Suivi de la progression de conversion d’Excel en TIFF avec JavaScript via C++
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Scénarios d’utilisation possibles
Parfois, la conversion de grands fichiers Excel peut prendre du temps. Pendant ce temps, vous pouvez souhaiter afficher la progression de la conversion du document au lieu d’un simple écran de chargement pour améliorer l’utilisabilité de votre application. Aspose.Cells for JavaScript via C++ supporte le suivi du processus de conversion du document en fournissant l’interface IPageSavingCallback. L’interface IPageSavingCallback fournit les méthodes pageStartSaving(PageStartSavingArgs) et pageEndSaving(PageEndSavingArgs) que vous pouvez implémenter dans votre classe personnalisée. Vous pouvez également contrôler quelles pages sont rendues, comme démontré dans la classe personnalisée TestPageSavingCallback.
Suivre la progression de la conversion d’Excel en TIFF
Le code ci-dessous charge le fichier Excel source et affiche la progression de sa conversion dans la console en utilisant la classe personnalisée TestPageSavingCallback qui implémente l’interface IPageSavingCallback. Le fichier de sortie généré est joint pour votre référence.
Code d’exemple
<!DOCTYPE html>
<html>
<head>
<title>Aspose.Cells Example</title>
</head>
<body>
<h1>Convert Workbook to TIFF</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
<button id="convertTiff">Convert to TIFF</button>
<a id="downloadLink" style="display: none;"></a>
<div id="result"></div>
</body>
<script src="aspose.cells.js.min.js"></script>
<script type="text/javascript">
const { Workbook, ImageOrPrintOptions, WorkbookRender, ImageType, 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('convertTiff').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 from the uploaded file
const workbook = new Workbook(new Uint8Array(arrayBuffer));
// Create ImageOrPrintOptions and configure for TIFF conversion
const opts = new ImageOrPrintOptions();
// Define TestTiffPageSavingCallback
class TestTiffPageSavingCallback {
// Implement pageSaving as a no-op handler; Aspose.Cells may call this during TIFF generation
pageSaving(args) {
// No-op: default behavior will be used for page saving
// If needed, args (like args.imageStream) can be modified here
}
}
// Assign callback and image type using property assignment (converted from setters)
opts.pageSavingCallback = new TestTiffPageSavingCallback();
opts.imageType = ImageType.Tiff;
// Create WorkbookRender and generate the TIFF image
const wr = new WorkbookRender(workbook, opts);
const outputData = wr.toImage();
// Create a Blob and provide a download link for the generated TIFF
const blob = new Blob([outputData], { type: 'image/tiff' });
const downloadLink = document.getElementById('downloadLink');
downloadLink.href = URL.createObjectURL(blob);
downloadLink.download = 'DocumentConversionProgressForTiff_out.tiff';
downloadLink.style.display = 'block';
downloadLink.textContent = 'Download TIFF File';
resultDiv.innerHTML = '<p style="color: green;">Conversion completed. Click the download link to save the TIFF.</p>';
});
});
</script>
</html>
Voici le code de la classe personnalisée TestTiffPageSavingCallback.
<!DOCTYPE html>
<html>
<head>
<title>Aspose.Cells Example - TIFF Page Saving Callback</title>
</head>
<body>
<h1>TIFF Page Saving Callback Example</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
<button id="runExample">Save as TIFF with Page Callback</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");
});
class TestTiffPageSavingCallback {
pageStartSaving(args) {
console.log(`Start saving page index ${args.pageIndex} of pages ${args.pageCount}`);
// Don't output pages before page index 2.
if (args.pageIndex < 2) {
args.isToOutput = false;
}
}
pageEndSaving(args) {
console.log(`End saving page index ${args.pageIndex} of pages ${args.pageCount}`);
// Don't output pages after page index 8.
if (args.pageIndex >= 8) {
args.hasMorePages = false;
}
}
}
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();
// Instantiating a Workbook object from the uploaded file
const workbook = new Workbook(new Uint8Array(arrayBuffer));
// Create TIFF save options and assign the page saving callback
const tiffOptions = new AsposeCells.TiffSaveOptions();
tiffOptions.pageSavingCallback = new TestTiffPageSavingCallback();
// Save the workbook as TIFF using the save options
const outputData = workbook.save(SaveFormat.Tiff, tiffOptions);
const blob = new Blob([outputData]);
const downloadLink = document.getElementById('downloadLink');
downloadLink.href = URL.createObjectURL(blob);
downloadLink.download = 'output.tiff';
downloadLink.style.display = 'block';
downloadLink.textContent = 'Download TIFF File';
document.getElementById('result').innerHTML = '<p style="color: green;">TIFF saved successfully! Click the download link to get the file.</p>';
});
</script>
</html>
Sortie console
Start saving page index 0 of pages 10</br>
End saving page index 0 of pages 10</br>
Start saving page index 1 of pages 10</br>
End saving page index 1 of pages 10</br>
Start saving page index 2 of pages 10</br>
End saving page index 2 of pages 10</br>
Start saving page index 3 of pages 10</br>
End saving page index 3 of pages 10</br>
Start saving page index 4 of pages 10</br>
End saving page index 4 of pages 10</br>
Start saving page index 5 of pages 10</br>
End saving page index 5 of pages 10</br>
Start saving page index 6 of pages 10</br>
End saving page index 6 of pages 10</br>
Start saving page index 7 of pages 10</br>
End saving page index 7 of pages 10</br>
Start saving page index 8 of pages 10</br>
End saving page index 8 of pages 10</br>