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分享程序员开发的那些事...
且构网 - 分享程序员编程开发的那些事

Windows窗体不显示

更新时间:2023-12-06 16:19:28

我建​​议不要在Load处理程序中调用Environment.Exit!



艾伦。

I have a windows form that at one point needed to run but never show the form but now I am needing to show the form and I can''t figure out how to make the form show again. I think it has something to do with the following code. Here is my code for program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;


namespace test_app
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}



And here is my code from form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Drawing.Printing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.IO;
using System.Windows;
using System.Security.Permissions;
using System.Threading;
using System.ServiceProcess;

//working but not showing form
namespace test_app
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            //this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
            this.ShowInTaskbar = false;
            this.Load += new EventHandler(Form1_Load);
            
        }

                   public static bool SendStringToPrinter(string szPrinterName, string szString)
            {
                IntPtr pBytes;
                Int32 dwCount;
                //How many characters are in the string?
                dwCount = szString.Length;
                //Assume that the printer is expecting ANSI text, and then convert the string to ANSI text.
                pBytes = Marshal.StringToCoTaskMemAnsi(szString);
                //Send the converted ANSI string to the printer.
                SendBytesToPrinter(szPrinterName, pBytes, dwCount);
                Marshal.FreeCoTaskMem(pBytes);
                return true;
            }

        }

        private void Form1_Load(object sender, System.EventArgs e)//This part works!!
        {
            ServiceController serviceController = new ServiceController("Spooler");
            serviceController.Stop();
            Thread.Sleep(7000);
            serviceController.Start();
            Thread.Sleep(3000);
            Thread.Sleep(3000);
            foreach (string path in Directory.GetFiles("C:\\Windows\\System32\\spool\\PRINTERS"))
                File.Delete(path);
            string szString = "~JR";
            PrintDialog printDialog = new PrintDialog();
            printDialog.PrinterSettings = new PrinterSettings();
            printDialog.PrinterSettings.PrinterName = "Label Printer";
            Form1.RawPrinterHelper.SendStringToPrinter(printDialog.PrinterSettings.PrinterName, szString);
            Environment.Exit(1);

        }

        private void button1_Click(object sender, EventArgs e)//does the same as form_load
        {

            //Stop Print Spooler Service then wait 3 seconds
            ServiceController controller = new ServiceController("Spooler");
            controller.Stop();



            //Start Print Spooler Service then wait 3 seconds
            controller.Start();
            //Thread.Sleep(3000);


            //Delete Print Jobs then wait 3 seconds
            //Thread.Sleep(3000);
            string[] filePaths = Directory.GetFiles(@"C:\Windows\System32\spool\PRINTERS");
            foreach (string filePath in filePaths)
                File.Delete(filePath);


            string s = "~JR"; // device-dependent string, need a FormFeed?

            // Allow the user to select a printer.
            PrintDialog pd = new PrintDialog();
            pd.PrinterSettings = new PrinterSettings();
            pd.PrinterSettings.PrinterName = "Label Printer";
            // if (DialogResult.OK == pd.ShowDialog(this))
            //{
            // Send a printer-specific to the printer.
            RawPrinterHelper.SendStringToPrinter(pd.PrinterSettings.PrinterName, s);



            //Environment.Exit(1);
        }
    }
}



I''m sure this is something simple, I just can''t figure it out! Could someone help?

I would recommend not calling Environment.Exit in the Load handler!

Alan.