C# SharePoint CSOM change file properties after upload - sharepoint

Question

I have searched and found several examples of how to do this, but I can't make them work - well part of it doesn't work.
I can perform the file upload, but the following attempt to change properties fail.
I'm attempting to upload a file from a base64 payload - this part works - but when I afterwards attempt to edit the properties (custom column) associated with the file, the code fails.
Here is the code (simplified for readability):
(note that props is a collection of custom objects (FileProperty) with a name and a value attribute).
using (ClientContext context = new ClientContext("<sharepoint_server_url>"))
{
context.Credentials = new SharePointOnlineCredentials(<usr>,<secure_pwd>);
using (System.IO.MemoryStream ms = new System.IO.MemoryStream(Convert.FromBase64String(<base64_content>)))
{
File.SaveBinaryDirect(context, <relative_path>, ms, true);
}
// file is uploaded - so far so good!
// attempt to edit properties of the file.
if (props != null)
{
if (props.Count > 0)
{
File newFile = context.Web.GetFileByServerRelativeUrl(<relative_path>);
context.Load(newFile);
context.ExecuteQuery();
newFile.CheckOut();
ListItem item = newFile.ListItemAllFields;
foreach (FileProperty fp in props)
{
item[fp.name] = fp.value;
}
item.Update();
newFile.CheckIn(string.Empty, CheckinType.OverwriteCheckIn);
}
}
}
This code throws an exception in the part where I try to update the properties.
Message: The file was not found.
Can anyone tell me what is wrong with this example or provide another example on how to do this?
Also, a question - is there a way to address a file by a unique ID which is the same regardless of where in the SharePoint server the file is located or moved to?
I hope someone can help me out - thanks :)

Answer 1

Ok, I found a solution to my problem. I don't know why this works better, it just does.
For all I know, I'm doing the exact same thing, just in another way - maybe someone else who knows more about SharePoint than me (which isn't much) can explain why this works while the first example I posted doesn't.
Previous to the code shown, I ensure that <site_url> doesn't end with "/" and that <library_name> doesn't start or end with "/" and that <file_name> doesn't start or end with "/".
With the code below I can uplaod a file and update properties, in my case i changed "Title" and a custom column "CustCulomnA" and it workes.
using (ClientContext context = new ClientContext(<site_url>))
{
context.Credentials = new SharePointOnlineCredentials(<usr>, <secure_pwd>);
FileCreationInformation fci = new FileCreationInformation()
{
Url = <file_name>,
Content = Convert.FromBase64String(<base64_content>),
Overwrite = true
};
Web web = context.Web;
List lib = web.Lists.GetByTitle(<library_name>);
lib.RootFolder.Files.Add(fci);
context.ExecuteQuery();
response.message = "uploaded";
if (props != null)
{
if (props.Count > 0)
{
File newFile = context.Web.GetFileByUrl(<site_url> +"/"+ <library_name> + "/" + <file_name>);
context.Load(newFile);
context.ExecuteQuery();
newFile.CheckOut();
ListItem item = newFile.ListItemAllFields;
foreach (FileProperty fp in props)
{
item[fp.name] = fp.value;
}
item.Update();
newFile.CheckIn(string.Empty, CheckinType.OverwriteCheckIn);
context.ExecuteQuery();

Answer 2

Make sure the file server relative url is valid in this case.
For example if the complete url is:
https://zheguo.sharepoint.com/sites/test/Shared%20Documents/test.jpg
Then relative url should be
/sites/test/Shared%20Documents/test.jpg
And you can also use GetFileByUrl method, passing the complete file url like this:
clientContext.Credentials = new SharePointOnlineCredentials(userName, securePassword);
Web web = clientContext.Web;
clientContext.Load(web);
clientContext.ExecuteQuery();
File file = web.GetFileByUrl("https://zheguo.sharepoint.com/sites/test/Shared%20Documents/test.jpg");
clientContext.Load(file);
clientContext.ExecuteQuery();
file.CheckOut();
ListItem item = file.ListItemAllFields;
item["Title"] = "Test";
item.Update();
file.CheckIn(string.Empty, CheckinType.OverwriteCheckIn);
clientContext.ExecuteQuery();
}