Question

我们使用react-native gifted-chat。有趣的事实是昨天它完美地工作，而今天我们运行模拟器它显示这个奇怪的错误。我们尝试了在模拟器中推荐的解决方案并执行了这3个步骤，但仍然显示相同的错误。怎么解决？这是代码：

import React, {Component } from 'react';
import {
  Platform,
  StyleSheet,
  Text,
  View,
} from 'react-native';

import {GiftedChat, Actions, Bubble, SystemMessage} from 'react-native-gifted-chat';
import CustomActions from '../components/CustomActions';
import CustomView from '../components/CustomView';

export default class MessagesScreen extends React.Component {

  constructor(props) {
    super(props);
    this.state = {
      messages: [],
      loadEarlier: true,
      typingText: null,
      isLoadingEarlier: false,
    };

    this._isMounted = false;
    this.onSend = this.onSend.bind(this);
    this.onReceive = this.onReceive.bind(this);
    this.renderCustomActions = this.renderCustomActions.bind(this);
    this.renderBubble = this.renderBubble.bind(this);
    this.renderSystemMessage = this.renderSystemMessage.bind(this);
    this.renderFooter = this.renderFooter.bind(this);
    this.onLoadEarlier = this.onLoadEarlier.bind(this);

    this._isAlright = null;
  }

  componentWillMount() {
    this._isMounted = true;
    this.setState(() => {
      return {
        messages: require('./data/messages.js'),
      };
    });
  }

  componentWillUnmount() {
    this._isMounted = false;
  }

  onLoadEarlier() {
    this.setState((previousState) => {
      return {
        isLoadingEarlier: true,
      };
    });

    setTimeout(() => {
      if (this._isMounted === true) {
        this.setState((previousState) => {
          return {
            messages: GiftedChat.prepend(previousState.messages, require('./data/old_messages.js')),
            loadEarlier: false,
            isLoadingEarlier: false,
          };
        });
      }
    }, 1000); // simulating network
  }

  onSend(messages = []) {
    this.setState((previousState) => {
      return {
        messages: GiftedChat.append(previousState.messages, messages),
      };
    });

    // for demo purpose
    this.answerDemo(messages);
  }

  answerDemo(messages) {
    if (messages.length > 0) {
      if ((messages[0].image || messages[0].location) || !this._isAlright) {
        this.setState((previousState) => {
          return {
            typingText: 'React Native is typing'
          };
        });
      }
    }

    setTimeout(() => {
      if (this._isMounted === true) {
        if (messages.length > 0) {
          if (messages[0].image) {
            this.onReceive('Nice picture!');
          } else if (messages[0].location) {
            this.onReceive('My favorite place');
          } else {
            if (!this._isAlright) {
              this._isAlright = true;
              this.onReceive('Alright');
            }
          }
        }
      }

      this.setState((previousState) => {
        return {
          typingText: null,
        };
      });
    }, 1000);
  }

  onReceive(text) {
    this.setState((previousState) => {
      return {
        messages: GiftedChat.append(previousState.messages, {
          _id: Math.round(Math.random() * 1000000),
          text: text,
          createdAt: new Date(),
          user: {
            _id: 2,
            name: 'React Native',
            // avatar: 'https://facebook.github.io/react/img/logo_og.png',
          },
        }),
      };
    });
  }

  renderCustomActions(props) {
    if (Platform.OS === 'ios') {
      return (
        <CustomActions
          {...props}
        />
      );
    }
    const options = {
      'Action 1': (props) => {
        alert('option 1');
      },
      'Action 2': (props) => {
        alert('option 2');
      },
      'Cancel': () => {},
    };
    return (
      <Actions
        {...props}
        options={options}
      />
    );
  }

  renderBubble(props) {
    return (
      <Bubble
        {...props}
        wrapperStyle={{
          left: {
            backgroundColor: '#f0f0f0',
          }
        }}
      />
    );
  }

  renderSystemMessage(props) {
    return (
      <SystemMessage
        {...props}
        containerStyle={{
          marginBottom: 15,
        }}
        textStyle={{
          fontSize: 14,
        }}
      />
    );
  }

  renderCustomView(props) {
    return (
      <CustomView
        {...props}
      />
    );
  }

  renderFooter(props) {
    if (this.state.typingText) {
      return (
        <View style={styles.footerContainer}>
          <Text style={styles.footerText}>
            {this.state.typingText}
          </Text>
        </View>
      );
    }
    return null;
  }

  render() {
    return (
      <GiftedChat
        messages={this.state.messages}
        onSend={this.onSend}
        loadEarlier={this.state.loadEarlier}
        onLoadEarlier={this.onLoadEarlier}
        isLoadingEarlier={this.state.isLoadingEarlier}

        user={{
          _id: 1, // sent messages should have same user._id
        }}

        renderActions={this.renderCustomActions}
        renderBubble={this.renderBubble}
        renderSystemMessage={this.renderSystemMessage}
        renderCustomView={this.renderCustomView}
        renderFooter={this.renderFooter}
      />
    );
  }
}

const styles = StyleSheet.create({
  footerContainer: {
    marginTop: 5,
    marginLeft: 10,
    marginRight: 10,
    marginBottom: 10,
  },
  footerText: {
    fontSize: 14,
    color: '#aaa',
  },
});

app.js导航器部分

const Main = StackNavigator(
  {
    Post: {screen: PostScreen},
    Signin: {screen: SigninScreen},
    Signup: {screen: SignupScreen},
    Forgetpass: {screen: ForgetpassScreen},
    Drawer: {screen: Drawer},
    Welcome: {screen: WelcomeScreen},
   Messages: {screen: MessagesScreen},
  },
  {
    initialRouteName: "Signin",
    headerMode: "none",
  },
);

此外，MessagesScreen已在app.js中导入并在react-navigation中实现。正如我所说，昨天完美无缺。虽然现在导致错误。

Answer 1

昨天你可能没有保存就安装了模块，今天你做了一个新的npm install，所以你不再拥有它。您是否可以验证1 react-native-gifted-chat被列为package.json中的依赖项，而react-native-gifted-chat目录下是否存在node_modules？

无法解析模块。文件不存在。关键是，昨天它工作，而今天它显示此错误

1 个答案: