ASP.NET Core 找不到 npm指令异常

1.错误再现

利用VS2019预览版创建ASP.NET Core 的单页面Web程序

创建后直接运行，出现如下错误

Ensure that 'npm' is installed and can be found in one of the PATH directories.

ASP.NET Core 找不到 npm指令异常

2.相关资料

找到以下资料

https://github.com/aspnet/AspNetCore/issues/5263

https://github.com/aspnet/AspNetCore.Docs/blob/master/aspnetcore/host-and-deploy/aspnet-core-module/samples_snapshot/2.x/CurrentDirectoryHelpers.cs

3.解决方案

添加类CurrentDirectoryHelpers，代码如下

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WebApplication6
{
    public class CurrentDirectoryHelpers
    {
        internal const string AspNetCoreModuleDll = "aspnetcorev2_inprocess.dll";

        [System.Runtime.InteropServices.DllImport("kernel32.dll")]
        private static extern IntPtr GetModuleHandle(string lpModuleName);

        [System.Runtime.InteropServices.DllImport(AspNetCoreModuleDll)]
        private static extern int http_get_application_properties(ref IISConfigurationData iiConfigData);

        [System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
        private struct IISConfigurationData
        {
            public IntPtr pNativeApplication;
            [System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.BStr)]
            public string pwzFullApplicationPath;
            [System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.BStr)]
            public string pwzVirtualApplicationPath;
            public bool fWindowsAuthEnabled;
            public bool fBasicAuthEnabled;
            public bool fAnonymousAuthEnable;
        }

        public static void SetCurrentDirectory()
        {
            try
            {
                // Check if physical path was provided by ANCM
                var sitePhysicalPath = Environment.GetEnvironmentVariable("ASPNETCORE_IIS_PHYSICAL_PATH");
                if (string.IsNullOrEmpty(sitePhysicalPath))
                {
                    // Skip if not running ANCM InProcess
                    if (GetModuleHandle(AspNetCoreModuleDll) == IntPtr.Zero)
                    {
                        return;
                    }

                    IISConfigurationData configurationData = default(IISConfigurationData);
                    if (http_get_application_properties(ref configurationData) != 0)
                    {
                        return;
                    }

                    sitePhysicalPath = configurationData.pwzFullApplicationPath;
                }

                Environment.CurrentDirectory = sitePhysicalPath;
            }
            catch
            {
                // ignore
            }
        }
    }
}

View Code

在Main方法中调用

ASP.NET Core 找不到 npm指令异常

运行，发现神奇般的好啦！！！