CODEWITHSUNDEEP
c#
Foertsch
Foertsch

Reputation: 115

Overwriting a txt file

I have a problem writing the file: I call the app launch via the API and get its status in string.

using System;
using System.Threading.Tasks;
using UiPath.Robot.Api;
using System.Linq;
using System.IO;

namespace RobotApi
{
    class Program
    {
        static TextWriter sw = new StreamWriter("d:\\robo\\log.txt", true, System.Text.Encoding.Default);
        static async Task Main(string[] args)
        {
            var client = new RobotClient();
            
            var processes = await client.GetProcesses();
            var myProcess = processes.Single(process => process.Name == "MyProcess");
            var job = myProcess.ToJob();

            job.StatusChanged += (sender, args) => sw.WriteLine($"{((Job)sender).ProcessKey}: {args.Status}");
            await client.RunJob(job);
        }
    }
}

I need to write the job status to a txt file for later analysis. Since the program is called asynchronously, I can't use the StreamWritter, since it simply can't be closed. File.WriteAllText just can't handle such a flow of information and doesn't have time to close the file, as a result, I get an error message that txt is being used by another process.

Please tell me, is there a way to write a large stream of information to a txt file in my case (it is necessary that the string is overwritten with each status update)?

Upvotes: 1

Views: 109

Answers (2)

Thomas Weller
Thomas Weller

Reputation: 59208

I believe that your problem is just with the lambda expression and you don't know how to get more statements inside it except the WriteLine() call.

A solution would be to define a regular method instead of the lambda expression.

namespace RobotApi
{
    class Program
    {
        // <-- removed the StreamWriter here
        static async Task Main(string[] args)
        {
            var client = new RobotClient();
            
            var processes = await client.GetProcesses();
            var myProcess = processes.Single(process => process.Name == "MyProcess");
            var job = myProcess.ToJob();

            job.StatusChanged += OnStatusChanged;   // <-- refer to the method here
            await client.RunJob(job);
        }

        // This method is new
        // Assuming StatusEventArgs
        void OnStatusChanged(object sender, StatusEventArgs args)
        {
            // using will close the file
            using (TextWriter sw = new StreamWriter("d:\\robo\\log.txt", true, System.Text.Encoding.Default))
            {
                sw.WriteLine($"{((Job)sender).ProcessKey}: {args.Status}");
            }
        }
    }
}

This implementation is not thread safe, but your implementation wasn't either, so I don't care at the moment.

Upvotes: 2

Bob Logan
Bob Logan

Reputation: 46

sw (from TextWriter) is statically global to the program object... I do not see where it is being CLOSED... you write to it on the async threading calls... but never close it... never flush it...

And of course (unless I missed something) never overwrite it with a new open call... so there is never the intended overwrite????

Upvotes: 1

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