Question

嗨我试图从数据库中获取一个字节数组，并将其转换为我可以用来从我的.aspx页面中的数据库显示图像的东西。我严格使用C＃。

这是我的代码。

SqlCommand picCommand = connection.CreateCommand(); 
picCommand.CommandText = ("SELECT ItemImage FROM Inventory WHERE ItemName = '" +   DropDownList1.SelectedItem.Text + "';"); 
connection.Open(); 

object returnPic; 
returnPic = picCommand.ExecuteScalar();//value that is read as the byte array or intended to be read as byte array. 


    connection.Close(); 


    UTF8Encoding utf8 = new UTF8Encoding(); 
    //where i intend to convert the 
    byte[] image = utf8.GetBytes(returnPic.ToString()); 


    System.Drawing.Image myImage; 

    using (MemoryStream inStream = new MemoryStream()) 
    { 
     inStream.Write(image, 0, image.Length); 

     myImage = Bitmap.FromStream(inStream); 
    } 




    this.ItemImageBox.Equals(myImage); 

的代码可以编译和运行，但是当它到达的地方执行行 MYIMAGE = Bitmap.FromStream（插播广告）我得到这个错误System.ArgumentException点：参数是无效的。实际上，我通过查看各种不同的来源获得了这些代码，所以也许有人在这里可以告诉我，如果我做错了什么。

谢谢！

Answer 1

，你可以尝试这样的事情，它应该为你

public static Image LoadImage(byte[] imageBytes) 
{ 
    Image image = null; 
    using (var inStream = new MemoryStream(imageBytes)) 
    { 
     image = Image.FromStream(ms); 
    } 
    return image; 
} 

Answer 2

在这里工作是一个扩展方法我有一个字节数组转换为位图 在这个例子中，我用我保存数据到SQL SERVER数据库2008R2

protected void btnParent1Upload_Click(object sender, EventArgs e) 
    { 
     ScriptManager.GetCurrent(this).RegisterPostBackControl(this.btnParent1Upload); 
     FileUpload FileUpload1 = file_ImageParent1; 
     string virtualFolder = "~/UpImages/"; 
     string physicalFolder = Server.MapPath(virtualFolder); 
     FileUpload1.SaveAs(physicalFolder + FileUpload1.FileName); 
     lbl_ResultParent1.Text = "Your file " + FileUpload1.FileName + " has been uploaded."; 
     Parent1Pic.Visible = true; 
     Parent1Pic.ImageUrl = virtualFolder + FileUpload1.FileName; 
     byte[] imageBytes = PopulateImageBytes(physicalFolder + FileUpload1.FileName); 
     ParentsInfo.Parent1Pic = imageBytes; 
     imageBytes = null; 
     FileUpload1 = null; 
    } 

    private static byte[] PopulateImageBytes(string p) 
    { 
     byte[] imageBytes = File.ReadAllBytes(p); 
     return imageBytes; 
    } 

我已经StudentPic定义如下

public byte[] StudentPic { get; set; } 

我有我的SQL PARAMS之一定义为以下

sqlcmd.Parameters.AddWithValue("@Picture", (object)StudentPic ?? noImage); 

这会帮助你了解不同的方法可以做到这一个