无法在控制台应用程序中从 appsettings.json 读取连接字符串

Question

我正在使用控制台应用程序测试 .NET 核心，但我一直在阅读 appsettings.json。这是我的代码：

{
    "ConnectionStrings": {
        "DataBaseConnectionString": "Server=xxxxxx"
        }
}

...

var builder = new ConfigurationBuilder()
    //  .SetBasePath("")
    .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
    .AddEnvironmentVariables();
configuration = builder.Build();

var xx = configuration.GetConnectionString("DataBaseConnectionString");

我在 xx 上得到了 null，我做错了什么？谢谢

Answer 1

您的代码是正确的。设置 optional: false 以检查文件是否存在。控制台应用程序的关键点是确保 appsettings.json 有 Copy to output directory: Always 属性。

这是一个最小的可重现示例：

//set "optional: false" to fail-fast without a file
var builder = new ConfigurationBuilder().AddJsonFile("appsettings.json", optional: false);
var configuration = builder.Build();

//contains "Server=xxxxxx"
string str = configuration.GetConnectionString("DataBaseConnectionString");

实际文档：Configuration in ASP.NET Core

无法在控制台应用程序中从 appsettings.json 读取连接字符串

Unable to read connection string from appsettings.json in a console application

c#

.net-core