feat: 新增表格边框样式控制功能

支持10种边框样式：
- all: 全部边框（默认）
- none: 无边框
- no-outer: 无外边线
- no-horizontal: 无横线
- no-vertical: 无竖线
- no-inner: 无内部线
- no-inner-horizontal: 无内部横线
- no-inner-vertical: 无内部竖线
- outer-only: 仅外边框
- header-only: 仅表头分隔线

前端和API均已支持

app.js

@@ -673,6 +673,7 @@ function generateTable() {
         theme: document.getElementById('tableTheme').value,
         fontSize: parseInt(document.getElementById('tableFontSize').value) || 14,
         stripeRows: document.getElementById('stripeRows').checked,
+        borderStyle: document.getElementById('borderStyle').value,
         pixelRatio: 2
     };
 

index.html

@@ -151,6 +151,22 @@ C, 20, 30, 40</pre>
                             <label><input type="checkbox" id="stripeRows" checked onchange="updateTable()"> 斑马纹</label>
                         </div>
                     </div>
+
+                    <div class="config-group">
+                        <label>边框样式</label>
+                        <select id="borderStyle" onchange="updateTable()">
+                            <option value="all">全部边框</option>
+                            <option value="none">无边框</option>
+                            <option value="no-outer">无外边线</option>
+                            <option value="no-horizontal">无横线</option>
+                            <option value="no-vertical">无竖线</option>
+                            <option value="no-inner">无内部线</option>
+                            <option value="no-inner-horizontal">无内部横线</option>
+                            <option value="no-inner-vertical">无内部竖线</option>
+                            <option value="outer-only">仅外边框</option>
+                            <option value="header-only">仅表头分隔线</option>
+                        </select>
+                    </div>
                 </div>
 
                 <!-- 系列配置区 -->

server.js

@@ -655,7 +655,8 @@ function generateTableImage(params) {
         borderWidth = 1,
         stripeRows = true,
         pixelRatio = 2,
-        maxWidth = 1200
+        maxWidth = 1200,
+        borderStyle = 'all' // all, none, no-outer, no-horizontal, no-vertical, no-inner, no-inner-horizontal, no-inner-vertical, outer-only, header-only
     } = params;
 
     const tableData = parseTableData(data);
@@ -763,35 +764,50 @@ function generateTableImage(params) {
     ctx.strokeStyle = themeConfig.borderColor;
     ctx.lineWidth = borderWidth;
 
-    // 外边框（向内偏移半个线宽，确保边框完全在画布内）
-    const offset = borderWidth / 2;
-    ctx.strokeRect(offset, startY + offset, finalWidth - borderWidth, tableHeight - borderWidth);
+    // 边框样式控制
+    const drawOuter = !['none', 'no-outer', 'no-inner', 'no-inner-horizontal', 'no-inner-vertical', 'header-only'].includes(borderStyle);
+    const drawHorizontal = !['none', 'no-horizontal', 'no-inner', 'no-inner-horizontal', 'outer-only', 'header-only'].includes(borderStyle);
+    const drawVertical = !['none', 'no-vertical', 'no-inner', 'no-inner-vertical', 'outer-only'].includes(borderStyle);
+    const drawHeaderLine = !['none', 'no-horizontal', 'no-inner', 'no-inner-horizontal'].includes(borderStyle);
 
-    // 横线
-    ctx.beginPath();
-    ctx.moveTo(0, startY + headerHeight);
-    ctx.lineTo(finalWidth, startY + headerHeight);
-    ctx.stroke();
+    // 外边框
+    if (drawOuter) {
+        const offset = borderWidth / 2;
+        ctx.strokeRect(offset, startY + offset, finalWidth - borderWidth, tableHeight - borderWidth);
+    }
 
-    rows.forEach((_, rowIdx) => {
-        const y = startY + headerHeight + (rowIdx + 1) * rowHeight;
+    // 表头分隔线（横线）
+    if (drawHeaderLine) {
         ctx.beginPath();
-        ctx.moveTo(0, y);
-        ctx.lineTo(finalWidth, y);
+        ctx.moveTo(0, startY + headerHeight);
+        ctx.lineTo(finalWidth, startY + headerHeight);
         ctx.stroke();
-    });
+    }
+
+    // 数据行横线
+    if (drawHorizontal) {
+        rows.forEach((_, rowIdx) => {
+            const y = startY + headerHeight + (rowIdx + 1) * rowHeight;
+            ctx.beginPath();
+            ctx.moveTo(0, y);
+            ctx.lineTo(finalWidth, y);
+            ctx.stroke();
+        });
+    }
 
     // 竖线
-    x = 0;
-    colWidths.forEach((width, i) => {
-        if (i > 0) {
-            ctx.beginPath();
-            ctx.moveTo(x, startY);
-            ctx.lineTo(x, startY + tableHeight);
-            ctx.stroke();
-        }
-        x += width;
-    });
+    if (drawVertical) {
+        x = 0;
+        colWidths.forEach((width, i) => {
+            if (i > 0) {
+                ctx.beginPath();
+                ctx.moveTo(x, startY);
+                ctx.lineTo(x, startY + tableHeight);
+                ctx.stroke();
+            }
+            x += width;
+        });
+    }
 
     return canvas;
 }
@@ -833,7 +849,8 @@ app.get('/api/table', (req, res) => {
             borderWidth: parseInt(req.query.borderWidth) || 1,
             stripeRows: req.query.stripeRows !== 'false',
             pixelRatio: parseInt(req.query.pixelRatio) || 2,
-            maxWidth: parseInt(req.query.maxWidth) || 1200
+            maxWidth: parseInt(req.query.maxWidth) || 1200,
+            borderStyle: req.query.borderStyle || 'all'
         };
 
         if (!params.data) {
@@ -951,7 +968,8 @@ app.get('/api/docs', (req, res) => {
                     borderWidth: { type: 'number', default: 1, description: '边框宽度' },
                     stripeRows: { type: 'boolean', default: true, description: '是否斑马纹' },
                     pixelRatio: { type: 'number', default: 2, description: '像素倍率（清晰度）' },
-                    maxWidth: { type: 'number', default: 1200, description: '最大宽度(px)' }
+                    maxWidth: { type: 'number', default: 1200, description: '最大宽度(px)' },
+                    borderStyle: { type: 'string', default: 'all', options: ['all', 'none', 'no-outer', 'no-horizontal', 'no-vertical', 'no-inner', 'no-inner-horizontal', 'no-inner-vertical', 'outer-only', 'header-only'], description: '边框样式' }
                 },
                 returns: 'image/png',
                 example: {