# 創(chuàng)建ASP.NET Core Web API項目
dotnet new webapi -n ChartToPdfDemo
cd ChartToPdfDemo
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# 安裝OxyPlot庫
dotnet add package OxyPlot.Core
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# 安裝OxyPlot的SVG導(dǎo)出支持（用于中間轉(zhuǎn)換）
dotnet add package OxyPlot.SkiaSharp
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# 安裝iText7庫
dotnet add package itext7

using iText.Kernel.Pdf;
using iText.Layout;
using iText.Layout.Element;
using iText.Layout.Properties;
using Microsoft.AspNetCore.Mvc;
using OxyPlot;
using OxyPlot.Axes;
using OxyPlot.Series;
using OxyPlot.SkiaSharp;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
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namespace ChartToPdfDemo.Controllers
{
    [ApiController]
    [Route("api/[controller]")]
    public class ChartController : ControllerBase
    {
        [HttpGet("export-to-pdf")]
        public async Task<IActionResult> ExportChartToPdf()
        {
            // 1. 創(chuàng)建圖表
            var plotModel = CreateBarChart();
            
            // 2. 將圖表轉(zhuǎn)換為圖像流
            byte[] imageBytes;
            using (var memoryStream = new MemoryStream())
            {
                var exporter = new PngExporter
                {
                    Width = 800,
                    Height = 600,
                    Resolution = 300
                };
                exporter.Export(plotModel, memoryStream);
                imageBytes = memoryStream.ToArray();
            }
            
            // 3. 創(chuàng)建PDF文檔并插入圖表
            using (var memoryStream = new MemoryStream())
            {
                PdfWriter writer = new PdfWriter(memoryStream);
                PdfDocument pdfDoc = new PdfDocument(writer);
                Document document = new Document(pdfDoc);
                
                // 添加標(biāo)題
                document.Add(new Paragraph("銷售數(shù)據(jù)分析報告")
                    .SetTextAlignment(TextAlignment.CENTER)
                    .SetFontSize(20)
                    .SetBold());
                
                // 添加圖表圖像
                using (var imageStream = new MemoryStream(imageBytes))
                {
                    iText.Layout.Element.Image pdfImage = new iText.Layout.Element.Image(
                        iText.IO.Image.ImageDataFactory.Create(imageStream.ToArray()));
                    
                    // 設(shè)置圖像適應(yīng)頁面寬度
                    pdfImage.SetAutoScale(true);
                    pdfImage.SetTextAlignment(TextAlignment.CENTER);
                    
                    document.Add(pdfImage);
                }
                
                // 添加圖表說明
                document.Add(new Paragraph("圖1: 各季度銷售額對比")
                    .SetTextAlignment(TextAlignment.CENTER)
                    .SetMarginTop(10)
                    .SetFontSize(12));
                
                // 添加數(shù)據(jù)分析
                document.Add(new Paragraph("數(shù)據(jù)分析:")
                    .SetBold()
                    .SetMarginTop(20)
                    .SetFontSize(14));
                
                document.Add(new Paragraph("從圖表中可以看出，第三季度的銷售額最高，達(dá)到了85萬元，比第二季度增長了約15%。這可能與我們在第三季度推出的促銷活動有關(guān)。第四季度銷售額略有下降，但仍保持在較高水平。建議在第一季度制定新的營銷策略，以提升開年銷售業(yè)績。")
                    .SetFontSize(12)
                    .SetFirstLineIndent(20)
                    .SetMultipliedLeading(1.5f));
                
                // 關(guān)閉文檔
                document.Close();
                
                // 4. 返回PDF文件
                return File(memoryStream.ToArray(), "application/pdf", "銷售報告.pdf");
            }
        }
        
        /// <summary>
        /// 創(chuàng)建柱狀圖
        /// </summary>
        /// <returns>圖表模型</returns>
        private PlotModel CreateBarChart()
        {
            // 創(chuàng)建圖表模型
            var model = new PlotModel {
                Title = "季度銷售額統(tǒng)計",
                TitleFontSize = 16,
                Padding = new OxyThickness(20)
            };
            
            // 創(chuàng)建坐標(biāo)軸
            var categoryAxis = new CategoryAxis {
                Position = AxisPosition.Bottom,
                Title = "季度",
                ItemsSource = new[] { "第一季度", "第二季度", "第三季度", "第四季度" }
            };
            
            var valueAxis = new LinearAxis {
                Position = AxisPosition.Left,
                Title = "銷售額（萬元）",
                Minimum = 0,
                Maximum = 100
            };
            
            model.Axes.Add(categoryAxis);
            model.Axes.Add(valueAxis);
            
