# C# {/* #c */}

首先阅读 [REST 指南](/docs/zh/api/rest)，创建平台 API 令牌。本示例使用 `HttpClient` 和内置 JSON API；无需生成 gRPC 客户端。

创建控制台项目：

```bash
dotnet new console -n ReconstructRestExample
```

进入项目目录：

```bash
cd ReconstructRestExample
```

使用以下 `Program.cs`：

```csharp
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text.Json;

var token = Environment.GetEnvironmentVariable("CR_RECONSTRUCT_API_TOKEN")
    ?? throw new InvalidOperationException("Set CR_RECONSTRUCT_API_TOKEN.");
var baseUrl = Environment.GetEnvironmentVariable("CR_RECONSTRUCT_REST_URL")
    ?? "https://reconstruct.dev/api/v1/platform";

using var client = new HttpClient { BaseAddress = new Uri(baseUrl.TrimEnd('/') + "/") };
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);

using var page = await client.GetFromJsonAsync<JsonDocument>("catalogs?pageSize=10")
    ?? throw new InvalidOperationException("The catalog response was empty.");

if (page.RootElement.TryGetProperty("catalogs", out var catalogs))
{
    foreach (var catalog in catalogs.EnumerateArray())
    {
        var id = catalog.GetProperty("catalogId").GetString()!;
        using var detail = await client.GetFromJsonAsync<JsonDocument>(
            "catalogs/" + Uri.EscapeDataString(id))
            ?? throw new InvalidOperationException("The catalog detail was empty.");
        Console.WriteLine($"{id}: {detail.RootElement.GetProperty("description").GetString()}");
    }
}
```

运行 `dotnet run`。如果列表响应中存在 `nextPageToken`，将其作为 URL 编码的 `pageToken` 查询参数发送，以继续获取后续内容。