Question

尝试从React-Navigation实施Navigators时，我遇到了一些奇怪的行为。

从https://reactnavigation.org/docs/en/hello-react-navigation.html ...

尝试简单的“hello world”时

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

class HomeScreen extends React.Component {
  render() {
    return (
      <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
        <Text>Home Screen</Text>
      </View>
    );
  }
}

export default createStackNavigator({
  Home: {
    screen: HomeScreen,
  },
});

我收到此错误：

不变违规：元素类型无效：期望一个字符串（对于内置组件）或一个类/函数（对于复合组件）但得到：object。检查'SceneView'的渲染方法。

奇怪的是，当使用StackNavigator（和TabNavigator）给我不可侵犯时，使用DrawerNavigator不会！

This common fix (removing the braces in the import) gives a new error：

对象不是函数

And the common fix to "Object is not a function" leads me back to where I started (adding braces to the import).

我是React-Native的新手，不知道如何深入研究这个问题，感谢任何帮助！

- - - - 修改 -----

我已将我的react-navigation版本降级到v1.5.5并且原始StackNavigator组件正常工作，所以这可能与v2.0.1和我的环境存在兼容性问题。

Answer 1

如果您的Sub Connection() Dim Conn As ADODB.Connection Dim Command As ADODB.Command Set Conn = New ADODB.Connection Set Command = New ADODB.Command Dim i As Integer Dim rownumber As Integer rownumber = Sheets("Sheet1").Range("A1048576").End(xlUp).Row Conn.ConnectionString = "Provider=SQLOLEDB; Data Source=[Server];Initial Catalog=[DB];User ID=[user];Password=[Password]; Trusted_Connection=no" Conn.Open Command.ActiveConnection = Conn For i = 1 To rownumber 'rows If ActiveSheet.Cells(i, 8).Value = "Y" Then GoTo NextIteration Else Command.CommandText = "INSERT INTO [Database] (" & _ "[Col1], [Col2], [Col3], [Col4], [Col5], [Col6], [Col7])" & _ "VALUES (" & _ "'" & ActiveSheet.Cells(i, 1).Value & "'," & _ "'" & ActiveSheet.Cells(i, 2).Value & "'," & _ "'" & ActiveSheet.Cells(i, 3).Value & "'," & _ "'" & ActiveSheet.Cells(i, 4).Value & "'," & _ "'" & ActiveSheet.Cells(i, 5).Value & "'," & _ "'" & ActiveSheet.Cells(i, 6).Value & "'," & _ "'" & ActiveSheet.Cells(i, 7).Value & "')" Command.Execute ActiveSheet.Cells(i, 8).Value = "Y" End If Next i Conn.Close Set Conn = Nothing End Sub拥有正确的react版本，请检入package.json。例如，

react-native

不适合我，但是

"react": "16.4.0",
"react-native": "^0.53",
"react-navigation": "^2.0.4",

作品。

Answer 2

我可能已经找到了你的问题。我认为您正在尝试按照错误版本的文档进行操作。我假设你正在使用反应导航的V1。

您可以通过在项目根目录中的终端中运行“yarn list react-navigation”来查看当前安装的版本。

V1文档：https://v1.reactnavigation.org/docs/hello-react-navigation.html

如果我使用上面链接中的示例，一切正常。也许你可以尝试一下？

标记

仅使用一些导航器的不变违规（React-Navigation）

2 个答案: