Hi,
I have .Net 3.5 SP1 click once application. The application reads/writes files in subfolders beneath the folder the application is executing from. I noticed that Clickonce installation of new client versions places the executable in random folder. This effectively disconnects the new version from previous data.In my case, this is not desireable. What is the standard pattern for maintaining connection to usersfiles for click once client applications?

Hi m6rk,

I think there are two options for you.

1. You can mark the files as data files. When new versions of the Applications were installed, all the existing data on the previous version's data directory will be copied to the current version's data directory. See this page for more detail.
2. Store the files in a common location in the machine. That is store the files on the Application Data Directory. See this page for how to get the path of the Application Data Directory.

If you have any doubts, please feel free to contact me.

Best regards,
Bruce Zhou

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Please mark the replies as answers if they help and unmark if they don't.

Hi, m6rk.

We create a folder under LocalApplicationData with the name of our company, and cache files there that we don't want impacted by updates. Note that they will also remain after the user uninstalls the app, which is good and bad. It's good in case they are uninstalling and reinstalling for some reason, but it's bad if you care that you're leaving them behind if they just uninstall.

To get to that folder:

string userFilePath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);

So you might do something like this:

string wheresMyDataFolder = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "mycompanyname");

When you run our application, it checks to see if the Folder with our company name exists, and if it doesn't, we create it and copy the files over there. If the Folder is there, we still check for each file and copy them over if they don't exist. After the first time, everything will exist, and it won't override them unless you specifically code for that.

You will want to add the files to your project, mark them with a build action of "content" and a "copy to output directory" value of "copy always", to make sure they get deployed. They end up in System.Windows.Forms.Application.StartupPath, so you can just copy them from there.

RobinDotNet

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Click here to visit my ClickOnce blog!

Hi m6rk,

I think there are two options for you.

1. You can mark the files as data files. When new versions of the Applications were installed, all the existing data on the previous version's data directory will be copied to the current version's data directory. See this page for more detail.
2. Store the files in a common location in the machine. That is store the files on the Application Data Directory. See this page for how to get the path of the Application Data Directory.

If you have any doubts, please feel free to contact me.

Best regards,
Bruce Zhou

---

Please mark the replies as answers if they help and unmark if they don't.

Hi, m6rk.

We create a folder under LocalApplicationData with the name of our company, and cache files there that we don't want impacted by updates. Note that they will also remain after the user uninstalls the app, which is good and bad. It's good in case they are uninstalling and reinstalling for some reason, but it's bad if you care that you're leaving them behind if they just uninstall.

To get to that folder:

string userFilePath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);

So you might do something like this:

string wheresMyDataFolder = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "mycompanyname");

When you run our application, it checks to see if the Folder with our company name exists, and if it doesn't, we create it and copy the files over there. If the Folder is there, we still check for each file and copy them over if they don't exist. After the first time, everything will exist, and it won't override them unless you specifically code for that.

You will want to add the files to your project, mark them with a build action of "content" and a "copy to output directory" value of "copy always", to make sure they get deployed. They end up in System.Windows.Forms.Application.StartupPath, so you can just copy them from there.

RobinDotNet

---

Click here to visit my ClickOnce blog!

Thank you both. This is exactly the information I was looking for.