public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    public static string CNumToCh(string x)
    {
        //數(shù)字轉(zhuǎn)換為中文后的數(shù)組 
        string[] num = new string[] { "零", "壹", "貳", "叁", "肆", "伍", "陸", "柒", "捌", "玖" };
        //為數(shù)字位數(shù)建立一個位數(shù)組 
        string[] digit = new string[] { "", "拾", "佰", "仟" };
        //為數(shù)字單位建立一個單位數(shù)組 
        string[] units = new string[] { "", ",萬,", ",億,", ",萬億," };
        string returnValue = ""; //返回值 
        int finger = 0; //字符位置指針 
        int m = x.Length % 4; //取模 
        int k = 0;
        if (m > 0)
            k=x.Length / 4 + 1;
        else
            k=x.Length / 4;
        //外層循環(huán),四位一組,每組最后加上單位: ",萬億,",",億,",",萬," 
        for (int i = k; i > 0; i--)
        {
            int L = 4;
            if (i == k && m != 0)
                L = m;
            //得到一組四位數(shù) 
            string four = x.Substring(finger, L);
            int l = four.Length;
            //內(nèi)層循環(huán)在該組中的每一位數(shù)上循環(huán)  
            for (int j = 0; j < l; j++)
            {
                //處理組中的每一位數(shù)加上所在的位 
                int n = Convert.ToInt32(four.Substring(j, 1));
                if (n == 0)
                {
                    if (j < l - 1&& Convert.ToInt32(four.Substring(j + 1, 1)) > 0 && !returnValue.EndsWith(num[n]))
                        returnValue += num[n];
                }
                else
                {
                    if (!(n == 1 && (returnValue.EndsWith(num[0]) | returnValue.Length == 0) && j == l - 2))
                        returnValue += num[n];
                    returnValue += digit[l - j - 1];
                }
            }
            finger += L;
            //每組最后加上一個單位:",萬,",",億," 等 
            if (i < k) //如果不是最高位的一組 
            {
                if (Convert.ToInt32(four) != 0)
                    //如果所有4位不全是0則加上單位",萬,",",億,"等 
                    returnValue += units[i - 1];
            }
            else
            {
                //處理最高位的一組,最后必須加上單位 
                returnValue += units[i - 1];
            }
        }
        return returnValue;
    } 

    private void button1_Click(object sender, EventArgs e)
    {
        if (txtStr.Text.Trim() == "")
        {
            return;
        }
        else
        {
            if (txtStr.Text.Trim().Length > 16)
            {
                MessageBox.Show("數(shù)字金額太大！", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
            else
            {
                if (txtStr.Text.Trim().Substring(0, 1) == "0")
                {
                    MessageBox.Show("請正確輸入金額！", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                }
                else
                {
                    richTextBox1.Text = CNumToCh(txtStr.Text.Trim());
                }
            }
        }
    }

    private void txtStr_KeyPress(object sender, KeyPressEventArgs e)
    {
        if((e.KeyChar!=8&&!char.IsDigit(e.KeyChar))&&e.KeyChar!=13)
        {
            MessageBox.Show("請輸入數(shù)字！", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            txtStr.Text = "";
            txtStr.Focus();
        }
    }
}

partial class Form1
{
    /// <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.label2 = new System.Windows.Forms.Label();
        this.label1 = new System.Windows.Forms.Label();
        this.button1 = new System.Windows.Forms.Button();
        this.richTextBox1 = new System.Windows.Forms.RichTextBox();
        this.txtStr = new System.Windows.Forms.TextBox();
        this.SuspendLayout();
        // 
        // label2
        // 
        this.label2.AutoSize = true;
        this.label2.Location = new System.Drawing.Point(17, 53);
        this.label2.Name = "label2";
        this.label2.Size = new System.Drawing.Size(65, 12);
        this.label2.TabIndex = 8;
        this.label2.Text = "轉(zhuǎn)換結(jié)果：";
        // 
        // label1
        // 
        this.label1.AutoSize = true;
        this.label1.Location = new System.Drawing.Point(17, 15);
        this.label1.Name = "label1";
        this.label1.Size = new System.Drawing.Size(65, 12);
        this.label1.TabIndex = 7;
        this.label1.Text = "輸入數(shù)字：";
        // 
        // button1
        // 
        this.button1.Location = new System.Drawing.Point(329, 11);
        this.button1.Name = "button1";
        this.button1.Size = new System.Drawing.Size(75, 23);
        this.button1.TabIndex = 5;
        this.button1.Text = "開始轉(zhuǎn)換";
        this.button1.UseVisualStyleBackColor = true;
        this.button1.Click += new System.EventHandler(this.button1_Click);
        // 
        // richTextBox1
        // 
        this.richTextBox1.Location = new System.Drawing.Point(79, 53);
        this.richTextBox1.Name = "richTextBox1";
        this.richTextBox1.Size = new System.Drawing.Size(325, 131);
        this.richTextBox1.TabIndex = 9;
        this.richTextBox1.Text = "";
        // 
        // txtStr
        // 
        this.txtStr.Location = new System.Drawing.Point(79, 12);
        this.txtStr.Name = "txtStr";
        this.txtStr.Size = new System.Drawing.Size(244, 21);
        this.txtStr.TabIndex = 6;
        this.txtStr.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.txtStr_KeyPress);
        // 
        // Form1
        // 
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(414, 196);
        this.Controls.Add(this.richTextBox1);
        this.Controls.Add(this.txtStr);
        this.Controls.Add(this.label2);
        this.Controls.Add(this.label1);
        this.Controls.Add(this.button1);
        this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
        this.MaximizeBox = false;
        this.MinimizeBox = false;
        this.Name = "Form1";
        this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
        this.Text = "數(shù)字大小寫轉(zhuǎn)換";
        this.ResumeLayout(false);
        this.PerformLayout();

    }

    #endregion

    private System.Windows.Forms.Label label2;
    private System.Windows.Forms.Label label1;
    private System.Windows.Forms.Button button1;
    private System.Windows.Forms.RichTextBox richTextBox1;
    private System.Windows.Forms.TextBox txtStr;
}