Cara Mengubah Respons API Menjadi Laporan Excel di C#

Dalam dunia berbasis data hari ini, perusahaan sangat bergantung pada REST APIs untuk pertukaran data. Namun, banyak pihak berkepentingan lebih suka mengkonsumsi data ini dalam format Excel untuk analisis dan laporan. Panduan ini menunjukkan bagaimana untuk membangun aplikasi C# lengkap yang:

Terhubung ke REST APIs
Mengalihkan data respon JSON
Mengkonversi data ke laporan Excel yang terformat secara profesional
Menambah visualisasi dengan grafis dan tabel

Nilai Bisnis

Penyelesaian ini memberikan nilai yang signifikan dengan:

Automating manual data extraction dan reporting creation process
Menjamin ketepatan data dengan menghapus salinan manual
Menyediakan format laporan yang konsisten
Memungkinkan generasi laporan yang direncanakan

Panduan Implementasi Langkah-Langkah

Langkah 1: Membuat aplikasi C# baru

Mulai dengan membuat aplikasi konsol baru:

dotnet new console -n ApiToExcelReporter
cd ApiToExcelReporter

Langkah 2: Menginstal paket yang diperlukan

Tambahkan paket NuGet yang diperlukan:

dotnet add package Aspose.Cells
dotnet add package Newtonsoft.Json
dotnet add package RestSharp

Langkah 3: Mengimplementasikan REST API Client

Mencipta layanan untuk komunikasi API:

using RestSharp;
using Newtonsoft.Json;
using System;
using System.Threading.Tasks;

public class ApiService
{
    private readonly RestClient _client;
    
    public ApiService(string baseUrl)
    {
        _client = new RestClient(baseUrl);
    }
    
    public async Task<T> GetApiDataAsync<T>(string endpoint, string apiKey = null)
    {
        var request = new RestRequest(endpoint, Method.Get);
        
        // Add authentication if needed
        if (!string.IsNullOrEmpty(apiKey))
        {
            request.AddHeader("Authorization", $"Bearer {apiKey}");
        }
        
        var response = await _client.ExecuteAsync(request);
        
        if (response.IsSuccessful)
        {
            return JsonConvert.DeserializeObject<T>(response.Content);
        }
        
        throw new Exception($"API call failed: {response.ErrorMessage}");
    }
}

Langkah 4: Proses JSON Response Data

Tambah kelas untuk memproses data JSON:

using Newtonsoft.Json.Linq;
using System.Collections.Generic;

public class DataProcessor
{
    public List<Dictionary<string, object>> FlattenJsonData(string jsonData)
    {
        var results = new List<Dictionary<string, object>>();
        JToken token = JToken.Parse(jsonData);
        
        // Handle different JSON structures
        if (token is JArray array)
        {
            foreach (var item in array)
            {
                results.Add(FlattenObject(item));
            }
        }
        else if (token is JObject obj)
        {
            // For nested data like {"data": [{...}, {...}]}
            var dataToken = obj["data"] as JArray;
            if (dataToken != null)
            {
                foreach (var item in dataToken)
                {
                    results.Add(FlattenObject(item));
                }
            }
            else
            {
                results.Add(FlattenObject(obj));
            }
        }
        
        return results;
    }
    
    private Dictionary<string, object> FlattenObject(JToken token)
    {
        var result = new Dictionary<string, object>();
        FillDictionary(result, token, "");
        return result;
    }
    
    private void FillDictionary(Dictionary<string, object> dict, JToken token, string prefix)
    {
        switch (token.Type)
        {
            case JTokenType.Object:
                foreach (var prop in token.Children<JProperty>())
                {
                    FillDictionary(dict, prop.Value, 
                        string.IsNullOrEmpty(prefix) ? prop.Name : $"{prefix}.{prop.Name}");
                }
                break;
                
            case JTokenType.Array:
                int index = 0;
                foreach (var item in token.Children())
                {
                    FillDictionary(dict, item, $"{prefix}[{index}]");
                    index++;
                }
                break;
                
            default:
                dict[prefix] = ((JValue)token).Value;
                break;
        }
    }
}

Langkah 5: Konversi ke Excel dengan Aspose.Cells

Mengimplementasikan Konversi Excel:

using Aspose.Cells;
using Aspose.Cells.Utility;
using System;
using System.Collections.Generic;
using System.IO;

public class ExcelReportGenerator
{
    public void GenerateReport(string jsonData, string outputPath)
    {
        // Create a new workbook
        Workbook workbook = new Workbook();
        Worksheet sheet = workbook.Worksheets[0];
        
        // Configure JSON layout options
        JsonLayoutOptions options = new JsonLayoutOptions
        {
            ArrayAsTable = true,
            ConvertNumericOrDate = true,
            IgnoreNull = true
        };
        
        // Make headers bold
        options.TitleStyle = new CellsFactory().CreateStyle();
        options.TitleStyle.Font.IsBold = true;
        
        // Import JSON data
        JsonUtility.ImportData(jsonData, sheet.Cells, 0, 0, options);
        
