Why does config.Appsettings.Settings[“MySetting”].Value fail in Windows 7, but not other versions

问题

I'm reading a setting out of the app.config file using code nearly identical to that which I've used in other portions of the app. It works fine under WinXP and Win Server 2003, when I run it under Windows 7 64-bit it generates an exception:

System.NullReferenceException: Object reference not set to an instance of an object.

string exePath = System.IO.Path.Combine(Environment.CurrentDirectory, applicationName);

// Get the configuration file. The file name has this format appname.exe.config.

System.Configuration.Configuration utilConfig = ConfigurationManager.OpenExeConfiguration(exePath);
string fileName = utilConfig.AppSettings.Settings["MsgAlertWav"].Value; //<<Fails here

This is simplified code, but generates the error under Windows 7. It's a .NET 3.0 project compiled for 32-bit target. I have this same code in another module and it works fine under Windows 7.

I am mystified since this code works in one module, but not another and generates no build errors.

回答1:

Try with

System.Configuration.ConfigurationSettings.AppSettings["MsgAlertWav"];

or have a look at the

Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData)

回答2:

System.Configuration.ConfigurationSettings is deprecated and is meant for solutions on framework versions 1.0 and 1.1.

Since you are using a 3.0 you should be using System.Configuration.ConfigurationManager. Is pretty mcuh the same thing, has the same usage

System.Configuration.ConfigurationManager["MsgAlertWav"];

hth, -covo

来源：https://stackoverflow.com/questions/7654780/why-does-config-appsettings-settingsmysetting-value-fail-in-windows-7-but-n