c# - - - 创建一个基于 WinForm 的英文字母大小写转换工具

界面

代码

using System;
using System.Windows.Forms;

namespace CaseConverterTool
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            InitializeUI();
        }

        private void InitializeUI()
        {
            // 设置窗口标题和大小
            this.Text = "英文字母大小写转换工具";
            this.Size = new System.Drawing.Size(600, 400);
            this.StartPosition = FormStartPosition.CenterScreen;

            // 创建输入标签
            Label inputLabel = new Label();
            inputLabel.Text = "请输入需要转换的文本:";
            inputLabel.Location = new System.Drawing.Point(20, 20);
            inputLabel.AutoSize = true;
            this.Controls.Add(inputLabel);

            // 创建输入文本框
            TextBox inputTextBox = new TextBox();
            inputTextBox.Multiline = true;
            inputTextBox.ScrollBars = ScrollBars.Vertical;
            inputTextBox.Location = new System.Drawing.Point(20, 45);
            inputTextBox.Size = new System.Drawing.Size(540, 100);
            inputTextBox.Name = "inputTextBox";
            this.Controls.Add(inputTextBox);

            // 创建按钮面板
            Panel buttonPanel = new Panel();
            buttonPanel.Location = new System.Drawing.Point(20, 160);
            buttonPanel.Size = new System.Drawing.Size(540, 40);
            buttonPanel.Name = "buttonPanel";
            this.Controls.Add(buttonPanel);

            // 创建转大写按钮
            Button toUpperButton = new Button();
            toUpperButton.Text = "转大写";
            toUpperButton.Location = new System.Drawing.Point(10, 5);
            toUpperButton.Size = new System.Drawing.Size(120, 30);
            toUpperButton.Name = "toUpperButton";
            toUpperButton.Click += (sender, e) => 
            {
                if (this.Controls["inputTextBox"] is TextBox input && 
                    this.Controls["outputTextBox"] is TextBox output)
                {
                    output.Text = input.Text.ToUpper();
                }
            };
            buttonPanel.Controls.Add(toUpperButton);

            // 创建转小写按钮
            Button toLowerButton = new Button();
            toLowerButton.Text = "转小写";
            toLowerButton.Location = new System.Drawing.Point(150, 5);
            toLowerButton.Size = new System.Drawing.Size(120, 30);
            toLowerButton.Name = "toLowerButton";
            toLowerButton.Click += (sender, e) => 
            {
                if (this.Controls["inputTextBox"] is TextBox input && 
                    this.Controls["outputTextBox"] is TextBox output)
                {
                    output.Text = input.Text.ToLower();
                }
            };
            buttonPanel.Controls.Add(toLowerButton);

            // 创建大小写互换按钮
            Button swapCaseButton = new Button();
            swapCaseButton.Text = "大小写互换";
            swapCaseButton.Location = new System.Drawing.Point(290, 5);
            swapCaseButton.Size = new System.Drawing.Size(120, 30);
            swapCaseButton.Name = "swapCaseButton";
            swapCaseButton.Click += (sender, e) => 
            {
                if (this.Controls["inputTextBox"] is TextBox input && 
                    this.Controls["outputTextBox"] is TextBox output)
                {
                    output.Text = SwapCase(input.Text);
                }
            };
            buttonPanel.Controls.Add(swapCaseButton);

            // 创建复制结果按钮
            Button copyButton = new Button();
            copyButton.Text = "复制结果";
            copyButton.Location = new System.Drawing.Point(430, 5);
            copyButton.Size = new System.Drawing.Size(100, 30);
            copyButton.Name = "copyButton";
            copyButton.Click += (sender, e) => 
            {
                if (this.Controls["outputTextBox"] is TextBox output && !string.IsNullOrEmpty(output.Text))
                {
                    Clipboard.SetText(output.Text);
                    MessageBox.Show("已复制到剪贴板！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
            };
            buttonPanel.Controls.Add(copyButton);

            // 创建输出标签
            Label outputLabel = new Label();
            outputLabel.Text = "转换结果:";
            outputLabel.Location = new System.Drawing.Point(20, 210);
            outputLabel.AutoSize = true;
            this.Controls.Add(outputLabel);

            // 创建输出文本框
            TextBox outputTextBox = new TextBox();
            outputTextBox.Multiline = true;
            outputTextBox.ScrollBars = ScrollBars.Vertical;
            outputTextBox.Location = new System.Drawing.Point(20, 235);
            outputTextBox.Size = new System.Drawing.Size(540, 100);
            outputTextBox.Name = "outputTextBox";
            outputTextBox.ReadOnly = true;
            this.Controls.Add(outputTextBox);
        }

        /// <summary>
        /// 实现大小写互换功能
        /// </summary>
        private string SwapCase(string input)
        {
            char[] chars = input.ToCharArray();
            for (int i = 0; i < chars.Length; i++)
            {
                if (char.IsUpper(chars[i]))
                {
                    chars[i] = char.ToLower(chars[i]);
                }
                else if (char.IsLower(chars[i]))
                {
                    chars[i] = char.ToUpper(chars[i]);
                }
                // 非字母字符不做处理
            }
            return new string(chars);
        }
    }
}