所以我填充了数据表但是我需要图像数据的列不起作用。我可以看到填充的表，可以看到它正在读取数据，但不是作为字节数组，也不是显示图像。
public void Bindformview()
{
try
{
SqlDataAdapter adp = new SqlDataAdapter("Select * from Recipes", con);
DataTable dt = new DataTable();
adp.Fill(dt);
if (dt.Rows.Count > 0)
{
FormViewRecipes.DataSource = dt;
FormViewRecipes.DataBind();
}
else
{
FormViewRecipes.DataSource = null;
FormViewRecipes.DataBind();
}
}
我知道我需要插入这个代码，或类似的东西，将数据从db＆＃34; thumbnail varbinary（MAX）＆＃34;中提取出来。列作为字节流，以获取正确显示图像的字节数组：
DataColumn column = new DataColumn("MyImage"); //Create the column.
column.DataType = System.Type.GetType("System.Byte[]"); //Type byte[] to store image bytes.
column.AllowDBNull = true;
column.Caption = "My Image";
table.Columns.Add(column); //Add the column to the table.
和此：
DataRow row = table.NewRow();
row["MyImage"] = <Image byte array>;
tables.Rows.Add(row);
但我不需要新列或新行，因为那些字段已经存在。 那么如何填写专栏＃34; Thumbnail＆＃34;在数据表中，要显示字节数组数据，在if绑定dt的if语句中，在加载dt的if语句之前，我在哪里插入所述代码？
我是这样写的，如下所示：
dt.column.thumbnail.fill(byte[] bytes = (byte[])cmd.ExecuteScalar());
然后把它放进来填写formview image1 ID吗？
string strBase64 = Convert.ToBase64String(bytes);
formviewrecipes.Image1.ImageUrl = "data:Image/png;base64," + strBase64;
我处于停滞状态，不知道如何做到这一点。
所以要清楚，我已经拥有了具有正确图像信息的数据库，并且可以通过<asp:image id=image1...etc />显示它，其他代码使用此代码在formview之外检索图像，
string cs = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
using (SqlConnection con = new SqlConnection(cs))
{
SqlCommand cmd = new SqlCommand("spGetImageByID", con);
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter paramId = new SqlParameter()
{
ParameterName = "@Id",
Value = Request.QueryString["Id"]
};
cmd.Parameters.Add(paramId);
con.Open();
byte[] bytes = (byte[])cmd.ExecuteScalar();
string strBase64 = Convert.ToBase64String(bytes);
Image1.ImageUrl = "data:Image/png;base64," + strBase64;
}
}
但它在<asp:FormView...etc/>中无效，我需要能够将其用于页面格式化。
这就是为什么我正朝着这个方向前进，现在使用数据表。如果您有更好的解决方案，我愿意尝试它，只要它可以在<asp:formview />元素内部使用。谢谢。
答案 0 :(得分：0)
所以我明白了：
我需要在数据绑定Object o;
o = dt.Rows[0]["RecipeId"];和此行
喜欢如此：
if (dt.Rows.Count > 0)
{
FormViewRecipes.DataSource = dt;
FormViewRecipes.DataBind();
//lblDataTable.Text = dt.Rows.Count.ToString(); ---Used for testing-
o = dt.Rows[0]["RecipeId"];
}
else
{
FormViewRecipes.DataSource = null;
FormViewRecipes.DataBind();
}
}
并调用加载图像：
string cs = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
using (SqlConnection con = new SqlConnection(cs))
{
SqlCommand cmd = new SqlCommand("RETRIEVE_RECIPE", con);
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter paramId = new SqlParameter()
{
ParameterName = "@RecipeId",
Value = o //Object from the datatable
};
cmd.Parameters.Add(paramId);
con.Open();
byte[] bytes = (byte[])cmd.ExecuteScalar();
if (bytes != null)
{
string strBase64 = Convert.ToBase64String(bytes);
Image1.ImageUrl = "data:Image/png;base64," + strBase64;
}
else
{
Image1.ImageUrl = "~/images/NoImageAvail.jpg";
}
}
以下代码是否有其他人需要做同样的事情。我将把for / while或for / next组合在一起，以便同时显示多个数据库条目，而不是当前在<asp:forview...></formview>元素设置中一次显示。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Configuration;
using System.Data;
using System.IO;
using System.Data.SqlClient;
namespace DB_Test1
{
public partial class Search_Results_1 : System.Web.UI.Page
{
string b;
Object o;
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ToString());
protected void Page_Load(object sender, EventArgs e)
{
if (Request.QueryString["Search"] != null)
{
if (Request.QueryString["Text"] != null)
{
string a = Request.QueryString["Text"];
b = a;
recipeSearch(a);
}
}
}
protected void recipeSearch(string a)
{
//Search the database
