Question

我有一个数据库，我有一个表产品，我在那里保留产品的图片，在c＃中 public byte []图片

在我的数据库中，它是varbinary类型（自动转换）所以，我想要做的是在pictureBox1.Image中显示我的图像来自数据库;

 var q_pic = from p in context.Products
                         where p.ID == value // Id of product that i want 
                         select new
                         {
                             p.Picture
                         };

现在

picutreBox1.Image = ??

原因

pictureBox1.Image = q_pic doeasn't work

现在我有了这个

var bytes = from p in context.Products
                        where p.ID == value // Id of product that i want 
                        select p.Picture;
            if (bytes != null)
            {
                using (var ms = new MemoryStream(bytes))
                {
                    using (var image = Image.FromStream(ms))
                    {
                        pictureBox1.Image = (Image)image.Clone();
                    }
                }
            }

得到这个

Error   1   The best overloaded method match for 'System.IO.MemoryStream.MemoryStream(byte[])' has some invalid arguments   

Error   2   Argument 1: cannot convert from 'System.Linq.IQueryable<byte[]>' to 'byte[]'

Answer 1

你可能想要更像的东西：

var q_pic = from p in context.Products
                     where p.ID == value // Id of product that i want 
                     select p.Picture;

// FirstOrDefault will return null if there were no matches
pictureBox1.Image = q_pic.FirstOrDefault();

您原来的主要问题是您使用的是匿名类型（不必要），并尝试分配给IEnumerable<T>，而不仅仅是图片本身。从查询中删除new {...可解决第一个问题，并使用FirstOrDefault从T中提取单个IEnumerable<T>（第一个）。

鉴于您的评论，您的查询很明显会返回byte[]，而不是图片。你需要把它写成：

var first = context.Products.FirstOrDefault(p => p.ID == value);
if (first != null)
{
     using (var ms = new MemoryStream(first.Picture)) 
     {
         using(var image = Image.FromStream(ms)) 
         {
             pictureBox1.Image = (Image)image.Clone();
         }
     }
}

Answer 2

Reed Copsey列出的内容将帮助您找到Product对象上的byte []。要将它放在PictureBox的Image属性中，您需要将字节数组转换为Image。

 using (var ms = new System.IO.MemoryStream(q_pic)) {
    using(var img = Image.FromStream(ms)) {
       pictureBox1.Image = img;
    }
 }

Answer 3

使用LINQ时，从数据库中获取“System.Data.Linq.Binary”类型。此类型具有ToArray()方法，该方法返回byte[]。你应该纠正你这样的代码：

var bytes = from p in context.Products
                        where p.ID == value // Id of product that i want 
                        select p.Picture;
byte[] trueBytes = bytes.ToArray();
if (trueBytes != null)
{
    using (var ms = new MemoryStream(trueBytes))
    {
        using (var image = Image.FromStream(ms))
        {
            pictureBox1.Image = (Image)image.Clone();
        }
    }
}

Answer 4

只需制作

byte[] imgdata;


string id = dataGridViewX1.SelectedRows[0].Cells[0].Value.ToString();
var q = db.tbl_aezas.First(c => c.id == id);
imgdata = q.image.ToArray();
System.IO.MemoryStream ms = new System.IO.MemoryStream(imgdata);
pictureBox1.Image = Image.FromStream(ms);

Answer 5

DataBonzClinicDataContext db = new DataBonzClinicDataContext();

            var tsel = (from u in db.tblsysusers 
                       where (u.pass_id==cbxUser.Text.ToString().Trim()) 
                      select u.pass_imgid).First();            

            if (tsel != null)
            {
               var imgdata = tsel.ToArray();
                System.IO.MemoryStream ms = new System.IO.MemoryStream(imgdata);
                pictureBox1.Image = Image.FromStream(ms);
            }

使用LINQ查询从PictureBox中显示数据库中的图像

5 个答案: