# 使用Devtools工具调试前端页面


Web组件支持使用DevTools工具调试前端页面。DevTools是一个 Web前端开发调试工具，提供了电脑上调试移动设备前端页面的能力。开发者通过[setWebDebuggingAccess()](../reference/apis-arkweb/js-apis-webview.md#setwebdebuggingaccess)接口开启Web组件前端页面调试能力，利用DevTools工具可以在电脑上调试移动设备上的前端网页，设备需为4.1.0及以上版本。


使用DevTools工具，可以执行以下步骤：


1. 在应用代码中开启Web调试开关，具体如下：

   ```ts
   // xxx.ets
   import { webview } from '@kit.ArkWeb';

   @Entry
   @Component
   struct WebComponent {
     controller: webview.WebviewController = new webview.WebviewController();

     aboutToAppear() {
       // 配置Web开启调试模式
       webview.WebviewController.setWebDebuggingAccess(true);
     }
 
     build() {
       Column() {
         Web({ src: 'www.example.com', controller: this.controller })
       }
     }
   }
   ```
2. 开启调试功能需要在DevEco Studio应用工程hap模块的module.json5文件中增加如下权限，添加方法请参考[在配置文件中声明权限](../security/AccessToken/declare-permissions.md)。

   ```
   "requestPermissions":[
      {
        "name" : "ohos.permission.INTERNET"
      }
    ]
   ```

3. 将设备连接上电脑，在电脑端配置端口映射，配置方法如下：

   ```
   //查找 devtools 远程调试所需的 domain socket 名称，该名称与进程号有关，重启调试应用后，需要重复此步骤，以完成端口转发
   cat /proc/net/unix | grep devtools
   // 添加映射 [pid] 替换成实际的进程id
   hdc fport tcp:9222 localabstract:webview_devtools_remote_[pid]
   // 查看映射 
   hdc fport ls
   示例：
   hdc shell
   cat /proc/net/unix | grep devtools
   //显示 webview_devtools_remote_3458
   exit
   hdc fport tcp:9222 localabstract:webview_devtools_remote_3458
   hdc fport ls
   ```

4. 在电脑端Chrome浏览器地址栏中输入chrome://inspect/\#devices，页面识别到设备后，就可以开始页面调试。调试效果如下：

     **图1** 页面调试效果图  

     ![debug-effect](figures/debug-effect.png)


5. 多应用调试请在调试地址内Devices中的configure添加多个端口号以同时调试多个应用：

     **图2** 添加端口号效果图  

     ![debug-effect](figures/debug-domains.png)

6. windows便捷脚本，请复制以下信息建立bat文件，开启调试应用后执行：

   ```
   @echo off
   setlocal enabledelayedexpansion

   :: Initialize port number and PID list
   set PORT=9222
   set PID_LIST=

   :: Get the list of all forwarded ports and PIDs
   for /f "tokens=2,5 delims=:_" %%a in ('hdc fport ls') do (
       if %%a gtr !PORT! (
           set PORT=%%a
       )
       for /f "tokens=1 delims= " %%c in ("%%b") do (
           set PID_LIST=!PID_LIST! %%c
       )
   )

   :: Increment port number for next application
   set temp_PORT=!PORT!
   set /a temp_PORT+=1  
   set PORT=!temp_PORT! 

   :: Get the domain socket name of devtools
   for /f "tokens=*" %%a in ('hdc shell "cat /proc/net/unix | grep devtools"') do (
       set SOCKET_NAME=%%a

       :: Extract process ID
       for /f "delims=_ tokens=4" %%b in ("!SOCKET_NAME!") do set PID=%%b
 
       :: Check if PID already has a mapping
       echo !PID_LIST! | findstr /C:" !PID! " >nul
       if errorlevel 1 (
           :: Add mapping
           hdc fport tcp:!PORT! localabstract:webview_devtools_remote_!PID!
           if errorlevel 1 (
               echo Error: Failed to add mapping.
               pause
               exit /b
           )

           :: Add PID to list and increment port number for next application 
           set PID_LIST=!PID_LIST! !PID!
           set temp_PORT=!PORT!
           set /a temp_PORT+=1  
           set PORT=!temp_PORT! 
       )
   )

   :: If no process ID was found, prompt the user to open debugging in their application code and provide the documentation link
   if "!SOCKET_NAME!"=="" (
       echo No process ID was found. Please open debugging in your application code using the corresponding interface. You can find the relevant documentation at this link: [https://gitee.com/openharmony/docs/blob/master/zh-cn/application-dev/web/web-debugging-with-devtools.md]
       pause
       exit /b
   )

   :: Check mapping
   hdc fport ls

   echo.
   echo Script executed successfully. Press any key to exit...
   pause >nul

   :: Try to open the page in Edge
   start msedge chrome://inspect/#devices.com

   :: If Edge is not available, then open the page in Chrome
   if errorlevel 1 (
       start chrome chrome://inspect/#devices.com
   )

   endlocal
   ```

7. mac/linux便捷脚本，请复制以下信息建立sh文件，请自行注意chmod以及格式转换，开启调试应用后执行：
   ```
   #!/bin/bash

   # Initial port number
   INITIAL_PORT=9222
    
   # Get the current port number, use initial port number if not set previously
   CURRENT_PORT=${PORT:-$INITIAL_PORT}

   # Get the list of all PIDs that match the condition
   PID_LIST=$(hdc shell cat /proc/net/unix | grep webview_devtools_remote_ | awk -F '_' '{print $NF}')

   if [ -z "$PID_LIST" ]; then
       echo "Failed to retrieve PID from the device"
       exit 1
   fi

   # Increment the port number
   PORT=$CURRENT_PORT

   # Forward ports for each application one by one
   for PID in $PID_LIST; do
       # Increment the port number
       PORT=$((PORT + 1))

       # Execute the hdc fport command
       hdc fport tcp:$PORT localabstract:webview_devtools_remote_$PID
    
       # Check if the command executed successfully
       if [ $? -ne 0 ]; then
           echo "Failed to execute hdc fport command"
           exit 1
       fi
   done

   # List all forwarded ports
   hdc fport ls
   ```