欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  移动技术

windows phone开发之图片上传

程序员文章站 2022-08-12 20:17:16
首先是 后台类 [csharp] ///   /// 上传文件  ///  ...

首先是 后台类

[csharp]
/// <summary> 
/// 上传文件 
/// </summary> 
public class UploadFile 

    public UploadFile() 
    { } 
    /// <summary> 
    /// 根据文件名、文件类型与文件流实现化 
    /// </summary> 
    /// <param name="fileName">文件名</param> 
    /// <param name="stream">文件数据流</param> 
    public UploadFile(string fileName, Stream stream) 
    { 
        this.FileName = System.IO.Path.GetFileName(fileName); 
        this.ContentType = GetContentType(this.FileName); 
        this.FileStream = stream; 
    } 
 
    /// <summary> 
    /// 文件名称 
    /// </summary> 
    public string FileName { get; private set; } 
 
    /// <summary> 
    /// 文件类型 
    /// </summary> 
    public string ContentType { get; private set; } 
 
    /// <summary> 
    /// 本地文件路径 
    /// </summary> 
    private string FilePath { get; set; } 
    /// <summary> 
    /// 文件数据流 
    /// </summary> 
    public Stream FileStream { get; private set; } 
 
    /// <summary> 
    /// 将当前的文件数据写入到某个数据流中 
    /// </summary> 
    /// <param name="stream"></param> 
    public void WriteTo(Stream stream) 
    { 
        byte[] buffer = new byte[512]; 
        int size = 0; 
 
        if (this.FileStream != null) 
        { 
            //写入文件流 
            while ((size = this.FileStream.Read(buffer, 0, buffer.Length)) > 0) 
            { 
                stream.Write(buffer, 0, size); 
            } 
        } 
 
        if (!string.IsNullOrEmpty(this.FilePath) 
            && File.Exists(this.FilePath)) 
        { 
            //写入本地文件流 
            using (System.IO.FileStream reader = new FileStream(this.FilePath, FileMode.Open, FileAccess.Read)) 
            { 
                while ((size = reader.Read(buffer, 0, buffer.Length)) > 0) 
                { 
                    stream.Write(buffer, 0, size); 
                } 
            } 
        } 
 
    } 
 
    /// <summary> 
    /// 根据文件扩展名获取文件类型 
    /// </summary> 
    /// <param name="fileName">文件名</param> 
    /// <returns></returns> 
    private static string GetContentType(string fileName) 
    { 
        var fileExt = System.IO.Path.GetExtension(fileName); 
        return GetCommonFileContentType(fileExt); 
    } 
    /// <summary> 
    /// 获取通用文件的文件类型 
    /// </summary> 
    /// <param name="fileExt">文件扩展名.如".jpg",".gif"等</param> 
    /// <returns></returns> 
    private static string GetCommonFileContentType(string fileExt) 
    { 
        switch (fileExt) 
        { 
            case ".jpg": 
            case ".jpeg": 
                return "image/jpeg"; 
            case ".gif": 
                return "image/gif"; 
            case ".bmp": 
                return "image/bmp"; 
            case ".png": 
                return "image/png"; 
            default: 
                return "application/octetstream"; 
        } 
    } 
 
    /// <summary> 
    /// 压缩图片,只调整质量,不调整分辨率 
    /// </summary> 
    /// <param name="soucre">图片流</param> 
    /// <param name="quality">质量1-100</param> 
    public static Stream Compression(Stream soucre) 
    { 
        var quality = 80; 
        soucre.Seek(0, SeekOrigin.Begin); 
        var p = quality / 100.0; 
        var writeableBitmap = PictureDecoder.DecodeJpeg(soucre); 
        var width = writeableBitmap.PixelWidth * p; 
        var height = writeableBitmap.PixelHeight * p; 
        var outstream = new MemoryStream(); 
        writeableBitmap.SaveJpeg(outstream, (int)width, (int)height, 0, quality); 
        outstream.Seek(0, SeekOrigin.Begin); 
        return outstream; 
    }  

然后是前台的调用
[csharp]
/// <summary> 
       /// 图片上传处理 
       /// </summary> 
       /// <param name="sender"></param> 
       /// <param name="e"></param> 
       private void PhotoChooserTask_Completed(object sender, PhotoResult e) 
       { 
           try 
           { 
               if (e.ChosenPhoto != null) 
               { 
                   Stream s = UploadFile.Compression(e.ChosenPhoto); 
                   bytepic = StreamToBytes(s); 
                   Encoding myEncoding = Encoding.GetEncoding("utf-8"); 
                   strpic = Convert.ToBase64String(bytepic); 
                   ExistsPic = true; 
               } 
           } 
           catch (Exception) 
           { 
               throw; 
           } 
       } 
       /// <summary> 
       /// 字节流转换byte 
       /// </summary> 
       /// <param name="stream"></param> 
       /// <returns></returns> 
       public byte[] StreamToBytes(Stream stream) 
       { 
           byte[] bytes = new byte[stream.Length]; 
           stream.Read(bytes, 0, bytes.Length); 
           // 设置当前流的位置为流的开始  
           stream.Seek(0, SeekOrigin.Begin); 
           return bytes; 
       } 


作者 fengyarongaa