通过JavaScript用C++降低Cell.Calculate方法的计算时间
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可能的使用场景
通常，我们建议用户调用Workbook.calculateFormula()方法一次，然后获取各个单元格的计算值。但有时，用户并不希望计算整个工作簿，他们只想计算单个单元格。Aspose.Cells提供了CalculationOptions.recursive属性，您可以将其设置为false，以显著减少单元格的计算时间。当递归属性设置为true时，每次调用都会重新计算所有依赖的单元格；而当递归属性为false时，依赖单元格只会计算一次，后续调用不会再次计算。
减少Cell.calculate()方法的计算时间
以下示例代码演示了CalculationOptions.recursive属性的用法。请使用给定的示例Excel文件执行此代码，并检查控制台输出。您会发现，将递归属性设置为false可以显著减少计算时间。请同时阅读注释，以更好理解此属性。
<!DOCTYPE html>
<html>
<head>
<title>Aspose.Cells Calculate Formulas Example</title>
</head>
<body>
<h1>Calculate Formulas 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 } = 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 resultEl = document.getElementById('result');
if (!fileInput.files.length) {
resultEl.innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
return;
}
const file = fileInput.files[0];
const arrayBuffer = await file.arrayBuffer();
// Instantiating a Workbook object by loading the uploaded file
const workbook = new Workbook(new Uint8Array(arrayBuffer));
// Test calculation time after setting recursive true
workbook.calculateFormula(); // initiate calculation
// Test calculation time after setting recursive false (specify ignoreError as false)
workbook.calculateFormula(false);
// Save the modified 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 = 'output.calculated.xlsx';
downloadLink.style.display = 'block';
downloadLink.textContent = 'Download Calculated Excel File';
resultEl.innerHTML = '<p style="color: green;">Calculation completed successfully! Click the download link to get the modified file.</p>';
});
</script>
</html>
<!DOCTYPE html>
<html>
<head>
<title>Aspose.Cells Example</title>
<meta charset="utf-8" />
</head>
<body>
<h1>Calculation Time Recursive Test</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
<button id="runExample">Run Calculation Test (Recursive true/false)</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, CalculationOptions } = 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();
// Instantiating a Workbook object by loading the uploaded file
const workbook = new Workbook(new Uint8Array(arrayBuffer));
// Access first worksheet
const ws = workbook.worksheets.get(0);
const runs = [true, false];
let outputHtml = '';
for (let r = 0; r < runs.length; r++) {
const rec = runs[r];
// Set the calculation option, set recursive true or false as per parameter
const opts = new CalculationOptions();
opts.recursive = rec;
// Start stopwatch
const start = performance.now();
// Calculate cell A1 one million times
for (let i = 0; i < 1000000; i++) {
ws.cells.get("A1").calculate(opts);
}
// Stop the watch
const end = performance.now();
// Calculate elapsed time in seconds
const estimatedTime = (end - start) / 1000;
// Record the elapsed time
const message = `Recursive ${rec}: ${estimatedTime} seconds`;
console.log(message);
outputHtml += `<p>${message}</p>`;
}
resultDiv.innerHTML = `<div style="color: green;">${outputHtml}</div>`;
});
</script>
</html>
控制台输出
这是在我们的机器上使用给定示例Excel文件执行上述示例代码的控制台输出。请注意，您的输出可能不同，但将递归属性设置为false后，耗时总是少于设置为true。
Recursive True: 96 seconds
Recursive False: 42 seconds