通过 C++ 获取带有 JavaScript 的页眉或页脚

在MS Excel中获取页眉和页脚

  1. 单击要查看或更改页眉或页脚的工作表。
  2. 在“视图”选项卡的“工作簿视图”组中，点击“页面布局”。 Excel会以页面布局视图显示工作表。
  3. 要查看或编辑页眉或页脚，请单击工作表页面顶部或底部的左侧、中间或右侧页眉或页脚文本框（在页眉下方或在页脚上方）。

通过 C++ 获取 Aspose.Cells for JavaScript 的页眉和页脚

使用 PageSetup.header(number) 和 PageSetup.footer(number) 方法，JavaScript 开发者可以轻松从文件中获取页眉或页脚。

  1. 构建一个工作簿以打开文件。
  2. 获取包含你要获取标题或页脚的工作表。
  3. 使用特定节ID获取标题或页脚。
<!DOCTYPE html>
<html>
    <head>
        <title>Aspose.Cells Example</title>
    </head>
    <body>
        <h1>Header/Footer Reader Example</h1>
        <input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
        <button id="runExample">Run Example</button>
        <a id="downloadLink" style="display: none;">Download Result</a>
        <div id="result"></div>
    </body>

    <script src="aspose.cells.js.min.js"></script>
    <script type="text/javascript">
        const { Workbook, SaveFormat, Worksheet, Cell, Utils } = AsposeCells;

        AsposeCells.onReady({
            license: "/lic/aspose.cells.enc",
            fontPath: "/fonts/",
            fontList: [
                "arial.ttf",
                "NotoSansSC-Regular.ttf"
            ]
        }).then(() => {
            console.log("Aspose.Cells initialized");
        });

        function escapeHtml(str) {
            if (str === null || str === undefined) return '';
            return String(str)
                .replace(/&/g, '&amp;')
                .replace(/</g, '&lt;')
                .replace(/>/g, '&gt;')
                .replace(/"/g, '&quot;')
                .replace(/'/g, '&#039;');
        }

        document.getElementById('runExample').addEventListener('click', async () => {
            const fileInput = document.getElementById('fileInput');
            if (!fileInput.files.length) {
                document.getElementById('result').innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
                return;
            }

            const file = fileInput.files[0];
            const arrayBuffer = await file.arrayBuffer();

            // Instantiate a new Workbook from the uploaded file
            const workbook = new Workbook(new Uint8Array(arrayBuffer));
            const sheet = workbook.worksheets.get(0);

            // Gets left section of header
            const headerLeft = sheet.pageSetup.header(0);
            // Gets center section of header
            const headerCenter = sheet.pageSetup.header(1);
            // Gets right section of header
            const headerRight = sheet.pageSetup.header(2);
            // Gets center section of footer
            const footerCenter = sheet.pageSetup.footer(1);

            const resultHtml = [
                `<p><strong>Left Header:</strong> ${escapeHtml(headerLeft)}</p>`,
                `<p><strong>Center Header:</strong> ${escapeHtml(headerCenter)}</p>`,
                `<p><strong>Right Header:</strong> ${escapeHtml(headerRight)}</p>`,
                `<p><strong>Center Footer:</strong> ${escapeHtml(footerCenter)}</p>`
            ].join('');

            document.getElementById('result').innerHTML = resultHtml;
        });
    </script>
</html>

解析页眉和页脚为命令列表

标题或页脚文本可以包含特殊命令，例如用于页码、当前日期或文本格式属性的占位符。

特殊命令由带有前导“&”的单个字母表示。

标题和页脚字符串采用 ABNF 语法构建。不使用查看器很难理解。

Aspose.Cells for JavaScript 通过 C++ 提供 PageSetup.commands(string) 方法来解析页眉和页脚，作为命令列表。

以下代码展示了如何将标题或页脚解析为命令列表并处理命令：

<!DOCTYPE html>
<html>
    <head>
        <title>Aspose.Cells Header/Footer Commands Example</title>
    </head>
    <body>
        <h1>Header/Footer Commands Example</h1>
        <input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
        <button id="runExample">Run Example</button>
        <a id="downloadLink" style="display: none;">Download Result</a>
        <div id="result"></div>
    </body>

    <script src="aspose.cells.js.min.js"></script>
    <script type="text/javascript">
        const { Workbook, SaveFormat, Worksheet, Cell, Utils } = AsposeCells;

        AsposeCells.onReady({
            license: "/lic/aspose.cells.enc",
            fontPath: "/fonts/",
            fontList: [
                "arial.ttf",
                "NotoSansSC-Regular.ttf"
            ]
        }).then(() => {
            console.log("Aspose.Cells initialized");
        });

        document.getElementById('runExample').addEventListener('click', async () => {
            const fileInput = document.getElementById('fileInput');
            const resultDiv = document.getElementById('result');
            if (!fileInput.files.length) {
                resultDiv.innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
                return;
            }

            const file = fileInput.files[0];
            const arrayBuffer = await file.arrayBuffer();

            // Instantiate a Workbook from the uploaded file
            const workbook = new Workbook(new Uint8Array(arrayBuffer));
            const sheet = workbook.worksheets.get(0);

            // Gets left section of header
            const headerSection = sheet.pageSetup.header(0);
            const commands = sheet.pageSetup.commands(headerSection) || [];

            const items = [];
            commands.forEach(c => {
                const type = c.type;
                switch (type) {
                    case AsposeCells.HeaderFooterCommandType.SheetName:
                        // embedded the name of the sheet to header or footer
                        items.push('<li>SheetName command found (embeds sheet name)</li>');
                        break;
                    default:
                        items.push(`<li>Command type: ${type}</li>`);
                        break;
                }
            });

            if (!items.length) {
                items.push('<li>No header/footer commands found.</li>');
            }

            resultDiv.innerHTML = `<ul>${items.join('')}</ul>`;

            // Save the (possibly unchanged) workbook and provide a download link
            const outputData = workbook.save(SaveFormat.Xlsx);
            const blob = new Blob([outputData]);
            const downloadLink = document.getElementById('downloadLink');
            downloadLink.href = URL.createObjectURL(blob);
            downloadLink.download = 'HeaderFooter_result.xlsx';
            downloadLink.style.display = 'block';
            downloadLink.textContent = 'Download Result Workbook';
        });
    </script>
</html>