ASP.NET-如何在浏览器中显示图像而不在临时中保存图像

本文关键字：图像 保存 显示 NET- 浏览器 ASP 显示图 | 更新日期: 2023-09-27 18:22:16

我有一个问题-如何在浏览器中显示图像而不将图像保存在Temp文件夹中？这可能吗？我的代码必须从数据库中读取图像并在网站中显示图像。实际上，我试着从数据库中转换数据，但我不知道我想做什么。我也尝试使用"imageHandlers"、"FileStream"、"Base64StringToBitmap"，但仍然没有任何效果。。。请编写示例代码或修改我的代码。

private void LoadImages()
{
ImageButton imageButton = new ImageButton();
string constr = ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString;
using (SqlConnection conn = new SqlConnection(constr))
{
    using (SqlCommand cmd = new SqlCommand())
    {
        cmd.CommandText = "select Id, Name, Data from tblFiles WHERE email = @CurrentUser";
        cmd.Parameters.Add("@CurrentUser", SqlDbType.NVarChar);
        cmd.Parameters["@CurrentUser"].Value = User.Identity.Name;
        cmd.Connection = conn;
        conn.Open();
        using (SqlDataReader sdr = cmd.ExecuteReader())
        {
            if (sdr.HasRows)
            {
                sdr.Read();
                string fileName = sdr["Name"].ToString();
                FileInfo fi = new FileInfo(fileName);
                byte[] byte_image_string = ((byte[])sdr["Data"]);
                string image_string = Convert.ToBase64String((byte[])sdr["Data"]) + fi.Name;
                imageButton.Height = Unit.Pixel(100);
                imageButton.Style.Add("padding", "5px");
                imageButton.Width = Unit.Pixel(100);
                imageButton.Click += new ImageClickEventHandler(imageButton_Click);
                Panel1.Controls.Add(imageButton);
                System.Drawing.Image newImage;
                if (byte_image_string != null)
                {
                    using (MemoryStream stream = new MemoryStream(byte_image_string))
                    {
                        newImage = System.Drawing.Image.FromStream(stream);
                        //I want here display image to browser without saving
                        //string newPhoto = "";
                        //newImage.Save(newPhoto);
                        imageButton.ImageUrl = "data:image/jpg;base64," + newPhoto;
                    }   
                }   
                conn.Close();
            }
        }    
    }
}
}

我的数据库图像代码示例：

0xFFD8FFE0000104A46494600010100000100010000FFE1018C45786966000049492A000000000200310102000700000026000000698704000010000002E00000000000000476F6F676C6500000000900700000030323230099007000000007000000008692070000000007B00000002A0040010000000006F000003A0

ASP.NET-如何在浏览器中显示图像而不在临时中保存图像

我在一个项目中就是这样做的：Look src part

<p><a href='<%#"TheObject.aspx?O=" + Eval("ID") %>'><img runat="server" visible='<%#Eval("AttachmentID") != DBNull.Value %>' class="objPicture1" alt='<%Eval("Title") %>' width="340" height="260" src='<%#"~/Attachment.aspx?ID=" + Eval("AttachmentID")%>' /></a></p>

在Attachment.aspx中，您有以下代码：

    protected void Page_Load(object sender, EventArgs e)
    {
        Guid objID = //take the ID of the object ?ID=""
        DataRow attachmentRow = //fetch DataRow of the Attachment from Database
        if (attachmentRow == null)
            return;
        Response.ContentType = attachmentRow["ContentType"].ToString();// value of this is image/gif or image/jpeg and etc.
        Response.BinaryWrite((byte[])attachmentRow["Data"]); // Data is type image in my case                
        Response.End();
    }

看起来您以错误的方式创建Base64String。您正在将文件名附加到它上，这不应该起作用。试着跟随。

string image_string = Convert.ToBase64String((byte[])sdr["Data"]);

直接分配给ImageUrl。这里不需要使用CCD_ 3。

imageButton.ImageUrl = "data:image/jpg;base64," + image_string;
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