金額格式化表單

by ph822720355

HTML

<div class="container">
        <h1>💰 訂單表單範例</h1>
        <p class="subtitle">輸入金額時會自動格式化（觸發 onchange 事件）</p>
        
        <form id="orderForm">
            <div class="form-group">
                <label for="customerName">客戶姓名 *</label>
                <input 
                    type="text" 
                    id="customerName" 
                    name="customerName"
                    placeholder="請輸入姓名"
                    required
                >
            </div>
            
            <div class="form-group">
                <label for="email">電子郵件</label>
                <input 
                    type="email" 
                    id="email" 
                    name="email"
                    placeholder="[email protected]"
                >
            </div>
            
            <div class="form-group">
                <label for="orderAmount">訂單金額 *</label>
                <input 
                    type="text" 
                    id="orderAmount" 
                    name="orderAmount"
                    placeholder="輸入後自動格式化"
                    onchange="doAmtFormat(this, 15)"
                    required
                >
                <div class="hint">💡 可輸入負數、包含文字，系統會自動過濾並格式化</div>
            </div>
            
            <div class="form-group">
                <label for="depositAmount">訂金金額</label>
                <input 
                    type="text" 
                    id="depositAmount" 
                    name="depositAmount"
                    placeholder="輸入後自動格式化"
                    onchange="doAmtFormat(this, 15)"
                >
                <div class="hint">💡 試試輸入: -abc12345xyz 或 00001234</div>
            </div>
            
            <div class="form-group">
                <label for="paymentMethod">付款方式</label>
                <select id="paymentMethod" name="paymentMethod">
                    <option value="">請選擇</option>
          ...

CSS

* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
        }
        
        .container {
            background: white;
            border-radius: 20px;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
            padding: 40px;
            max-width: 600px;
            width: 100%;
        }
        
        h1 {
            color: #333;
            margin-bottom: 10px;
            font-size: 28px;
        }
        
        .subtitle {
            color: #666;
            margin-bottom: 30px;
            font-size: 14px;
        }
        
        .form-group {
            margin-bottom: 25px;
        }
        
        label {
            display: block;
            margin-bottom: 8px;
            color: #555;
            font-weight: 600;
            font-size: 14px;
        }
        
        input[type="text"],
        input[type="number"],
        input[type="email"],
        select {
            width: 100%;
            padding: 12px 16px;
            border: 2px solid #e0e0e0;
            border-radius: 8px;
            font-size: 16px;
            transition: all 0.3s;
        }
        
        input[type="text"]:focus,
        input[type="number"]:focus,
        input[type="email"]:focus,
        select:focus {
            outline: none;
            border-color: #667eea;
            box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
        }
        
        .hint {
            font-size: 12px;
            color: #999;
            margin-top: 5px;
        }
        
        .button-group {
           ...

JavaScript

/**
         * 格式化金額輸入
         * @param {HTMLInputElement} field - 輸入框元素
         * @param {number} maxLen - 最大長度限制
         * @returns {boolean}
         */
        function doAmtFormat(field, maxLen) {
            let value = field.value.trim();
            
            // 處理負號
            const isNegative = value.startsWith('-');
            if (isNegative) {
                value = value.slice(1);
            }
            
            // 移除所有非數字字元
            let numericValue = value.replace(/\D/g, '');
            
            // 套用長度限制
            if (numericValue.length > maxLen) {
                numericValue = numericValue.slice(0, maxLen);
            }
            
            // 移除前導零，但保留至少一個 "0"
            numericValue = numericValue.replace(/^0+/, '') || '0';
            
            // 套用千分位格式
            const formatted = moneyFormat(numericValue);
            
            // 加回負號（如果有）
            field.value = isNegative ? `-${formatted}` : formatted;
            
            // 更新預覽
            updatePreview();
            
            return true;
        }

        /**
         * 加上千分位逗號
         * @param {string} str - 數字字串
         * @returns {string} 格式化後的字串
         */
        function moneyFormat(str) {
            return str.replace(/\B(?=(\d{3})+(?!\d))/g, ',');
        }

        /**
         * 更新表單預覽
         */
        function updatePreview() {
            const form = document.getElementById('orderForm');
            const preview = document.getElementById('preview');
            
            // 取得表單值
            const name = form.customerName.value;
            const email = form.email.value;
            const amount = form.orderAmount.value;
            const deposit = form.depositAmount.value;
            const payment = form.paymentMethod.options[form.paymentMethod.selectedIndex].text;
            
            // 更新預覽
           ...