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代碼更新圖像的URL我有這個頁面:如何動態地從後面
<form id="form1" runat="server">
<asp:Image id="imgLogo" runat="server" />
<div class="content">
<asp:ScriptManager ID="scrptMan" runat="server"></asp:ScriptManager>
<asp:UpdatePanel ID="updChooser" runat="server">
<ContentTemplate>
<h3>Company name</h3>
<asp:DropDownList ID="ddCompany" runat="server" DataTextField="CompanyName" DataValueField="Id" AutoPostBack="true" OnSelectedIndexChanged="ddCompany_OnSelectedIndexChanged"></asp:DropDownList>
<h3>Year</h3>
<asp:DropDownList ID="ddYear" runat="server" AutoPostBack="true" OnSelectedIndexChanged="ddYear_OnSelectedIndexChanged"></asp:DropDownList>
<asp:Literal ID="ltAdvice" runat="server"></asp:Literal>
<strong><asp:Literal ID="ltYear" runat="server"></asp:Literal></strong>
<asp:Panel ID="pnlNext" runat="server" Visible="false">
<div class="submit">
<asp:Button ID="btnNext" runat="server" Text="Next" CssClass="button" OnClick="btnNext_OnClick"/>
</div>
</asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
我要動態更新從代碼標誌形象的背後,如果用戶選擇的公司,這樣的
private void FillLogo(int companyId)
{
//temporary
byte[] logo = File.ReadAllBytes(@"D:\temp\images\baseLogo.png");
if (clientId > 0 && File.Exists(@"D:\temp\images\companies\" + companyId + ".png"))
{
logo = File.ReadAllBytes(@"D:\temp\images\companies\" + companyId+ ".png");
}
imgLogo.ImageUrl = "data:image/jpeg;base64," + Convert.ToBase64String(logo);
}
我在ddCompany_OnSelectedIndexChanged方法中調用此方法,並在具有正確的公司ID的OnPreRender方法中調用此方法,但第一次加載徽標並且ddCompany中的任何更改都不會更新。 完全可以實現?