePress : ",handlePress)
  return (
    <TouchableOpacity onPress={() => handlePress()}>
      <Text>I am the child component</Text>
    </TouchableOpacity>
  );
};

export default NoLocationAccess;

Try it

cbjzeqam

cbjzeqam2#

要将handlePress函数作为 prop 从MyProvider组件传递到NoLocationAccess组件,您需要在传递给NoLocationAccess组件的props中包含handlePress函数。为此,可以使用MyProvider组件中的子属性 Package NoLocationAccess组件,并将handlePress函数作为属性传递给NoLocationAccess组分。
请尝试以下代码。

import React from 'react';
import { View, TouchableOpacity, Text } from 'react-native';

const MyProvider = (props) => {
  const { children } = props;
  const handlePress = () => {
    console.log("Provider component function called!");
  };
  return (
    <View>
      {React.cloneElement(children, { handlePress })}
    </View>
  );
};

const NoLocationAccess = (props) => {
  const { handlePress } = props;
  console.log("handlePress : ",handlePress)
  return (
    <TouchableOpacity onPress={handlePress}>
      <Text>I am the child component</Text>
    </TouchableOpacity>
  );
};

export default NoLocationAccess;
4bbkushb

4bbkushb3#

这花了我一段时间。但我已经做了这个高阶组件。这个想法出现在redux连接方法的脑海中。所以采取了这种方法,并创建了一个高阶组件。这是完美的工作。这里是解决方案。
高阶分量。

import React from 'react';
import { View, TouchableOpacity, Text } from 'react-native';

  
  const MyProvider = (props) => {
    class GPSComponent extends React.Component {
  
        componentDidMount() {
        }
    
        requestPermissions= async()=> {
            console.log("i is called",this.props.userCurrentLocation)
            
        }
    
        render() {
          return <WrappedComponent 
                requestPermissions={this.requestPermissions}
                {...this} 
                />;
        }
      }
    
      return GPSComponent;
    };

子组件。

import React from 'react';
import { View, TouchableOpacity, Text } from 'react-native';
import MyProvider from "./MyProvider"

const NoLocationAccess = (prop) => {
  const { requestPermissions } = prop;
  console.log("requestPermissions ",requestPermissions)

  return (
    <TouchableOpacity onPress={requestPermissions}>
      <Text>I am the child component</Text>
    </TouchableOpacity>
  );
};

export default MyProvider(NoLocationAccess);

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