            // 創(chuàng)建柱狀圖系列
            var series = new ColumnSeries {
                Title = "實際銷售額",
                FillColor = OxyColors.SkyBlue,
                StrokeColor = OxyColors.Black,
                StrokeThickness = 1,
                ItemsSource = new[] {
                    new ColumnItem(55),
                    new ColumnItem(74),
                    new ColumnItem(85),
                    new ColumnItem(79)
                }
            };
            
            model.Series.Add(series);
            
            return model;
        }
    }
}

[HttpGet("export-multiple-charts")]
public async Task<IActionResult> ExportMultipleChartsToPdf()
{
    using (var memoryStream = new MemoryStream())
    {
        PdfWriter writer = new PdfWriter(memoryStream);
        PdfDocument pdfDoc = new PdfDocument(writer);
        Document document = new Document(pdfDoc);
        
        // 添加報告標(biāo)題
        document.Add(new Paragraph("年度業(yè)務(wù)分析報告")
            .SetTextAlignment(TextAlignment.CENTER)
            .SetFontSize(22)
            .SetBold()
            .SetMarginBottom(30));
        
        // 添加銷售額圖表
        AddChartToDocument(document, CreateBarChart(), "圖1: 各季度銷售額對比");
        
        // 添加新頁面
        pdfDoc.AddNewPage();
        
        // 添加利潤率圖表（折線圖）
        AddChartToDocument(document, CreateLineChart(), "圖2: 各季度利潤率變化趨勢");
        
        // 添加新頁面
        pdfDoc.AddNewPage();
        
        // 添加產(chǎn)品占比圖表（餅圖）
        AddChartToDocument(document, CreatePieChart(), "圖3: 各產(chǎn)品銷售額占比");
        
        document.Close();
        
        return File(memoryStream.ToArray(), "application/pdf", "年度業(yè)務(wù)分析報告.pdf");
    }
}
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/// <summary>
/// 將圖表添加到PDF文檔
/// </summary>
private void AddChartToDocument(Document document, PlotModel plotModel, string caption)
{
    // 圖表轉(zhuǎn)換為圖像
    byte[] imageBytes;
    using (var memoryStream = new MemoryStream())
    {
        var exporter = new PngExporter
        {
            Width = 800,
            Height = 500,
            Resolution = 300
        };
        exporter.Export(plotModel, memoryStream);
        imageBytes = memoryStream.ToArray();
    }
    
    // 添加圖表到PDF
    using (var imageStream = new MemoryStream(imageBytes))
    {
        iText.Layout.Element.Image pdfImage = new iText.Layout.Element.Image(
            iText.IO.Image.ImageDataFactory.Create(imageStream.ToArray()));
        
        pdfImage.SetAutoScale(true);
        pdfImage.SetTextAlignment(TextAlignment.CENTER);
        
        document.Add(pdfImage);
    }
    
    // 添加圖表標(biāo)題
    document.Add(new Paragraph(caption)
        .SetTextAlignment(TextAlignment.CENTER)
        .SetMarginTop(10)
        .SetFontSize(12));
}
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/// <summary>
/// 創(chuàng)建折線圖
/// </summary>
private PlotModel CreateLineChart()
{
    var model = new PlotModel {
        Title = "季度利潤率趨勢",
        TitleFontSize = 16
    };
    
    model.Axes.Add(new CategoryAxis {
        Position = AxisPosition.Bottom,
        Title = "季度",
        ItemsSource = new[] { "第一季度", "第二季度", "第三季度", "第四季度" }
    });
    
    model.Axes.Add(new LinearAxis {
        Position = AxisPosition.Left,
        Title = "利潤率（%）",
        Minimum = 0,
        Maximum = 30
    });
    
    var series = new LineSeries {
        Title = "利潤率",
        Color = OxyColors.Green,
        MarkerType = MarkerType.Circle,
        MarkerSize = 6,
        MarkerStroke = OxyColors.Green,
        MarkerFill = OxyColors.White,
        StrokeThickness = 2,
        ItemsSource = new[] {
            new DataPoint(0, 18),
            new DataPoint(1, 21),
            new DataPoint(2, 24),
            new DataPoint(3, 22)
        }
    };
    
    model.Series.Add(series);
    
    return model;
}
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/// <summary>
/// 創(chuàng)建餅圖
/// </summary>
private PlotModel CreatePieChart()
{
    var model = new PlotModel {
        Title = "產(chǎn)品銷售額占比",
        TitleFontSize = 16
    };
    
    var series = new PieSeries {
        StrokeThickness = 2,
        InsideLabelPosition = 0.8,
        OutsideLabelFormat = "{1}: {2}",
        InsideLabelFormat = "{2}",
        AngleSpan = 360,
        StartAngle = 90
    };
    
    series.Slices.Add(new PieSlice("產(chǎn)品A", 45) { Fill = OxyColors.SkyBlue });
    series.Slices.Add(new PieSlice("產(chǎn)品B", 30) { Fill = OxyColors.Pink });
    series.Slices.Add(new PieSlice("產(chǎn)品C", 15) { Fill = OxyColors.LightGreen });
    series.Slices.Add(new PieSlice("其他產(chǎn)品", 10) { Fill = OxyColors.LightYellow });
    
    model.Series.Add(series);
    
    return model;
}