        // Auto-fit columns
        sheet.AutoFitColumns();
        
        // Save the workbook
        workbook.Save(outputPath);
    }
    
    public void GenerateReportFromObjects(List<Dictionary<string, object>> data, string outputPath)
    {
        Workbook workbook = new Workbook();
        Worksheet sheet = workbook.Worksheets[0];
        
        // Add headers if there's data
        if (data.Count > 0)
        {
            int col = 0;
            foreach (var key in data[0].Keys)
            {
                // Add header with styling
                Cell cell = sheet.Cells[0, col];
                cell.PutValue(key);
                
                Style style = cell.GetStyle();
                style.Font.IsBold = true;
                cell.SetStyle(style);
                
                col++;
            }
            
            // Add data rows
            for (int row = 0; row < data.Count; row++)
            {
                col = 0;
                foreach (var value in data[row].Values)
                {
                    sheet.Cells[row + 1, col].PutValue(value);
                    col++;
                }
            }
        }
        
        // Format as a table
        if (data.Count > 0)
        {
            int lastRow = data.Count;
            int lastCol = data[0].Count - 1;
            
            var tableRange = sheet.Cells.CreateRange(0, 0, lastRow + 1, lastCol + 1);
            sheet.ListObjects.Add(tableRange, "DataTable");
        }
        
        // Auto-fit columns
        sheet.AutoFitColumns();
        
        // Save the workbook
        workbook.Save(outputPath);
    }
}

Langkah 6: Tambahkan Formatting Profesional

Meningkatkan output Excel dengan styling profesional:

public void ApplyProfessionalFormatting(Workbook workbook)
{
    Worksheet sheet = workbook.Worksheets[0];
    
    // Create a style for the title
    Style titleStyle = workbook.CreateStyle();
    titleStyle.Font.Size = 14;
    titleStyle.Font.IsBold = true;
    titleStyle.HorizontalAlignment = TextAlignmentType.Center;
    
    // Add a title to the report
    sheet.Cells.Merge(0, 0, 1, sheet.Cells.MaxColumn + 1);
    Cell titleCell = sheet.Cells[0, 0];
    titleCell.PutValue("API Data Report - " + DateTime.Now.ToString("yyyy-MM-dd"));
    titleCell.SetStyle(titleStyle);
    
    // Insert a blank row after the title
    sheet.Cells.InsertRow(1);
    
    // Apply alternating row colors to the data
    Style evenRowStyle = workbook.CreateStyle();
    evenRowStyle.ForegroundColor = Color.FromArgb(240, 240, 240);
    evenRowStyle.Pattern = BackgroundType.Solid;
    
    int dataStartRow = 3; // Accounting for title and blank row
    int lastRow = sheet.Cells.MaxRow;
    
    for (int row = dataStartRow; row <= lastRow; row += 2)
    {
        for (int col = 0; col <= sheet.Cells.MaxColumn; col++)
        {
            sheet.Cells[row, col].SetStyle(evenRowStyle);
        }
    }
    
    // Add page header and footer
    sheet.PageSetup.SetHeader(1, "&\"Arial,Bold\"&14API Report");
    sheet.PageSetup.SetFooter(1, "Page &P of &N");
    
    // Set print options
    sheet.PageSetup.Orientation = PageOrientationType.Landscape;
    sheet.PageSetup.FitToPagesWide = 1;
    sheet.PageSetup.TopMargin = 0.5;
    sheet.PageSetup.LeftMargin = 0.5;
    sheet.PageSetup.RightMargin = 0.5;
    sheet.PageSetup.BottomMargin = 0.5;
}

Langkah 7: Menambahkan Data Visualisasi

Meningkatkan laporan dengan grafis:

public void AddChartVisualization(Workbook workbook, int dataColumn)
{
    Worksheet sheet = workbook.Worksheets[0];
    Worksheet chartSheet = workbook.Worksheets.Add("Chart Analysis");
    
    // Get the data range (skip header row)
    int lastRow = sheet.Cells.MaxRow;
    int nameColumn = 0; // Assuming first column has names/categories
    
    // Add a chart
    int chartIndex = chartSheet.Charts.Add(ChartType.Column, 2, 2, 20, 10);
    Chart chart = chartSheet.Charts[chartIndex];
    
    // Set the data range for the chart
    chart.NSeries.Add($"Sheet1!B2:B{lastRow + 1}", true);
    chart.NSeries.CategoryData = $"Sheet1!A2:A{lastRow + 1}";
    
    // Set chart title and other properties
    chart.Title.Text = "Data Analysis";
    chart.Legend.Position = LegendPositionType.Bottom;
    
    // Additional chart customization
    chart.NSeries[0].Area.ForegroundColor = Color.FromArgb(79, 129, 189);
    chart.PlotArea.Area.ForegroundColor = Color.White;
    
    // Add data labels
    chart.NSeries[0].DataLabels.IsValueShown = true;
    chart.NSeries[0].DataLabels.Position = DataLabelPositionType.OutsideEnd;
}

