將文本文件轉換爲圖像以便在.NET中進行預覽

Question

我遇到以下情況，需要將文本文件（文本文件蒸汽）轉換爲小圖像，然後將它們存儲在數據庫（SQL Server）中，以便稍後顯示在'預覽'屏幕中。任何人有任何建議如何做到這一點？特別是將文本文件轉換爲圖像？

Answer 1

我不認爲將文本文件轉換爲圖像是解決問題的最佳方法。這就是說，這裏有一些示例代碼來幫助你入門。

using System.Drawing; 
using System.Drawing.Drawing2D; 
using System.Drawing.Imaging; 
using System.IO; 
using System.Linq; 

/// <summary> 
/// A utility class to generate images from a string. 
/// </summary> 
public static class ImageMaker 
{ 
    private static readonly ImageCodecInfo MyCodecInfo = GetEncoderInfo("image/jpeg"); 
    private static readonly EncoderParameters MyEncodeParameters = new EncoderParameters(1); 

    static ImageMaker() 
    { 
     // Specify the quality for generated images. 
     MyEncodeParameters.Param[0] = new EncoderParameter(Encoder.Quality, 95L); 
    } 

    /// <summary> 
    /// Takes in a string and returns an image of that text. 
    /// </summary> 
    /// <param name="text">Text to put on an image.</param> 
    /// <returns>Image instance.</returns> 
    public static Image DrawText(string text) 
    { 
     // Create a bitmap to store the result. 
     var destImage = new Bitmap(500, 700); 

     // Create a graphic to draw the text on. 
     Graphics graphic = Graphics.FromImage(destImage); 
     graphic.FillRectangle(new SolidBrush(Color.White), 0, 0, destImage.Width, destImage.Height); 

     graphic.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality; 
     graphic.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; 
     graphic.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; 

     var fontFamily = new FontFamily("Arial"); 
     var textRectangle = new Rectangle(0, 0, destImage.Width, destImage.Height); 
     var format = new StringFormat(); 
     float emSize = graphic.DpiY * 10/72; 

     // Create text path. 
     var path = new GraphicsPath(); 
     path.AddString(text, fontFamily, (int)FontStyle.Regular, emSize, textRectangle, format); 

     // Write path to graphic. 
     var fillBrush = new SolidBrush(Color.FromKnownColor(KnownColor.Black)); 
     graphic.FillPath(fillBrush, path); 

     return destImage; 
    } 

    /// <summary> 
    /// Writes image to a stream. 
    /// </summary> 
    /// <param name="image">Image instance.</param> 
    /// <param name="stream">Stream instance.</param> 
    public static void WriteToStream(Image image, Stream stream) 
    { 
     image.Save(stream, MyCodecInfo, MyEncodeParameters); 
    } 

    /// <summary> 
    /// Gets codec info for the specified MIME type. 
    /// </summary> 
    /// <param name="mimeType">MIME type name.</param> 
    /// <returns>ImageCodecInfo instance or null if no matching info was found.</returns> 
    private static ImageCodecInfo GetEncoderInfo(string mimeType) 
    { 
     ImageCodecInfo[] encoders = ImageCodecInfo.GetImageEncoders(); 
     return encoders.FirstOrDefault(t => t.MimeType == mimeType); 
    } 
} 

而這裏的它是如何在一個ashx的處理程序使用的：

public class GetPreview : IHttpHandler 
{ 
    public void ProcessRequest(HttpContext context) 
    { 
     var image = ImageMaker.DrawText(
      @"Normally, both your asses would be dead as fucking fried chicken, " + 
      "but you happen to pull this shit while I'm in a transitional period so " + 
      "I don't wanna kill you, I wanna help you. But I can't give you this case, " + 
      "it don't belong to me. Besides, I've already been through too much " + 
      "shit this morning over this case to hand it over to your dumb ass."); 

     context.Response.ContentType = "image/jpeg"; 
     ImageMaker.WriteToStream(image, context.Response.OutputStream); 
    } 

    public bool IsReusable 
    { 
     get { return true; } 
    } 
} 

乾杯。

PS - 該lipsum文本從slipsum.com服用;）