Följ konverteringsframsteg för Excel till TIFF med JavaScript via C++
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Möjliga användningsscenario
Ibland kan det ta tid att konvertera stora Excel-filer. Under denna tid kanske du vill visa dokumentomvandlingsprocessen istället för en laddningsskärm för att förbättra användbarheten av din applikation. Aspose.Cells for JavaScript via C++ stöder att spåra dokumentomvandlingsprocessen genom att tillhandahålla gränssnittet IPageSavingCallback. Gränssnittet IPageSavingCallback tillhandahåller pageStartSaving(PageStartSavingArgs) och pageEndSaving(PageEndSavingArgs) metoder som du kan implementera i din anpassade klass. Du kan också kontrollera vilka sidor som renderas, som demonstreras i den anpassade klassen TestPageSavingCallback.
Spåra konverteringsframsteg för Excel till TIFF
Följande kod exempel laddar käll excelfilen och skriver ut dess konverteringsframsteg i konsolen med hjälp av den anpassade klassen TestPageSavingCallback som implementerar IPageSavingCallback-gränssnittet. Utdatafilen som genereras är bifogad för din referens.
Exempelkod
<!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>
Nedan är koden för den anpassade klassen 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>
Konsoloutput
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>