String copying to clipboard error

Question

I am trying to read a file which include some commands that i want to be copied to clipboard. On searching internet i have found a way how to copy data into clipboard which i have done successfully. However i have to copy multiple commands. which i am doing in a while loop. Here is my code.

{
    class Program
    {
        [DllImport("user32.dll")]
        internal static extern bool OpenClipboard(IntPtr hWndNewOwner);

        [DllImport("user32.dll")]
        internal static extern bool CloseClipboard();

        [DllImport("user32.dll")]
        internal static extern bool SetClipboardData(uint uFormat, IntPtr data);

        [STAThread]
        static void Main(string[] args)
        {
            int counter = 0;
            string line;
            // Read the file and display it line by line.
            System.IO.StreamReader file = new System.IO.StreamReader(@"C:\Users\st4r8_000\Desktop\office work\checks documents\interface check commands.txt");
            OpenClipboard(IntPtr.Zero);
            //int x;
            while((line = file.ReadLine()) != null)
            {
                Console.WriteLine (line);

                //clip board copier

                var yourString = line;
                var ptr = Marshal.StringToHGlobalUni(yourString);
                SetClipboardData(13, ptr);

                Marshal.FreeHGlobal(ptr);
                Console.ReadLine();
                //end of clip board copier
                counter++;
                //ptr = x;

            }
            CloseClipboard();
            file.Close();
            // Suspend the screen.
            Console.ReadLine();
        }
    }
}

So the problem i found is in the following line Marshal.FreeHGlobal(ptr); or may be in SetClipboardData(13, ptr);but i do not know how to resolve this. This runs very fine in the first go but in second or third the program stop responding. Any help will be greatly appreciated.

I am not using windows forms. i am trying to build it in console.

Answer 1

It seems that you don't want all that pInvoke stuff, but Clipboard.SetText:

using System.Windows.Forms; // to have "Clipboard" class
using System.IO;            // to have "File" class

   ...

class Program {

    [STAThread]
    static void Main(string[] args)
    {
        var lines = File.ReadLines(@"C:\Users\st4r8_000\Desktop\office work\checks documents\error log check.txt");

        StringBuilder clipBuffer = new StringBuilder();

        foreach (String line in lines)
        {
            Console.WriteLine(line);

            if (clipBuffer.Length > 0)
                clipBuffer.Append('\n');

            clipBuffer.Append(line);
            Clipboard.SetText(line);
            // Incremental addition; 
            // Clipboard.SetText(line); 
            // if new line should superecede the old one
            //Clipboard.SetText(clipBuffer.ToString());

            Console.ReadLine();
        }
        // Suspend the screen.
        Console.ReadLine();
    }
}