Langkah 8: Letakkan semuanya bersama

Buatlah program utama yang menghubungkan segala sesuatu:

using System;
using System.Threading.Tasks;

class Program
{
    static async Task Main(string[] args)
    {
        try
        {
            // Configure API endpoint
            string baseUrl = "https://api.example.com";
            string endpoint = "/data/endpoint";
            string apiKey = "your-api-key"; // If needed
            
            // Connect to API and get data
            Console.WriteLine("Connecting to API...");
            var apiService = new ApiService(baseUrl);
            var jsonData = await apiService.GetApiDataAsync<string>(endpoint, apiKey);
            
            Console.WriteLine("Data retrieved successfully");
            
            // Generate Excel report
            Console.WriteLine("Generating Excel report...");
            var reportGenerator = new ExcelReportGenerator();
            
            // Option 1: Direct JSON to Excel conversion
            string outputPath = "ApiReport_" + DateTime.Now.ToString("yyyyMMdd_HHmmss") + ".xlsx";
            reportGenerator.GenerateReport(jsonData, outputPath);
            
            // Option 2: Process JSON and create enhanced report
            // var processor = new DataProcessor();
            // var processedData = processor.FlattenJsonData(jsonData);
            // reportGenerator.GenerateReportFromObjects(processedData, outputPath);
            
            Console.WriteLine($"Report saved to {outputPath}");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error: {ex.Message}");
        }
    }
}

Mengendalikan Struktur Respon API yang Berbeda

REST APIs mengembalikan data dalam berbagai format. berikut cara menangani struktur umum:

1) Berbagai objek

[
  { "id": 1, "name": "Product A", "price": 29.99 },
  { "id": 2, "name": "Product B", "price": 49.99 }
]

Untuk struktur ini, gunakan:

JsonLayoutOptions options = new JsonLayoutOptions();
options.ArrayAsTable = true;
JsonUtility.ImportData(jsonData, sheet.Cells, 0, 0, options);

2.Nested Object dengan Data Array

{
  "status": "success",
  "data": [
    { "id": 1, "name": "Product A", "price": 29.99 },
    { "id": 2, "name": "Product B", "price": 49.99 }
  ]
}

Gunakan kelas DataProcessor untuk mengekstrak array “data”, atau:

// Parse with Newtonsoft.Json
JObject jsonObj = JObject.Parse(jsonData);
JArray dataArray = (JArray)jsonObj["data"];

// Convert to string and import
string dataArrayJson = dataArray.ToString();
JsonUtility.ImportData(dataArrayJson, sheet.Cells, 0, 0, options);

3. array dan objek yang terjebak

{
  "categories": [
    {
      "name": "Electronics",
      "products": [
        { "id": 1, "name": "Laptop", "price": 999.99 },
        { "id": 2, "name": "Phone", "price": 699.99 }
      ]
    },
    {
      "name": "Books",
      "products": [
        { "id": 3, "name": "Novel", "price": 14.99 }
      ]
    }
  ]
}

Untuk struktur yang kompleks, buat beberapa lembar kerja:

// Parse the JSON
JObject root = JObject.Parse(jsonData);
JArray categories = (JArray)root["categories"];

// Create a worksheet for each category
foreach (var category in categories)
{
    string categoryName = category["name"].ToString();
    Worksheet sheet = workbook.Worksheets.Add(categoryName);
    
    // Get and import the products array
    JArray products = (JArray)category["products"];
    JsonUtility.ImportData(products.ToString(), sheet.Cells, 0, 0, options);
}

Mengambilnya ke tahap berikutnya: Laporan yang dijadwalkan

Untuk mengautomatikkan generasi laporan, tambahkan kemampuan jadwal:

// Install Task Scheduler package
// dotnet add package TaskScheduler

using Microsoft.Win32.TaskScheduler;

public void ScheduleDailyReportGeneration(string appPath)
{
    using (TaskService ts = new TaskService())
    {
        // Create a new task
        TaskDefinition td = ts.NewTask();
        td.RegistrationInfo.Description = "Daily API Data Report Generation";
        
        // Create a trigger that will fire daily at 7am
        td.Triggers.Add(new DailyTrigger { StartBoundary = DateTime.Today.AddHours(7) });
        
        // Create an action that will run the application
        td.Actions.Add(new ExecAction(appPath));
        
        // Register the task in the root folder
        ts.RootFolder.RegisterTaskDefinition("DailyApiReport", td);
    }
}

Ciri-ciri yang perlu dipertimbangkan

Pengiriman email - secara otomatis mengirim laporan melalui email
Multi-API integrasi - Menggabungkan data dari beberapa API
Raporan berbasis template - Gunakan template Excel untuk branding konsisten
Penciptaan dashboard - Menghasilkan dashboard interaktif Excel
Pencarian dan laporan kesalahan - Masalah log dan laporan keberhasilan/kegagalan

Dengan mengikuti panduan ini, Anda telah membuat aplikasi C# yang kuat yang mengautomatikkan proses pengambilan data API dan menukarkannya ke laporan Excel profesional – menjimatkan waktu, memastikan ketepatan, dan memberikan nilai bisnis.