C# для профессионалов. Том II

 /// </summary>
 private void InitializeComponent {
 this.txtNumber = new System.Windows.Forms.TextBox;
 this.txtSign = new System.Windows.Forms.TextBox;
 this.cmdShowResults = new System.Windows.Forms.Button;
 this.label3 = new System.Windows.Forms.Label;
 this.label4 = new System.Windows.Forms.Label;
 this.label1 = new System.Windows.Forms.Label;
 this.label2 = new System.Windows.Forms.Label;
 this.txtResult = new System.Windows.Forms.TextBox;
 this.SuspendLayout;
 //
 // txtNumber
 //
 this.txtNumber.Location = new System.Drawing.Point(160, 24);
 this.txtNumber.Name = "txtNumber";
 this.txtNumber.TabIndex = 0;
 this.txtNumber.Text = "";
 //
 // txtSign
 //
 this.txtSign.Enabled = false;
 this.txtSign.Location = new System.Drawing.Point(160, 136);
 this.txtSign.Name = "txtSign";
 this.tхtSign.TabIndех = 1;
 this.txtSign.Text = "";
 //
 // cmdShowResults
 //
 this.cmdShowResults.Location = new System.Drawing.Point(24, 96);
 this.cmdShowResults.Name = "cmdShowResults";
 this.cmdShowResults.Size = new System.Drawing.Size(88, 23);
 this.cmdShowResults.TabIndex = 3;
 this.cmdShowResults.Text = "Show Results";
 this.cmdShowResults.Click +=
 new System.EventHandler(this.OnClickShowResults);
 //
 // label3
 //
 this.label3.Location = new System.Drawing.Point(72, 24);
 this.label3.Name = "label3";
 this.label3.Size = new System.Drawing.Size(80, 23);
 this.label3.TabIndex = 6;
 this.label3.Text = "Input a number";
 //
 // label4
 //
 this.label4.Location = new System.Drawing.Point(80, 184);
 this.label4.Name = "label4";
 this.label4.Size = new System.Drawing.Size(80, 16);
 this.label4.TabIndex = 7;
 this.label4.Text = "Square root is";
 //
 // label1
 //
 this.label1.Location = new System.Drawing.Point(112, 136);
 this.label1.Name = "label1";
 this.label1.Size = new System.Drawing.Size(40, 23);
 this.label1.TabIndex = 4;
 this.label1.Text = "Sign is";
 //
 // label2
 //
 this.label2.Location = new System.Drawing.Point(48, 184);
 this.label2.Name = "label2";
 this.label2.Size = new System.Drawing.Size(8, 8);
 this.label2.TabIndex = 5;
 //
 // txtResult
 //
 this.txtResult.Enabled = false;
 this.txtResult.Location = new System.Drawing.Point(160, 184);
 this.txtResult.Name = "txtResult";
 this.txtResult.TabIndex = 2;
 this.txtResult.Text = "";
 //
 // Form1
 //
 this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
 this.ClientSize = new System.Drawing.Size(292, 269);
 this.Controls.AddRange(new System.Windows.Forms.Control[] {
 this.label4, this.label3, this.label2, this.label1,
 this.cmdShowResults, this.txtResult, this.txtSign, this.txtNumber
 });
 this.Name = "Form1";
 this.Text = "Square Root C# Sample";
 this.ResumeLayout(false);
 }
#endregion

 /// <summary>
/// Обработчик событий для нажатия пользователем кнопки Show Results
 /// Выводит квадратный корень и знак числа
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 private void OnClickShowResults(object sender, System.EventArgs e) {
 float NumberInput = float.Parse(this.txtNumber.Text);
 if (NumberInput < 0) {
 this.txtSign.Text = "Negative";
 this.txtResult.Text = Math.Sqrt(-NumberInput) + " i";
 } else if (NumberInput == 0) {
 txtSign.Text = "Zero";
 txtResult.Text = "0";
 } else {
 this.txtSign.Text = "Positive";
 this.txtResult.Text = Math.Sqrt(NumberInput).ToString;
 }
 }
 }

 class MainEntryClass {
 /// <summary>
 /// Основная точка входа приложения.