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Sampel Penanganan Aktivitas (POS untuk Dokumentasi .NET v1.14 SDK)

Sampel ini menunjukkan bagaimana aplikasi dapat mendaftarkan handler untuk salah satu dari lima jenis peristiwa yang didukung oleh Microsoft Point of Service untuk .NET (POS untuk .NET):

  • DataEvent
  • ErrorEvent
  • StatusUpdateEvent
  • OutputCompleteEvent
  • DirectIOEvent

Ini juga menunjukkan bagaimana aplikasi mengelola permintaan output asinkron ke PosPrinter perangkat.

Untuk membuat proyek sampel

  1. Kompilasi dan instal kode sampel Objek Layanan dari Sampel Output Asinkron.

  2. Buat proyek Aplikasi Formulir Windows di Microsoft Visual Studio 2013.

  3. Bagian kode di bawah ini mencakup dua file, AsyncApp.cs dan AsyncApp.Designer.cs.

  4. Dalam proyek yang baru dibuat, ganti Form1.cs dengan AsyncApp.cs dan Form1.Designer.cs dengan AsyncApp.Designer.cs.

  5. Jika belum ada, tambahkan referensi rakitan ke Microsoft.PointOfService.dll. Dalam penginstalan standar, Anda dapat menemukan file ini di bawah File Program (x86)\Microsoft Point Of Service\SDK.

  6. Kompilasi dan jalankan.

Untuk menjalankan sampel

  1. Sampel ini menampilkan antarmuka pengguna GUI yang memungkinkan pengguna mengirim permintaan cetak asinkron dan sinkron ke Objek Layanan Sampel Output Asinkron.

  2. Objek Layanan menunggu beberapa detik sebelum kembali dari permintaan, apakah itu sinkron atau asinkron.

  3. UI menampilkan status setiap permintaan dalam kotak teks.

Contoh

Kode sampel ini menunjukkan beberapa poin utama:

  • Menggunakan peristiwa OutputCompleteEvent untuk memberi tahu aplikasi bahwa Objek Layanan telah menyelesaikan permintaan output.
  • Mendaftarkan penanganan aktivitas, termasuk menggunakan refleksi untuk melakukannya.
  • Menggunakan PosExplorer untuk mencari Objek Layanan tertentu.

Untuk menunjukkan bagaimana pantulan dapat digunakan untuk menemukan peristiwa mana yang tersedia pada objek tertentu, kode ini menggunakan objek yang PosCommon dikembalikan tanpa CreateInstance(DeviceInfo) terlebih dahulu mentransmisikannya ke PosPrinter. Dalam kebanyakan kasus, aplikasi tidak perlu generik dengan cara itu dan begitu juga akan melemparkan objek sebagaimana mestinya.

// ASYNCAPP.CS
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Threading;
using System.Windows.Forms;
using System.Reflection;
using Microsoft.PointOfService;

namespace AsyncOutputApp
{
    public partial class AsyncApp : Form
    {
        PosCommon posCommon;
        PosExplorer posExplorer;

        public AsyncApp()
        {
            InitializeComponent();

            btnPrintAsync.Enabled = true;
            btnPrintSync.Enabled = true;

            posExplorer = new PosExplorer(this);
            posCommon = null;

            string SOName = "AsyncOutputPrinter";

            try
            {
                OpenDevice(SOName);
                SetupEvents();
            }
            catch
            {
                MessageBox.Show("The Service Object '" +
                        SOName + "' failed to load",
                        "Service Object Error",
                        MessageBoxButtons.OK,
                        MessageBoxIcon.Exclamation);

                btnPrintAsync.Enabled = false;
                btnPrintSync.Enabled = false;
            }
        }

        private void OpenDevice(string SOName)
        {
            string str = txtPrintResults.Text;
            DeviceInfo device = null;

            txtPrintResults.Clear();

            {
                // Retrieve the list of PosPrinter Service Objects.
                DeviceCollection devices =
                        posExplorer.GetDevices(
                        DeviceType.PosPrinter);

                // Iterate through the list looking for the one
                // needed for this sample.
                foreach(DeviceInfo d in devices)
                {
                    if(d.ServiceObjectName == SOName)
                    {
                        device = d;
                        break;
                    }
                }

                if (device == null)
                {
                    throw new Exception("Service Object not found");
                }

                txtPrintResults.Text = "Opening device: " +
                        device.ServiceObjectName + ", type: " +
                        device.Type + "\r\n";

                posCommon =
                        (PosCommon)posExplorer.CreateInstance(device);

                posCommon.Open();
                posCommon.Claim(0);
                posCommon.DeviceEnabled = true;
            }
        }

