react-native中常用到的一些解决问题方法（整理一些真正有效能够使用到项目中的方法）（等待不断更新积累）

我会带着你远行 2022-03-26 09:30 173阅读 0赞

*  判断当前设备环境

开头引入

import { Platform } from 'react-native';

中间内容区域加上如下判断

if(Platform.OS === "android") {
       //Android平台需要运行的代码
       alert("当前是Android系统。");
    }else{
       //iOS平台需要运行的代码
       alert("当前是iOS系统。");
    }

*  react-native-vector-icons在android上图标不能显示的问题

npm link,然后重新run-android一下能解决

*   null is not an object (evaluating 'rngesturehandlermodule.state')

npm install --save react-native-gesture-handler
    react-native link

*  Cannot read property 'oneOf' of undefined

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70][]

将import \{PropTypes\} from 'react-native' 修改为import PropTypes from 'prop-types'

*  No bundle url present

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70 1][]

退出程序，重启即可

若重启无法解决，再开一个窗口，输入npm start，然后返回原先的1:bash，再次重启

![20190419101428991.png][]

*  React Native Error: Unable to resolve module \`./index\`

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70 2][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70 3][]

将之前打开的那个程序关闭即可

watchman watch-del-all
    npm start -- --reset-cache

严重的时候，甚至需要重装依赖, 更严重是时候竟然要重新生成 android 和 ios 项目:

rm -rf node_modules && cnpm i  // 重装依赖
    rm -rf ios                     // 重新生成项目
    rm -rf android
    react-native upgrade

*  application has not been registered

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70 4][]

找到之前开启了npm start的项目，然后ctrl+c

*  Failed to install the following Android SDK packages as some licences have not been accepted.

![20190422211716240.png][]

解决方法：

![20190422232450510.png][]

点击之后，弹出窗口，点击accept，等待安装完成，成功解决

*  "Signing for "...你的项目名" requires a development team. Select a development team in the project editor."

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70 5][]

用你的aplleid创建开发账号，如果只是学习，不建议

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70 6][]

学习，建议方法：

1.npm start

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70 7][]

2.再返回到1:bash中重启项目

![2019043009530820.png][]

*  当修改原生组件Java代码

我想引入format,date,calendar等获取今天、昨天的日期，需要在开头引入

import java.text.SimpleDateFormat;
    import java.util.Date;
    import java.text.ParseException;
    import java.util.Calendar;

然后格式化日期

SimpleDateFormat formatDate = new SimpleDateFormat("YYYY-MM-DD");
    Date today = new Date(); // 创建一个Date对象，获取当前时间
    String todayFormat = formatDate.format(today);
    // 创建一个Calendar对象，获取昨天时间
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(new Date());  
    calendar.add(calendar.DATE,-1);
    String yesterday = formatDate.format(calendar.getTime());

然后我又想对获取的数据进行格式化，结果报错：Cannot format given Object as a Date

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[20190419101428991.png]: /images/20220326/dab8f80b78754c95bcff5f197e5498c4.png
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70 3]: /images/20220326/967d769e1fe34e0bbdb34a3ebee6d138.png
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[20190422211716240.png]: /images/20220326/03e45fce14834a59b4e116f2e72d31ed.png
[20190422232450510.png]: /images/20220326/42fbafadc3fa4468bbaf32fde6c985fc.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70 5]: /images/20220326/a5523fb1f33d40cc93c4e8f10d4a4847.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3ODE1NTk2_size_16_color_FFFFFF_t_70 6]: /images/20220326/3a729760748f485da4069cd03b6ba175.png
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[2019043009530820.png]: /images/20220326/f54d8d7a51f74dd1b6f0f7a2ed02a059.png