How do i start the block chain using c# code

Question

I am trying to open cmd and through C# code and execute the APIs provided in the documentation. I am able to create a block chain using the 'multichain-util create chain9' but not able to initiate it using the 'multichaind chainName -daemon' command. It shows me the following exception:

IO error: C:\Users\Kishan\AppData\Roaming\MultiChain\chain10\permissions.db\MANIFEST-000002: The handle is invalid.

Below is my source code:

   Process p = new Process();
            p.StartInfo.FileName = "cmd.exe";
            p.StartInfo.WorkingDirectory = @"D:\Work\Blockchain";
            p.StartInfo.CreateNoWindow = true;
            p.StartInfo.RedirectStandardInput = true;
            p.StartInfo.RedirectStandardOutput = true;
            p.StartInfo.UseShellExecute = false;
            p.Start();
            //p.StandardInput.WriteLine("multichain-util create chain10");
            p.StandardInput.WriteLine("multichaind chain10 -daemon");
            //p.StandardInput.WriteLine("cd..");
            p.StandardInput.Flush();
            p.StandardInput.Close();
            p.WaitForExit();
            Console.WriteLine(p.StandardOutput.ReadToEnd());
 

Could you please check on this and provide me with and answer would be really greatful !

Thanks !

Comments

can u send full code for this project because i want to create one simple multichain UI so i need one simple example

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can u send full code for this project because i want to create one simple multichain UI so i need one simple example
i created node but i dont know how to connect multichain to C# UI application

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Sure, I will have it on my github you can clone it from there itself. It would take me a week i guess. So keep trying till then, Will update you once i have it on github !

Answer 1

I think this is what you are seeking.

static void Main(string[] args)
        {

            Process p = new Process();

            p.StartInfo.WorkingDirectory = @"c:\multichain\1.0\";
            p.StartInfo.FileName = @"c:\multichain\1.0\multichaind.exe";
            p.StartInfo.Arguments = "LOTest5 -daemon";
            p.StartInfo.UseShellExecute = false;
            p.StartInfo.RedirectStandardOutput = true;
            
            p.StartInfo.CreateNoWindow = true;
         
            p.OutputDataReceived += P_OutputDataReceived;
          
            p.Start();
            p.BeginOutputReadLine();
            p.WaitForExit();
        }
        
       
        private static void P_OutputDataReceived(object sender, DataReceivedEventArgs e)
        {
            if (e.Data != null)
            {
                Console.WriteLine(e.Data);
            }
        }

Comments

This was helpful, could you think of as why this is happening ?
This worked when I started the chain once but after i terminate the program and again run it. It shows the same error ! This happens with every new chain I create, It starts only once also it terminates it's hosting on its own with the following console message.

Other nodes can connect to this node using:
multichaind chain9@192.168.0.6:9245

Node started
The thread 0x1a28 has exited with code 259 (0x103).
The thread 0x18b0 has exited with code 259 (0x103).
The thread 0x1f08 has exited with code 259 (0x103).

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With p.StartInfo.CreateNoWindow = true; you are not seeing that the process is still running. MultiChaind executable will not exit. It runs and stays running. - You will need to get the Process identifier from the variable in your code and end the process. Even better call Stop method

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Thank You ! This was very helpful.

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I have successfully created a chain and then executed it with code. But till the chain is running i am not able to click on any other button where by i can perform and other operation further like giving permission or any other command that uses multichain-cli. It would be great if you point out the issue i missed !

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disclaimer: the correct means of accesing a node and its json rpc api is NOT executing the multichaincli exe within a process..

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Could you guide how to do it ? Do I need to use any library, which would have methods using which we can access the JSON RPC API. Could you help a little ?