        // When this button is pressed, AsyncMode is turned off,
        // and the application waits for each print request
        // to complete before regaining control.
        private void btnPrintSync_Click(object sender, EventArgs e)
        {
            PosPrinter posPrinter = posCommon as PosPrinter;
            posPrinter.AsyncMode = false;

            txtPrintResults.AppendText(
                        "Printing will take place " +
                        "synchronously.\r\n");

            StartPrinting();
        }

        // When this button is pressed, AsyncMode is turned on. Print
        // requests will be queued and delivered on a
        // first-in-first-out basis.
        private void btnPrintAsync_Click(object sender, EventArgs e)
        {
            PosPrinter posPrinter = posCommon as PosPrinter;
            posPrinter.AsyncMode = true;

            txtPrintResults.AppendText(
                        "Printing will take place " +
                        "asynchronously.\r\n");

            StartPrinting();
        }

        private void StartPrinting()
        {
            PosPrinter posPrinter = posCommon as PosPrinter;

            txtPrintResults.AppendText(
                        "Calling PrintNormal to start " +
                        "printing...\r\n");

            // Notice that calling PrintNormal() here may not result
            // in a print request being sent immediately to the
            // printer. In asynchronous mode, the requested is
            // placed in a first-in-first-out queue managed by
            // POS for .NET.
            try
            {
                posPrinter.PrintNormal(
                            PrinterStation.Receipt,
                            "This is do-nothing print data");
            }
            catch (PosControlException e)
            {
                txtPrintResults.AppendText(
                            "PrintNormal threw a " +
                            "PosControlException! Description: " +
                            e.Message + "\r\n");

                return;
            }

            // When data is sent to an output device, POS for .NET
            // updates the OutputId property in the target object.
            // When an OutputCompleteEvent is sent to the app,
            // the OutputCompleteEventArgs will contain this id.
            Int32 id = posPrinter.OutputId;

            txtPrintResults.AppendText(
                        "PrintNormal has returned! OutputID = " +
                        id + "\r\n");
        }

        // Visual Studio-generated code.
        private void AsyncApp_Load(object sender, EventArgs e)
        {
        }

        #region Event Registration
        private void SetupEvents()
        {
            // All PosCommon objects support StatusUpdateEvent and
            // DirectIOEvent events, so simply register a handler
            // for those events.
            posCommon.StatusUpdateEvent +=
                        new StatusUpdateEventHandler(
                        co_OnStatusUpdateEvent);

            posCommon.DirectIOEvent +=
                        new DirectIOEventHandler(
                        co_OnDirectIOEvent);

            // In addition to the events common to all devices
            // (StatusUpdateEvent and DirectIOEvent), a device
            // type may also support DataEvent, ErrorEvent, or
            // OutputCompleteEvent events.
            //
            // In this example, the following code uses reflection
            // to determine which events are supported by this
            // object (posCommon).
            //
            // However, in the general case, an application will know
            // what type of device was returned when PosExplorer
            // CreateInstance() was called;therefore will not
            // need to use reflection, but can instead register
            // event handlers using the mechanism used for
            // StatusUpdateEvent and DirectIOEvent events above.
            EventInfo dataEvent =
                        posCommon.GetType().GetEvent(
                        "DataEvent");
            if (dataEvent != null)
            {
                dataEvent.AddEventHandler(posCommon,
                        new DataEventHandler(
                        co_OnDataEvent));

                txtPrintResults.AppendText("Registering Event: " +
                        "DataEvent\r\n");
            }

            EventInfo errorEvent =
                        posCommon.GetType().GetEvent(
                        "ErrorEvent");
            if (errorEvent != null)
            {
                errorEvent.AddEventHandler(posCommon,
                        new DeviceErrorEventHandler(
                        co_OnErrorEvent));

                txtPrintResults.AppendText("Registering Event: " +
                        "ErrorEvent\r\n");
            }

            EventInfo outputCompleteEvent =
                        posCommon.GetType().GetEvent(
                        "OutputCompleteEvent");
            if (outputCompleteEvent != null)
            {
                outputCompleteEvent.AddEventHandler(
                        posCommon, new OutputCompleteEventHandler(
                        co_OnOutputCompleteEvent));

                txtPrintResults.AppendText("Registering Event: " +
                        "OutputCompleteEvent\r\n");
            }
        }
        #endregion Event Registration

