using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;

namespace QtyCheck
{
	// This class defines the UI for the COM+ Transaction 

	public class QtyForm : System.Windows.Forms.Form
	{
		private System.Windows.Forms.Label currentqtyLabel;
		private System.Windows.Forms.TextBox currentqty;
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.Label currqtylabel;
		private System.Windows.Forms.Button button1;
		private System.Windows.Forms.Button button2;
		private System.Windows.Forms.TextBox txtProduct;
		private System.Windows.Forms.TextBox txtnewQty;
		private System.Windows.Forms.Label label2;
		private System.Windows.Forms.Button button3;
		private System.Windows.Forms.Label label3;

		private System.ComponentModel.Container components = null;
		
		public QtyForm()
		{
			// Required for Windows Form Designer support
			//
			InitializeComponent();
		
		}

		protected override void OnLoad(EventArgs e)
		{					
			try
			{

The 'using' statement is used to Dispose the object in use on exiting the curly braces. Disposing COM+ objects are significant, as COM+ metadata such as context does not remain in memory unnecessarily; COM+ services such as Object Pooling also work properly.

			using( TransServer TransServer = new TransServer()) 
			{
currentqty.Text = TransServer.Getcurrentqty().ToString();
			}
			}
			catch(currentqtyNotReadException)
			{
MessageBox.Show("Unable to read the current qty”, "Error");
				Application.Exit();
			}
			catch(Exception ex)
			{
MessageBox.Show(ex.Message + "\nUnable to launch the COM+ Server.”, "Error");
				Application.Exit();
			}
		}

		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if(components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		private void InitializeComponent()
		{
			this.button1 = new System.Windows.Forms.Button();
			this.button2 = new System.Windows.Forms.Button();
			this.txtProduct = new System.Windows.Forms.TextBox();
			this.label1 = new System.Windows.Forms.Label();
			this.txtnewQty = new System.Windows.Forms.TextBox();
			this.label2 = new System.Windows.Forms.Label();
			this.button3 = new System.Windows.Forms.Button();
			this.label3 = new System.Windows.Forms.Label();
			this.currqtylabel = new System.Windows.Forms.Label();
			this.SuspendLayout();
			// 
			// button1
			// 
			this.button1.Location = new Point(8, 104);
			this.button1.Name = "button1";
			this.button1.Size = new System.Drawing.Size(88, 23);
			this.button1.TabIndex = 2;
			this.button1.Text = "&Update";
this.button1.Click += new System.EventHandler(this.Button1_Click);
			// 
			// button2
			// 
			this.button2.Location = new Point(104, 104);
			this.button2.Name = "button2";
			this.button2.Size = new System.Drawing.Size(88, 23);
			this.button2.TabIndex = 3;
			this.button2.Text = "&AutoUpdate";
this.button2.Click += new System.EventHandler(this.Button2_Click);
			// 
			// txtProduct
			// 
			this.txtProduct.BackColor = Color.White;
			this.txtProduct.Location = new Point(144, 8);
			this.txtProduct.Name = "txtProduct";
			this.txtProduct.ReadOnly = true;
			this.txtProduct.TabIndex = 7;
			this.txtProduct.Text = "";
			// 
			// label1
			// 
			this.label1.Location = new Point(32, 8);
			this.label1.Name = "label1";
			this.label1.Size = new System.Drawing.Size(80, 16);
			this.label1.TabIndex = 6;
			this.label1.Text = "Product Id:";
			// 
			// txtnewQty
			// 
			this.txtnewQty.Location = new Point(144, 40);
			this.txtnewQty.Name = "txtnewQty";
			this.txtnewQty.TabIndex = 8;
			this.txtnewQty.Text = "";
			// 
			// label2
			// 
			this.label2.Location = new Point(32, 40);
			this.label2.Name = "label2";
			this.label2.Size = new System.Drawing.Size(80, 16);
			this.label2.TabIndex = 9;
			this.label2.Text = "New Quantity:";
			// 
			// button3
			// 
			this.button3.Location = new Point(200, 104);
			this.button3.Name = "button3";
			this.button3.Size = new System.Drawing.Size(64, 23);
			this.button3.TabIndex = 10;
			this.button3.Text = "&Close";
			// 
			// label3
			// 
			this.label3.Location = new Point(34, 72);
			this.label3.Name = "label3";
			this.label3.Size = new System.Drawing.Size(94, 16);
			this.label3.TabIndex = 12;
			this.label3.Text = "Current Quantity:";
			// 
			// currqtylabel
			// 
this.currqtylabel.BorderStyle = BorderStyle.FixedSingle;
			this.currqtylabel.Location = new Point(144, 72);
			this.currqtylabel.Name = "currqtylabel";
			this.currqtylabel.Size = new Size(96, 16);
			this.currqtylabel.TabIndex = 13;
			// 
			// QtyForm
			// 
			this.AutoScaleBaseSize = new Size(5, 13);
			this.ClientSize = new System.Drawing.Size(280, 133);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
																		  this.currqtylabel,
						  this.label3,
						  this.button3,
						  this.txtnewQty,
						  this.label2,
						  this.txtProduct,
						  this.label1,
						  this.button2,
						  this.button1});
			this.Name = "QtyForm";
			this.Text = "Quantity on Hand - Product";
this.Load += new System.EventHandler(this.QtyForm_Load);
			this.ResumeLayout(false);

		}
		#endregion

		// Manual update -  Update button
		private void Button1_Click(object sender, System.EventArgs e)
		{
			int val = 0;
			try
			{
				val = int.Parse(newValue.Text);
			}
			catch
			{
				MessageBox.Show("Enter a value to update!");
				return;
			}
			try
			{
			using( TransServer TransServer = new TransServer())
				{
					TransServer.Update(txtProduct.Text, val);
				}
			}
			catch(Exception ex)
			{
				MessageBox.Show(ex.Message);
				return;
			}
			try
			{
using( TransServer TransServer = new TransServer())
				{
currentqty.Text = TransServer.Getcurrentqty(txtProduct.text).ToString();
				}
			}
			catch(currentqtyNotReadException)
			{
				MessageBox.Show("Unable to read”,"Error");
				return;
			}
		}

		// automatic transaction update - autoupdate button
		private void Button2_Click(object sender, System.EventArgs e)
		{
			int val = 0;
			try
			{
				val = int.Parse(newValue.Text);
			}
			catch
			{
				MessageBox.Show("Enter a value!");
				return;
			}
			try
			{
using( TransServer TransServer = new TransServer())
				{
					TransServer.AutoUpdate(val);
				}
			}
			catch(Exception ex)
			{
				MessageBox.Show(ex.Message);
				return;
			}
			try
			{
using( TransServer TransServer = new TransServer())
				{
currentqty.Text = TransServer.Getcurrentqty(txtProduct.Text).ToString();
				}
			}
			catch(Exception ex)
			{
				MessageBox.Show(ex.Message”, "Error");
				return;
			}
		}

		private static void Main(String[] args)
		{
			Application.Run(new QtyForm());
		}

	}
}