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<p data-bm="38" style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: 8px 0px; padding: revert; -webkit-line-clamp: revert; color: rgba(0, 0, 0, 0.8); font-family: Roboto, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;" data-pasted="true">以下のように、<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">OnModelCreating</code> メソッド内で&nbsp;<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">wwwroot</code> フォルダ内の画像ファイルを読み取り、それらを&nbsp;<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">Model</code> クラスのフィールドに格納するコードを記述できます。以下はその実装例です。<h3 data-bm="39" style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert; display: inline-block; font: 20px / 22px Roboto, sans-serif; color: rgba(0, 0, 0, 0.8); letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">コード例</h3><pre data-priority="2" data-bm="40" style="background: none 0% 0% / auto repeat scroll padding-box border-box rgb(245, 245, 245); border-color: rgba(0, 0, 0, 0.1); border-style: solid; border-width: 1px; border-image: none 100% / 1 / 0 stretch; border-radius: 8px; overflow: hidden; color: rgba(0, 0, 0, 0.8); font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><div data-bm="46" style="display: flex; height: 28px; flex-direction: row; justify-content: space-between; align-items: center; gap: 8px; padding: 8px 12px; border-bottom: 1px solid rgba(0, 0, 0, 0.1); background: none 0% 0% / auto repeat scroll padding-box border-box rgb(247, 240, 255);"><h5 style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: 0px; padding: revert; font-style: inherit; font-variant: inherit; font-weight: 700; font-stretch: inherit; line-height: 18px; font-family: inherit; font-optical-sizing: inherit; font-size-adjust: inherit; font-kerning: inherit; font-feature-settings: inherit; font-variation-settings: inherit; font-size: 16px; display: inline-block; color: rgb(83, 41, 130);">Csharp</h5><div style="height: 28px;"><button type="button" tabindex="" title="Copy code" style="box-sizing: border-box; margin: 0px; padding: 0px; font: 400 13px / 20px Roboto, Helvetica, sans-serif; background-color: rgb(223, 211, 237); border-color: rgba(0, 0, 0, 0); border-style: solid; border-width: 1px; border-image: none 100% / 1 / 0 stretch; display: grid; grid-auto-flow: column; align-items: center; gap: 4px; cursor: pointer; color: rgb(83, 41, 130) !important; text-decoration: none !important; border-radius: 9999px; padding-block: 3px; padding-inline: 8px;"><div style="box-sizing: border-box; margin: 0px; padding: 0px; min-inline-size: 0px; white-space: nowrap; overflow: clip; text-overflow: ellipsis; max-block-size: calc(1lh);">Copy code</div></button></div></div><code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255); display: block; white-space: pre-wrap; overflow-wrap: anywhere; padding: 8px 16px 16px;">using System.IO;
using System.Linq;
using Microsoft.EntityFrameworkCore;

public class YourDbContext : DbContext
{
 public DbSet&lt;Category&gt; Categories { get; set; }

 protected override void OnModelCreating(ModelBuilder modelBuilder)
 {
 base.OnModelCreating(modelBuilder);

 // wwwroot/images フォルダのパスを取得
 var imageFolderPath = Path.Combine(Directory.GetCurrentDirectory(), &quot;wwwroot&quot;, &quot;images&quot;);

 if (Directory.Exists(imageFolderPath))
 {
 // フォルダ内のすべての .png ファイルを取得
 var imageFiles = Directory.GetFiles(imageFolderPath, &quot;*.png&quot;);

 // データを格納するリストを作成
 var categories = imageFiles.Select((filePath, index) =&gt; new Category
 {
 Id = index + 1, // IDを1から順に割り当て
 CategoryName = Path.GetFileNameWithoutExtension(filePath), // 拡張子を除いたファイル名
 CategoryImage = File.ReadAllBytes(filePath) // 画像ファイルをバイト配列に変換
 }).ToList();

 // モデルにデータをシード
 modelBuilder.Entity&lt;Category&gt;().HasData(categories);
 }
 }
}

public class Category
{
 public int Id { get; set; }
 public string CategoryName { get; set; }
 public byte[] CategoryImage { get; set; }
}
</code></pre><h3 data-bm="41" style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert; display: inline-block; font: 20px / 22px Roboto, sans-serif; color: rgba(0, 0, 0, 0.8); letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">説明</h3><ol data-bm="42" style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert; color: rgba(0, 0, 0, 0.8); font-family: Roboto, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;"><p style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: 8px 0px; padding: revert; -webkit-line-clamp: revert;"><code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">Directory.GetCurrentDirectory()</code>:<ul style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert;"><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;">現在のプロジェクトのルートディレクトリを取得します。</li><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;">ここから&nbsp;<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">wwwroot/images</code> フォルダのパスを構築します。</li></ul></li><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;"><p style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: 8px 0px; padding: revert; -webkit-line-clamp: revert;"><code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">Directory.GetFiles</code>:<ul style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert;"><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;">指定したフォルダ内の&nbsp;<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">.png</code> ファイルをすべて取得します。</li></ul></li><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;"><p style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: 8px 0px; padding: revert; -webkit-line-clamp: revert;"><code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">Path.GetFileNameWithoutExtension</code>:<ul style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert;"><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;">ファイル名から拡張子を除去し、<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">CategoryName</code> に格納します。</li></ul></li><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;"><p style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: 8px 0px; padding: revert; -webkit-line-clamp: revert;"><code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">File.ReadAllBytes</code>:<ul style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert;"><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;">画像ファイルをバイト配列に変換し、<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">CategoryImage</code> に格納します。</li></ul></li><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;"><p style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: 8px 0px; padding: revert; -webkit-line-clamp: revert;"><code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">HasData</code>:<ul style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert;"><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;"><code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">OnModelCreating</code> 内でデータをシードするために使用します。</li></ul></li></ol><h3 data-bm="43" style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert; display: inline-block; font: 20px / 22px Roboto, sans-serif; color: rgba(0, 0, 0, 0.8); letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">注意点</h3><ul data-bm="44" style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert; color: rgba(0, 0, 0, 0.8); font-family: Roboto, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;"><p style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: 8px 0px; padding: revert; -webkit-line-clamp: revert;"><code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">wwwroot</code> フォルダの画像ファイル:<ul style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert;"><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;">必ず&nbsp;<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">wwwroot/images</code> フォルダに画像ファイルを配置してください。</li></ul></li><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;"><p style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: 8px 0px; padding: revert; -webkit-line-clamp: revert;">マイグレーションの再作成:<ul style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: revert; padding: revert;"><li style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin-top: revert; margin-right: revert; margin-bottom: 8px; margin-left: revert; padding: revert;">このコードを適用した後、<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">Add-Migration</code> と&nbsp;<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">Update-Database</code> を実行してデータベースを更新してください。</li></ul></li></ul><p data-bm="45" style="border: 0px; border-collapse: collapse; border-spacing: 0px; list-style-position: initial; list-style-image: initial; list-style-type: revert; margin: 8px 0px; padding: revert; -webkit-line-clamp: revert; color: rgba(0, 0, 0, 0.8); font-family: Roboto, Helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">このコードを使えば、<code style="border-radius: 8px; background: none 0% 0% / auto repeat scroll padding-box border-box rgb(255, 255, 255);">wwwroot/images</code> 内の複数の画像ファイルをデータベースに格納し、それぞれのファイル名（拡張子なし）とバイト配列を対応付けることができます！

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