渲染图表

Aspose.Cells API支持将Excel图表转换成图片格式，无需额外工具或应用程序。为了支持渲染，Chart类提供了toImage(string)方法及多种重载以满足不同应用需求。

将图表渲染为图像

Chart.toImage(string) 方法具有多种重载，以支持简单和高级渲染。如果应用需求是在默认尺寸中渲染图表，建议使用如下 Chart.toImage(string) 方法：

const path = require("path");
const AsposeCells = require("aspose.cells.node");

// The path to the documents directory.
const dataDir = path.join(__dirname, "data");

// Instantiating a Workbook object
const workbook = new AsposeCells.Workbook();
// Adding a new worksheet to the Workbook
const sheetIndex = workbook.getWorksheets().add();
// Obtaining the reference of the newly added worksheet by passing its index to WorksheetCollection
const worksheet = workbook.getWorksheets().get(sheetIndex);

// Adding sample values to cells
worksheet.getCells().get("A1").putValue(50);
worksheet.getCells().get("A2").putValue(100);
worksheet.getCells().get("A3").putValue(150);
worksheet.getCells().get("B1").putValue(4);
worksheet.getCells().get("B2").putValue(20);
worksheet.getCells().get("B3").putValue(50);

// Adding a chart to the worksheet
const chartIndex = worksheet.getCharts().add(AsposeCells.ChartType.Column, 5, 0, 15, 5);
// Accessing the instance of the newly added chart
const chart = worksheet.getCharts().get(chartIndex);
// Adding Series Collection (chart data source) to the chart ranging from "A1" cell to "B3"
chart.getNSeries().add("A1:B3", true);

// Converting chart to image
chart.toImage(path.join(dataDir, "chartEMF_out.emf"), AsposeCells.ImageType.Emf);

// Converting chart to Bitmap
chart.toImage(path.join(dataDir, "chartBMP_out.bmp"), AsposeCells.ImageType.Bmp);

也可以使用高级设置将图表渲染为图片。Aspose.Cells API提供了Chart.toImage(string)方法的重载版本，接受ImageOrPrintOptions实例，同时允许设置分辨率、平滑模式、图片格式等参数。

const path = require("path");
const AsposeCells = require("aspose.cells.node");

// The path to the documents directory.
const dataDir = path.join(__dirname, "data");
const filePath = path.join(dataDir, "sample.xlsx");
// Instantiating a Workbook object
const workbook = new AsposeCells.Workbook();
// Adding a new worksheet to the Workbook
const sheetIndex = workbook.getWorksheets().add();
// Obtaining the reference of the newly added worksheet by passing its index to WorksheetCollection
const worksheet = workbook.getWorksheets().get(sheetIndex);

// Adding sample values to cells
worksheet.getCells().get("A1").putValue(50);
worksheet.getCells().get("A2").putValue(100);
worksheet.getCells().get("A3").putValue(150);
worksheet.getCells().get("B1").putValue(4);
worksheet.getCells().get("B2").putValue(20);
worksheet.getCells().get("B3").putValue(50);

// Adding a chart to the worksheet
const chartIndex = worksheet.getCharts().add(AsposeCells.ChartType.Column, 5, 0, 15, 5);
// Accessing the instance of the newly added chart
const chart = worksheet.getCharts().get(chartIndex);
// Adding Series Collection (chart data source) to the chart ranging from "A1" cell to "B3"
chart.getNSeries().add("A1:B3", true);

// Create an instance of ImageOrPrintOptions and set a few properties
const options = new AsposeCells.ImageOrPrintOptions();
options.setVerticalResolution(300);
options.setHorizontalResolution(300);

// Convert chart to image with additional settings
chart.toImage(path.join(dataDir, "chartPNG_out.png"), options);

支持的图表类型的渲染

目前有一些不支持渲染的图表类型。这些图表类型在下表的Supported列中包含N。

图表类型	图表子类型	支持
Column	Column	Y
	ColumnStacked	Y
	Column100PercentStacked	Y
	Column3DClustered	Y
	Column3DStacked	Y
	Column3D100PercentStacked	Y
	Column3D	Y
Bar	Bar	Y
	BarStacked	Y
	Bar100PercentStacked	Y
	Bar3DClustered	Y
	Bar3DStacked	Y
	Bar3D100PercentStacked	Y
Line	Line	Y
	LineStacked	Y
	Line100PercentStacked	Y
	LineWithDataMarkers	Y
	LineStackedWithDataMarkers	Y
	Line100PercentStackedWithDataMarkers	Y
	Line3D	Y
Pie	Pie	Y
	Pie3D	Y
	PiePie	Y
	PieExploded	Y
	Pie3DExploded	Y
	PieBar	Y
Scatter	Scatter	Y
	ScatterConnectedByCurvesWithDataMarker	Y
	ScatterConnectedByCurvesWithoutDataMarker	Y
	ScatterConnectedByLinesWithDataMarker	Y
	ScatterConnectedByLinesWithoutDataMarker	Y
Area	Area	Y
	AreaStacked	Y
	Area100PercentStacked	Y
	Area3D	Y
	Area3DStacked	Y
	Area3D100PercentStacked	Y
Doughnut	Doughnut	Y
	DoughnutExploded	Y
Radar	Radar	Y
	RadarWithDataMarkers	Y
	RadarFilled	Y
Surface	Surface3D	N
	SurfaceWireframe3D	N
	SurfaceContour	N
	SurfaceContourWireframe	N
Bubble	Bubble	Y
	Bubble3D	N
Stock	StockHighLowClose	Y
	StockOpenHighLowClose	Y
	StockVolumeHighLowClose	Y
	StockVolumeOpenHighLowClose	Y
Cylinder	Cylinder	Y
	CylinderStacked	Y
	Cylinder100PercentStacked	Y
	CylindricalBar	Y
	CylindricalBarStacked	Y
	CylindricalBar100PercentStacked	Y
	CylindricalColumn3D	Y
Cone	Cone	Y
	ConeStacked	Y
	Cone100PercentStacked	Y
	ConicalBar	Y
	ConicalBarStacked	Y
	ConicalBar100PercentStacked	Y
	ConicalColumn3D	Y
Pyramid	Pyramid	Y
	PyramidStacked	Y
	Pyramid100PercentStacked	Y
	PyramidBar	Y
	PyramidBarStacked	Y
	PyramidBar100PercentStacked	Y
	PyramidColumn3D	Y
BoxWhisker	BoxWhisker	Y
Funnel	Funnel	Y
ParetoLine	ParetoLine	Y
Sunburst	Sunburst	Y
Treemap	Treemap	Y
Waterfall	Waterfall	Y
Histogram	Histogram	Y
Map	Map	N

如果尝试将不受支持的图表类型渲染为图像或PDF，则可能会得到大小为0的图像或空白PDF。

高级主题

• 将图表转换为PDF