        #region Event Handlers
        private void co_OnDataEvent(
                        object obj,
                        DataEventArgs d)
        {
            txtPrintResults.AppendText(d.ToString() + "\r\n");
        }

        private void co_OnStatusUpdateEvent(
                        object source,
                        StatusUpdateEventArgs d)
        {
            txtPrintResults.AppendText(d.ToString() + "\r\n");
        }

        private void co_OnDirectIOEvent(
                        object source,
                        DirectIOEventArgs d)
        {
            txtPrintResults.AppendText(d.ToString() + "\r\n");
        }

        private void co_OnErrorEvent(
                        object source,
                        DeviceErrorEventArgs d)
        {
            string str = d.ToString();

            MessageBox.Show(d.ToString(),
                        "OnErrorEvent called",
                        MessageBoxButtons.OK,
                        MessageBoxIcon.Error);

            txtPrintResults.AppendText(d.ToString() + "\r\n");
        }

        private void co_OnOutputCompleteEvent(
                        object source,
                        OutputCompleteEventArgs d)
        {
            txtPrintResults.AppendText(d.ToString() + "\r\n");
        }
        #endregion Event Handlers
    }
}

// ASYNCAPP.DESIGNER.CS
namespace AsyncOutputApp
{
    partial class AsyncApp
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.txtPrintResults = new System.Windows.Forms.TextBox();
            this.btnPrintSync = new System.Windows.Forms.Button();
            this.btnPrintAsync = new System.Windows.Forms.Button();
            this.SuspendLayout();
            //
            // txtPrintResults
            //
            this.txtPrintResults.BackColor = System.Drawing.SystemColors.Window;
            this.txtPrintResults.Location = new System.Drawing.Point(12, 119);
            this.txtPrintResults.Multiline = true;
            this.txtPrintResults.Name = "txtPrintResults";
            this.txtPrintResults.ReadOnly = true;
            this.txtPrintResults.ScrollBars = System.Windows.Forms.ScrollBars.Vertical;
            this.txtPrintResults.Size = new System.Drawing.Size(650, 200);
            this.txtPrintResults.TabIndex = 3;
            //
            // btnPrintSync
            //
            this.btnPrintSync.Location = new System.Drawing.Point(12, 12);
            this.btnPrintSync.Name = "btnPrintSync";
            this.btnPrintSync.Size = new System.Drawing.Size(132, 39);
            this.btnPrintSync.TabIndex = 1;
            this.btnPrintSync.Text = "Print Synchronous";
            this.btnPrintSync.UseVisualStyleBackColor = true;
            this.btnPrintSync.Click += new System.EventHandler(this.btnPrintSync_Click);
            //
            // btnPrintAsync
            //
            this.btnPrintAsync.Location = new System.Drawing.Point(12, 57);
            this.btnPrintAsync.Name = "btnPrintAsync";
            this.btnPrintAsync.Size = new System.Drawing.Size(132, 39);
            this.btnPrintAsync.TabIndex = 2;
            this.btnPrintAsync.Text = "Print Asynchronously";
            this.btnPrintAsync.UseVisualStyleBackColor = true;
            this.btnPrintAsync.Click += new System.EventHandler(this.btnPrintAsync_Click);
            //
            // AsyncApp
            //
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(685, 331);
            this.Controls.Add(this.btnPrintAsync);
            this.Controls.Add(this.btnPrintSync);
            this.Controls.Add(this.txtPrintResults);
            this.Name = "AsyncApp";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.AsyncApp_Load);
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.TextBox txtPrintResults;
        private System.Windows.Forms.Button btnPrintSync;
        private System.Windows.Forms.Button btnPrintAsync;
    }
}

Program akan menampilkan teks berikut jika Anda terlebih dahulu menekan Tombol Cetak Sinkron lalu tombol Cetak Asinkron .

Perangkat pembuka: AsyncOutputPrinter, jenis: Peristiwa PosPrinterRegistering: ErrorEventRegistering Event: OutputCompleteEventPrinting akan berlangsung secara sinkron. Memanggil PrintNormal untuk mulai mencetak... PrintNormal telah kembali! OutputID = 0Printing akan berlangsung secara asinkron. Memanggil PrintNormal untuk mulai mencetak... PrintNormal telah kembali! OutputID = 1Microsoft.PointOfService.OutputCompleteEventArgs, TimeStamp: 11:35:39 AM, EventId: 1, OutputId: 1.

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