用于在特定文件夹C＃中查找特定文件的自定义路径

Question

I want to look up at the database's file in the specific folder and what I did before is like this:

"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:/Fuhans's Folder/Project/SIA - Point of Sales/SIA - Point of Sales/Assets/Database/db1.accdb; Persist Security Info=False;";

and I am thinking that is there a shortcut way to look up the database's file, instead of writing a specific folder?

and I came up with:

"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=../Assets/Database/db1.accdb; Persist Security Info=False;";

But, when I changed it into like the second one, the error message appear like below:

My question is: Is there a way to delete the bin location path, but still doing the look up the database's file like the second one?

Thank you

Answer 1

在相对路径前面添加另一个../ ：

"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=../../Assets/Database/db1.accdb; Persist Security Info=False;";

Answer 2

You should avoid to use absolute paths in your connection string and relative paths (with .. are pretty easy to be broken when you deploy).

In ASP.NET to use a relative path you may use |DataDirectory|db1.accdb , in WinForms it's not available but that constants are resolved using Application Domain properties. Simply set your base bath inside your main() method:

AppDomain.Current.SetData("RootFolder",
    @"D:\Fuhans's Folder\Project\SIA - Point of Sales\SIA - Point of Sales");

And your connection string:

Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|RootFolder|Assets/Database/db1.accdb;

Why you should use an absolute path instead of a relative one? Because it won't be affected by working directory and it's easier to add multiple constants:

AppDomain.Current.SetData("Bin",
    Application.StartupPath);
AppDomain.Current.SetData("AppData",
    Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData));

Second option will work much better with UAC (where program's folder may not be writeable at all). Also note that path is still navigable because it'll be normalized.

Assuming your compiling to bin/debug in your development environment:

Data Source=|Bin|../../Assets/Database/db1.accdb

Assuming your application will be deployed and it'll work on data folder (not program folder):

Data Source=|AppData|Assets/Database/db1.accdb

Straight and easy.