[ASP.NET] プロ生ちゃん壁紙ジェネレーター 2
先日の プロ生ちゃん 壁紙ジェネレーター 2 のコードを公開しておきます。いわゆる classic ASP.NET (Web forms) です。
サーバー側で画像を合成してます。HTML5 + JavaScript で合成は、プロ生ちゃん アイコンジェネレーター などを見てください。
壁紙ジェネレーター ASP.NET Tips
コードのポイントをまとめておきます。
GET パラメータークエリーの取得と URL か判定
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| Dim q = Context.Request.QueryString.Get("q") | |
| If Not Uri.IsWellFormedUriString(q, UriKind.Absolute) Then | |
| Exit Sub | |
| End If | |
| Dim url = New Uri(q) |
URL から Bitmap の生成
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| Dim webBmp As Bitmap | |
| Using wc = New WebClient | |
| webBmp = New Bitmap(wc.OpenRead(url)) | |
| End Using |
サーバーのディレクトリにある画像の読み込み
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| Dim wallBmp = New Bitmap(System.IO.Path.Combine(Server.MapPath("./"), "wallpaper.png")) |
描画先の範囲に合せて、画像の合成
左右・上下に空きがないよう、Web 画像を拡大・縮小して必要な範囲を描画します。
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| Dim dst = New Rectangle(754, 18, 1110, 807) ' 描画先の位置・大きさ | |
| Dim src = New Rectangle(0, 0, webBmp.Width, webBmp.Height) ' 参照画像の位置・大きさ | |
| If dst.Width / dst.Height < webBmp.Width / webBmp.Height Then | |
| Dim w = dst.Width / (dst.Height / webBmp.Height) | |
| src.X = Convert.ToInt32((webBmp.Width – w) / 2) | |
| src.Width = Convert.ToInt32(w) | |
| Else | |
| Dim h = dst.Height / (dst.Width / webBmp.Width) | |
| src.Y = Convert.ToInt32((webBmp.Height – h) / 2) | |
| src.Height = Convert.ToInt32(h) | |
| End If | |
| Dim wallBmp = New Bitmap(System.IO.Path.Combine(Server.MapPath("./"), "wallpaper.png")) | |
| Dim outBmp = New Bitmap(wallBmp.Width, wallBmp.Height) | |
| Using g = Graphics.FromImage(outBmp) | |
| g.CompositingQuality = Drawing2D.CompositingQuality.HighQuality | |
| g.DrawImage(webBmp, dst, src, GraphicsUnit.Pixel) | |
| g.DrawImage(wallBmp, 0, 0, wallBmp.Width, wallBmp.Height) | |
| End Using |
Content-Type image/png としてレスポンスを返す（画像の出力）
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| Response.ContentType = "image/png" | |
| Response.Flush() | |
| outBmp.Save(Response.OutputStream, Imaging.ImageFormat.Png) | |
| Response.End() |
Web に配置したとき、パーサーエラーと表示される
「パーサー エラー メッセージ: 型 '○○○’ を読み込めませんでした。」と表示される場合、aspx ファイルの CodeBehind を CodeFile に変更します。
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| <%@ Page Language="vb" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="GeneratorWebForm" %> |