.netcore入门

开发环境：windows    编辑器： Visual Studio Code

环境安装：

.Net Core 1.1 SDK     https://www.microsoft.com/net/core#windowscmd

1.新建控制台项目（参考：https://docs.microsoft.com/en-us/dotnet/articles/core/tutorials/using-with-xplat-cli）

1.1 安装.Net Core 1.1 SDK完成后，打开cmd命令窗口，输入dotnet，可以看到如下，说明安装成功

E:\lindy\netcoreproject\aspnetcoreapp>dotnet
 
Microsoft .NET Core Shared Framework Host
 
  Version  : 1.1.0
  Build    : 928f77c4bc3f49d892459992fb6e1d5542cb5e86
 
Usage: dotnet [common-options] [[options] path-to-application]
 
Common Options:
  --help                           Display .NET Core Shared Framework Host help.
 
  --version                        Display .NET Core Shared Framework Host versi
on.
 
Options:
  --fx-version <version>           Version of the installed Shared Framework to
use to run the application.
  --additionalprobingpath <path>   Path containing probing policy and assemblies
 to probe for.
 
Path to Application:
  The path to a .NET Core managed application, dll or exe file to execute.
 
If you are debugging the Shared Framework Host, set 'COREHOST_TRACE' to '1' in y
our environment.
 
To get started on developing applications for .NET Core, install the SDK from:
  http://go.microsoft.com/fwlink/?LinkID=798306&clcid=0x409

1.2.输入以下命令，可以看到在hwapp目录下创建了一个控制台项目,cmd控制台窗口可看到“Hello World!"输出

mkdir hwapp
cd hwapp
dotnet new
dotnet restore
dotnet run

1.3 在vscode下调试项目

用vscode打开hwapp文件夹；在扩展菜单那里找到C#扩展，并安装 ；点击调试菜单，并点击设置栏，选择.net core作为debug环境；打开program.cs文件，点击开始调试（F5），运行可看到调试控制台“Hello World!"输出（ps:默认调试当前打开文件）

2.新建asp.net core程序（https://docs.microsoft.com/zh-cn/aspnet/core/getting-started）

2.1 新建项目

mkdir aspnetcoreapp

cd aspnetcoreapp

dotnet new –t web

2.2 恢复包文件（ps：nuget包默认路径，在当前用户下的.nuget文件夹里，例如C:\Users\lindanyang\.nuget，即我们加载的nuget包都在此路径下）

dotnet restore

此处可能由于被墙的原因，会报如下错误：

error: Failed to retrieve information from remote source 'http://go.microsoft.co
m/fwlink/?LinkID=206669/FindPackagesById()?id='Microsoft.AspNetCore.Diagnostics.
EntityFrameworkCore''.
error: Response status code does not indicate success: 301 (Moved Permanently).

解决方法，在项目路径下添加 NuGet.config 文件，添加nuget源

配置如下：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
<packageSources>
<!--To inherit the global NuGet package sources remove the <clear/> line below -->
<clear />
<add key="dotnet-core" value="https://dotnet.myget.org/F/dotnet-core/api/v3/index.json" />
<add key="api.nuget.org" value="https://api.nuget.org/v3/index.json" />
<add key="AspNetCI" value="https://www.myget.org/F/aspnetcirelease/api/v3/index.json" />
</packageSources>
</configuration>

2.3 运行网站

dotnet run

.net core版本配置问题也可能导致如下错误：

The specified framework 'Microsoft.NETCore.App', version '1.1.0-preview1-001153-
00' was not found.
- Check application dependencies and target a framework version installed at:
C:\Program Files\dotnet\shared\Microsoft.NETCore.App
- The following versions are installed:
1.1.0
- Alternatively, install the framework version '1.1.0-preview1-001153-00'.

解决方法：

根据dotnet命令获取.net core版本，修改project.json文件的.net core版本Version，如果nuget包的相关版本不对，也要修改：

  "userSecretsId": "aspnet-WebApplication-0799fe3e-6eaf-4c5f-b40e-7c6bfd5dfa9a",
 
  "dependencies": {
    "Microsoft.NETCore.App": {
      "version": "1.1.0",
      "type": "platform"
    },

保存后再次执行  dotnet restore   和  dotnet run 命令

2.4 打开网站，如下图所示

http://localhost:5000/

2.5  项目文件下有README.md 文件，里面有web项目相关操作的教程网址，可以进一步学习

2.6  vscode操作：vscode操作部分和控制台程序一致，有以下差异：

（1）配置启动程序dll路径，即配置launch.json为如下路径：在name为.NET Core Launch (web)处配置program为${workspaceRoot}/bin/Debug/netcoreapp1.1/aspnetcoreapp.dll

 {
            "name": ".NET Core Launch (web)",
            "type": "coreclr",
            "request": "launch",
            "preLaunchTask": "build",
            "program": "${workspaceRoot}/bin/Debug/netcoreapp1.1/aspnetcoreapp.dll",
            "args": [],
            "cwd": "${workspaceRoot}",
            "stopAtEntry": false,
            "launchBrowser": {
                "enabled": true,
                "args": "${auto-detect-url}",
                "windows": {
                    "command": "cmd.exe",
                    "args": "/C start ${auto-detect-url}"
                },
                "osx": {
                    "command": "open"
                },
                "linux": {
                    "command": "xdg-open"
                }
            },
            "env": {
                "ASPNETCORE_ENVIRONMENT": "Development"
            },
            "sourceFileMap": {
                "/Views": "${workspaceRoot}/Views"
            }
        }

（2）注意把之前用dotnet run命令启动的网站停掉:Ctrl+C,否则会报错

（3）注意到\Views\Shared\_Layout.cshtml文件引用的css和js文件并没有在文件夹里，需要另外下载加到路径里，之前dotnet run命令引用到的文件在

<environment names="Staging,Production">标签里，而vscode是开发模式，引用的文件在<environment names="Development">里，而

~/lib/bootstrap/dist/css/bootstrap.css在项目文件夹里并没有，需要自己另外下载，其他的js文件也一样。

<environment names="Development">
        <link rel="stylesheet" href="~/lib/bootstrap/dist/css/bootstrap.css" />
        <link rel="stylesheet" href="~/css/site.css" />
    </environment>
    <environment names="Staging,Production">
        <link rel="stylesheet" href="https://ajax.aspnetcdn.com/ajax/bootstrap/3.3.6/css/bootstrap.min.css"
              asp-fallback-href="~/lib/bootstrap/dist/css/bootstrap.min.css"
              asp-fallback-test-class="sr-only" asp-fallback-test-property="position" asp-fallback-test-value="absolute" />
        <link rel="stylesheet" href="~/css/site.min.css" asp-append-version="true" />
    </environment>

ps:其他详细配置和多项目程序待研究

补充：多项目程序 ：http://www.cnblogs.com/ldybyz/p/6483571.html