Asp.net如何从数据库二进制字节到数据集查看图像到网格视图 [英] Asp.net how can I view image from database binary byte through dataset to grid view

问题描述

我正在尝试通过使用数据集在网格视图中显示从数据库中检索图像，

DB保存为字节



< b>我尝试了什么：

 <   pre  >  <   asp：GridView     ID   =  GridView1    runat   =  server    AutoGenerateColumns   =  False    DataKeyNames   =  Image_ID    DataSourceID   =  SqlDataSource2 >  
 <  列 >  
 <   asp：BoundField     DataField   =  CarID    HeaderText   =  CarID    SortExpression   =  CarID    /  >  
 <   asp：ImageField     DataAlternateTextField   =  Image_Front    DataImageUrlField   =  Image_Front    HeaderText   =  image front >  
 <   / asp：ImageField  >  
 <   /列 >  
 <   / asp：GridView  >  
 <   asp：SqlDataSource     ID   =  SqlDataSource2    runat   =  server    ConnectionString   =  <％ $ ConnectionStrings：DBConnectionString％>    SelectCommand   =  SELECT * FROM [Image] >  <   / asp：SqlDataSource  >  

解决方案

ConnectionStrings：DBConnectionString％> SelectCommand = SELECT * FROM [Image] > < / asp：SqlDataSource >

ASPX：



< pre lang =HTML> < asp：GridView runat = server ID = grd OnRowDataBound = grd_RowDataBound >
< 列 >
< asp：TemplateField HeaderText = image >
< ItemTemplate >
< img src =' <％ #Eval（ imagedata）％>' id = imageControl runat = server / >
< / ItemTemplate >
< / asp：TemplateField >
< /列 >
< / asp：GridView >

CS：



< pre lang =c＃> protected void grd_RowDataBound（ object sender，GridViewRowEventArgs e）
{
if （e.Row.RowType == DataControlRowType.DataRow）
{
System.Web.UI.HtmlControls.HtmlImage imageControl =（System.Web.UI.HtmlControls.HtmlImage）e.Row.FindControl（ imageControl ）;
if （（（DataRowView）e.Row.DataItem）[ imagedata]！= DBNull.Value）
{
imageControl.Src = data：image / png; base64， + Convert.ToBase64String（（ byte []）（（（DataRowView）e .Row.DataItem））[ imagedata]）;
}
}
}

BC for VB：

< pre>如果e.Row.RowType = DataControlRowType.DataRow那么
 Dim imageControl As System.Web.UI.HtmlControls.HtmlImage = CType（e .Row.FindControl（imageControl），System.Web.UI.HtmlControls.HtmlImage）
 
 If（CType（e.Row.DataItem，DataRowView））（imagedata）IsNot DBNull.Value然后
 imageControl.Src =data：image / png; base64，& Convert.ToBase64String（CType（（（CType（e.Row.DataItem，DataRowView）））（imagedata），Byte（）））
结束如果
结束如果

I'm trying to retrieve image from database through using dataset to show in grid view,
DB saved as byte

What I have tried:

<pre><asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="Image_ID" DataSourceID="SqlDataSource2">
            <Columns>
                <asp:BoundField DataField="CarID" HeaderText="CarID" SortExpression="CarID" />
                <asp:ImageField DataAlternateTextField="Image_Front" DataImageUrlField="Image_Front" HeaderText="image front">
                </asp:ImageField>
            </Columns>
        </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:DBConnectionString %>" SelectCommand="SELECT * FROM [Image]"></asp:SqlDataSource>

解决方案

ConnectionStrings:DBConnectionString %>" SelectCommand="SELECT * FROM [Image]"></asp:SqlDataSource>

ASPX:

<asp:GridView runat="server"  ID="grd" OnRowDataBound ="grd_RowDataBound"  >
                <Columns>
                    <asp:TemplateField HeaderText="image">
                        <ItemTemplate>
                          <img src='<%# Eval("imagedata") %>' id="imageControl" runat="server" />
                        </ItemTemplate>   
                    </asp:TemplateField> 
                </Columns>
</asp:GridView>

CS:

protected void grd_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if(e.Row.RowType==DataControlRowType.DataRow)
        {
            System.Web.UI.HtmlControls.HtmlImage imageControl = (System.Web.UI.HtmlControls.HtmlImage)e.Row.FindControl("imageControl");
            if (((DataRowView)e.Row.DataItem)["imagedata"] != DBNull.Value)
            {
                imageControl.Src = "data:image/png;base64," + Convert.ToBase64String((byte[])(((DataRowView)e.Row.DataItem))["imagedata"]);
            }
        }
    }

BC for VB:

<pre>If e.Row.RowType = DataControlRowType.DataRow Then
            Dim imageControl As System.Web.UI.HtmlControls.HtmlImage = CType(e.Row.FindControl("imageControl"), System.Web.UI.HtmlControls.HtmlImage)

            If (CType(e.Row.DataItem, DataRowView))("imagedata") IsNot DBNull.Value Then
                imageControl.Src = "data:image/png;base64," & Convert.ToBase64String(CType(((CType(e.Row.DataItem, DataRowView)))("imagedata"), Byte()))
            End If
        End If

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