Симон Робинсон - C# для профессионалов. Том II

Весь текст исходного кода достаточно длинный. Он представлен здесь для полноты, но лучше сразу перейти к последующим объяснениям и обращаться к исходному коду по мере необходимости.

using System;

using System.Drawing;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;

using System.Data;

namespace Wrox.ProfessionalCSharp.AppendixC.SquareRootSample {

///

/// Form, которая формирует основное окно приложения:

///

public class SquareRootForm : System.Windows.Forms.Form {

private System.Windows.Forms.TextBox txtNumber;

private System.Windows.Forms.TextBox txtSign;

private System.Windows.Forms.TextBox txtResult;

private System.Windows.Forms.Button cmdShowResults;

private System.Windows.Forms.Label label1;

private System.Windows.Forms.Label label2;

private System.Windows Forms.Label label3;

private System.Windows.Forms.Label label4;

///

/// Необходимые для designer переменные.

///

private System.ComponentModel.Container components;

public SquareRootForm() {

InitializeComponent();

}

public override void Dispose() {

base.Dispose();

if(components != null) components.Dispose();

}

#region Windows Form Designer generated code

///

/// Требуемый для поддержки Designer метод - не изменять

/// содержимое этого метода с помощью редактора кода.

///

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

///

/// Обработчик событий для нажатия пользователем кнопки Show Results

/// Выводит квадратный корень и знак числа

///

///

///

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 {

///

/// Основная точка входа приложения.

///

[STAThread]

static void Main() {

SquareRootForm TheMainForm = new SquareRootForm();

Application.Run(TheMainForm);

}

}

}