C# 圖片轉二進制/字符串 二進制/字符串反轉成圖片

    protected void Button1_Click(object sender, EventArgs e)

    {

        //圖片轉二進制

        byte[] imageByte = GetPictureData(Server.MapPath("./uploadfile/111.png"));

        //二進制轉換成字符串

        string picStr = Convert.ToBase64String(imageByte);

        //輸出字符串

        Response.Write(picStr);

        //字符串轉二進制

        byte[] imageBytes = Convert.FromBase64String(picStr);

        //讀入MemoryStream對象

        MemoryStream memoryStream = new MemoryStream(imageBytes, 0, imageBytes.Length);

        memoryStream.Write(imageBytes, 0, imageBytes.Length);

        //二進制轉成圖片保存

        System.Drawing.Image image = System.Drawing.Image.FromStream(memoryStream);

        image.Save(Server.MapPath("./uploadfile/222.png"));

    }


/// <summary>  
/// 二進制流轉圖片  
/// </summary>  
/// <param name="streamByte">二進制流</param>  
/// <returns>圖片</returns>  
public System.Drawing.Image ReturnPhoto(byte[] streamByte)  
{  
    System.IO.MemoryStream ms = new System.IO.MemoryStream(streamByte);  
    System.Drawing.Image img = System.Drawing.Image.FromStream(ms);  
    return img;  
}  

/// <summary>  
/// 圖片轉二進制  
/// </summary>  
/// <param name="imagepath">圖片地址</param>  
/// <returns>二進制</returns>  
public byte[] GetPictureData(string imagepath)  
{  
    //根據圖片文件的路徑使用文件流打開，并保存為byte[]   
    FileStream fs = new FileStream(imagepath, FileMode.Open);//可以是其他重載方法   
    byte[] byData = new byte[fs.Length];  
    fs.Read(byData, 0, byData.Length);  
    fs.Close();  
    return byData;  
}  

/// <summary>  
/// 圖片轉二進制  
/// </summary>  
/// <param name="imgPhoto">圖片對象</param>  
/// <returns>二進制</returns>  
public byte[] PhotoImageInsert(System.Drawing.Image imgPhoto)  
{  
    //將Image轉換成流數據，并保存為byte[]   
    MemoryStream mstream = new MemoryStream();  
    imgPhoto.Save(mstream, System.Drawing.Imaging.ImageFormat.Bmp);  
    byte[] byData = new Byte[mstream.Length];  
    mstream.Position = 0;  
    mstream.Read(byData, 0, byData.Length);  
    mstream.Close();  
    return byData;  
}  </pre>