con.Open();
try
{
SqlDataAdapter adp = new SqlDataAdapter("SELECT * FROM Recipes WHERE Type LIKE '%" + a + "%'", con);
DataTable dt = new DataTable();
adp.Fill(dt);
if (dt.Rows.Count > 0)
{
FormViewRecipes.DataSource = dt;
FormViewRecipes.DataBind();
//lblDataTable.Text = dt.Rows.Count.ToString(); ---Used for testing-
o = dt.Rows[0]["RecipeId"];
}
else
{
FormViewRecipes.DataSource = null;
FormViewRecipes.DataBind();
}
}
catch (Exception ex)
{
//throw new ApplicationException("operation failed!", ex);
}
con.Close();
FormViewRecipes.Visible = true;
string cs = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
using (SqlConnection con = new SqlConnection(cs))
{
SqlCommand cmd = new SqlCommand("RETRIEVE_RECIPE", con);
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter paramId = new SqlParameter()
{
ParameterName = "@RecipeId",
Value = o //Object from the datatable
};
cmd.Parameters.Add(paramId);
con.Open();
byte[] bytes = (byte[])cmd.ExecuteScalar();
if (bytes != null)
{
string strBase64 = Convert.ToBase64String(bytes);
Image1.ImageUrl = "data:Image/png;base64," + strBase64;
}
else
{
Image1.ImageUrl = "~/images/NoImageAvail.jpg";
}
}
Image1.Visible = true;
}
protected void FormViewRecipes_PageIndexChanging(object sender, FormViewPageEventArgs e)
{
string a = b;
FormViewRecipes.PageIndex = e.NewPageIndex;
recipeSearch(a);
}
}
}
这是ASPX页面代码：
<asp:Content ID="Content1" ContentPlaceHolderID="MainContent" runat="server">
<hr />
<div class="row">
<div class="col-md-8">
<table>
<tr>
<td>
<asp:Image ID="Image1" runat="server" visable="false" Height="150px" Width="150px"/>
</td>
<td>
<asp:FormView ID="FormViewRecipes" runat="server" DataKeyNames="RecipeId" AllowPaging="True"
onpageindexchanging="FormViewRecipes_PageIndexChanging" Visible="false">
<%--<FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
<RowStyle BackColor="#EFF3FB" />
<PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
<HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />--%>
<ItemTemplate>
<table style="border:1px solid #c1c1c1;">
<tr style="background-color:white;font-weight:bold"><td><%--Recipe Detail--%></td><td>
<%--<asp:Image id="Image1" runat="server" ImageUrl='<%# Eval("Thumbnail") %>'
AlternateText='<%# Eval("ThumbnailAltTxt") %>'
Height="100px" Width="100px" />--%></td>
</tr>
<tr><td><b>Title:- </b></td><td>
<asp:Label ID="lblRecipeTitle" runat="server" Text='<%# Eval("Title") %>'></asp:Label></td></tr>
<tr><td><b>Ingredients:- </b></td><td>
<asp:Label ID="lblIngredients" runat="server" Text='<%# Eval("Ingredients") %>'></asp:Label></td></tr>
<tr><td><b>Directions:- </b></td><td>
<asp:Label ID="lblDirections" runat="server" Text='<%# Eval("Directions") %>'></asp:Label></td></tr>
<tr><td><b>Notes:- </b></td><td>
<asp:Label ID="Label1" runat="server" Text='<%# Eval("Notes") %>'></asp:Label></td></tr>
</table>
</ItemTemplate>
<EmptyDataTemplate>
<table style="border:1px solid #c1c1c1;">
<tr style="background-color:#E5E5FE;font-weight:bold"><td><b>Recipe</b></td></tr>
<tr><td><b>Recipe Title:-</b></td><td style="color:Red;">No Records Aviable!</td></tr>
<tr><td><b>Recipe Ingredients:-</b></td><td style="color:Red;">No Records Aviable!</td></tr>
<tr><td><b>Recipe Directions:-</b></td><td style="color:Red;">No Records Aviable!</td></tr>
</table>
</EmptyDataTemplate>
</asp:FormView>
</td>
</tr>
</table>
</div>
<div class="col-md-4">
<p>Ad Space</p>
<asp:Label ID="lblDataTable" runat="server"></asp:Label>
</div>
</div>
</asp:Content>
请记住，我已注释掉<asp:image..../a>元素中的<Asp:formview.../>元素字段并重置我的页面布局，以了解我希望它如何寻找测试。