我的数据库中有一个图像的二进制数据，我想在ASP.NET中的图像控件中显示它。如何？如果不可能，请找到另一种方法将其保存在数据库中，并在图像控件中显示。
创建一个常规HTML img元素，如下所示：
<img runat="server" id="image" />
在代码背后这样做：
image.src = "data:image/png;base64," + Convert.ToBase64String(imageBytes);
其中imageBytes是byte[]。
你完了。将显示图像。
图像很可能以字节数组的形式存储在数据库中。如果是这样，那么你可以使用这个：
public static System.Drawing.Image ByteArrayToImage(byte[] bArray)
{
if (bArray == null)
return null;
System.Drawing.Image newImage;
try
{
using (MemoryStream ms = new MemoryStream(bArray, 0, bArray.Length))
{
ms.Write(bArray, 0, bArray.Length);
newImage = System.Drawing.Image.FromStream(ms, true);
}
}
catch (Exception ex)
{
newImage = null;
//Log an error here
}
return newImage;
}
public Byte[] Ret_image(Int32 id)
{
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "select * from tbimage where imageid=@id";
cmd.Connection = con;
cmd.Parameters.Add("@id", SqlDbType.Int).Value = id;
SqlDataReader dr = cmd.ExecuteReader();
dr.Read();
Byte[] ar = (Byte[])(dr[1]);
dr.Close();
cmd.Dispose();
return ar;
}
protected void Button2_Click(object sender, EventArgs e)
{
Byte[] ar = Ret_image(Convert.ToInt32(TextBox2.Text));
String st = Server.MapPath("abc.jpg");
FileStream fs = new FileStream(st, FileMode.Create, FileAccess.Write);
fs.Write(ar, 0, ar.Length);
fs.Close();
Image1.ImageUrl = "abc.jpg";
}
将此事件用于按钮单击以检索图像并在此处调用Ret_Image方法。
在通用处理程序(.ashx(中：
public class ImageHandler : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
if(!string.IsNullOrEmpty(context.Request.QueryString["ImageId"]))
{
try
{
string ImageId = context.Request.QueryString["ImageId"].ToString();
ImageDataModel idm = new ImageDataModel();
byte[] ImageData = idm.getImageData(ImageId);
context.Response.ContentType = "image/JPEG";
context.Response.OutputStream.Write(ImageData, 0, ImageData.Length);
}
catch(Exception ex){}
}
}
}
SqlConnection con = new SqlConnection();
string _path;
Using SYstem.IO;
Using System.Data.SQLClient;
//convert Image to binary and save in DB
private void button1_Click(object sender, EventArgs e)
{
if (openFileDialog1.ShowDialog() == DialogResult.OK)
{
_path = openFileDialog1.FileName;
InsertInSQL(_path);
}
}
private void InsertInSQL(string _path)
{
con.ConnectionString = Pic.Properties.Settings.Default.ConnectionS;
string strQ = "insert into dbo.PicTBL(Pic)values(@p)";
SqlCommand command = new SqlCommand(strQ,con);
command.Parameters.AddWithValue("@p",ImageToBinary(_path));
con.Open();
command.ExecuteNonQuery();
con.Close();
}
public static byte[] ImageToBinary(string _path)
{
FileStream fS = new FileStream(_path, FileMode.Open, FileAccess.Read);
byte[] b = new byte[fS.Length];
fS.Read(b, 0, (int)fS.Length);
fS.Close();
return b;
}
//Convert Binary to imge and save in a folder
private void button1_Click_1(object sender, EventArgs e)
{
DataTable dt = Rimage();
foreach (DataRow row in dt.Rows)
{
byte[] b = (byte[])row["Pic"];
Image img = BinaryToImage(b);
img.Save("D:\NewFolder\" + row["ID"].ToString() + ".jpg");
}
}
private Image BinaryToImage(byte[] b)
{
if (b == null)
return null;
MemoryStream memStream = new MemoryStream();
memStream.Write(b, 0, b.Length);
return Image.FromStream(memStream);
}
private DataTable Rimage()
{
con.ConnectionString = Pic.Properties.Settings.Default.ConnectionS;
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "select * from dbo.PicTBL";
cmd.Connection = con;
SqlDataAdapter adp = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
con.Open();
adp.Fill(dt);
return dt;
}