查找动态创建的控件时出错
本文关键字:出错 控件 动态 创建 查找 | 更新日期: 2023-09-27 18:25:47
我使用Fileupload控件上传图像,加载文件后,当我单击"上传"按钮时,文件将保存在服务器中的文件夹中,但在保存到数据库之前,我需要在图像的同时添加图像描述。。但我不知道我犯了一些错误。我可以将文件保存在文件夹中,但当我将其保存到数据库中时,只会找到一个动态添加的控件,然后它会提供对象引用,而不是设置为对象的实例即使在特定的div中有多个控件。在进入代码之前,我会在上传文件后告诉我要添加哪些控件。。我正在为我上传的每个图像文件添加一个图像控件和文本框。。当我只上传一个文件时,它会在第一次上传后再次进入foreach循环。。我的代码可能会解释得更多。
这是我的.aspx代码:
<form id="ContentPlaceHolder1" runat="server">
<div class="transbox" id="mainbk" runat="server" style="position:absolute; top:0px; left:0px; width: 100%; height: 100%;" >
<asp:FileUpload runat="server" ID="UploadImages" style="background-color:white; position:absolute; font-family:'Palatino Linotype'; font-size:medium; top: 4px; left: 350px; right: 251px;" Width="500px" AllowMultiple="true"/>
<asp:Button runat="server" ID="uploadedFile" style="position:absolute; font-family:'Palatino Linotype'; font-size:medium; top: 4px; left: 870px; width: 112px; height: 29px;" Text="Upload" OnClick="uploadFile_Click" />
<asp:Panel ID="updtpanel" runat="server" CssClass="transbox" style="width:100%;height:100%;left:0px;top:0px;position:absolute" Visible="false">
<asp:Button ID="btnsave" runat="server" UseSubmitBehavior="true" Text="Save" OnClick="btnsave_Click" Font-Bold="true" BackColor="Yellow"></asp:Button>
</asp:Panel>
</div>
</form>
这是我的后端代码。
SqlCommand com = new SqlCommand();
SqlConnection con = new SqlConnection();
SqlDataReader reader;
int id = 0;
StringBuilder sb = new StringBuilder();
string filepath = "";
string newpath = "";
int tid = 0;
int count = 0;
int cnt1 = 0;
string textid = "";
Panel dload;
Image img;
TextBox ta;
protected void Page_Load(object sender, EventArgs e)
{
con.ConnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
con.Open();
com = new SqlCommand("select max(slid) from slider", con);
reader = com.ExecuteReader();
if (reader.HasRows)
{
while (reader.Read())
{
id = Convert.ToInt32(reader.GetInt32(0));
}
}
con.Close();
com.Dispose();
HtmlGenericControl dh = new HtmlGenericControl("div");
dh.Attributes.Add("class", "head");
dh.InnerText = "Write Description";
updtpanel.Controls.Add(dh);
foreach (HttpPostedFile upld in UploadImages.PostedFiles)
{
createImgPanel();
}
}
protected void uploadFile_Click(object sender, EventArgs e)
{
if (UploadImages.HasFiles)
{
string fileExt = Path.GetExtension(UploadImages.FileName).ToLower();
if (fileExt == ".jpeg" || fileExt == ".png" || fileExt == ".jpg" || fileExt == ".bmp")
{
foreach (HttpPostedFile uploadedFile in UploadImages.PostedFiles)
{
count += 1;
filepath = Server.MapPath("~/Images/Gallery/" + uploadedFile.FileName);
uploadedFile.SaveAs(filepath);
newpath = "../Images/Gallery/" + uploadedFile.FileName;
try
{
Image nimg = dload.FindControl("img" + count) as Image;
nimg.ImageUrl = newpath.ToString();
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
}
}
else
{
Page.ClientScript.RegisterStartupScript(GetType(), "msgbox", "alert('Please Select only Image Files!!');", true);
}
}
else
{
Page.ClientScript.RegisterStartupScript(GetType(), "msgbox", "alert('Please Select a File First!!');", true);
}
}
public void createImgPanel()
{
tid = tid + 1;
textid = "txt" + tid;
ta = new TextBox();
img = new Image();
ta.TextMode = TextBoxMode.MultiLine;
dload = new Panel();
updtpanel.Visible = true;
dload.Attributes.Add("class", "dataload");
//dload.Attributes.Add("runat", "server");
dload.ID = "ind" + tid;
img.CssClass = "loadimg";
img.ID = "img" + tid;
//img.Attributes.Add("runat", "server");
ta.Attributes.Add("class", "txtdes");
ta.ID = textid;
//ta.Attributes.Add("runat", "server");
dload.Controls.Add(img);
dload.Controls.Add(ta);
updtpanel.Controls.Add(dload);
}
protected void btnsave_Click(object sender, EventArgs e)
{
if (Page.IsPostBack)
{
Panel pv = (this.Form.FindControl("mainbk").FindControl("updtpanel")) as Panel;
foreach (Control cd in pv.Controls)
{
cnt1 = cnt1 + 1;
TextBox txt = cd.FindControl("ind" + cnt1).FindControl("txt" + cnt1) as TextBox;****This is where I am getting the above said error****
Image img = cd.FindControl("ind" + cnt1).FindControl("img" + cnt1) as Image;
string str = "";
str = txt.Text;
string iurl = "";
iurl = img.ImageUrl;
id += 1;
string Insert = "Insert into slider (slid,slurl,slalt) values (@id,@IMAGE_PATH,@alter)";
SqlCommand cmd = new SqlCommand(Insert, con);
cmd.Parameters.AddWithValue("@IMAGE_PATH", iurl);
cmd.Parameters.AddWithValue("@id", id);
cmd.Parameters.AddWithValue("@alter", str);
try
{
con.Open();
cmd.ExecuteNonQuery();
con.Close();
}
catch (Exception e1)
{
Response.Write(e1.Message);
}
}
updtpanel.Visible = false;
}
}
*我在上面代码的最后一部分遇到错误,即保存按钮点击事件。对于"文本框查找"控件,我遇到错误。第一个图像将被成功保存,但对于其他图像,即使它们存在于设计中,它也无法找到控制*
我只想知道我是否在保存点击事件中犯了任何错误,或者整个编码本身是否有任何错误
编辑
因此,这是在运行时呈现控件后的HTML源代码:
<div id="mainbk" class="transbox" style="position:absolute; top:0px; left:0px; width: 100%; height: 100%;">
<input type="file" multiple="multiple" name="UploadImages" id="UploadImages" style="width:500px;background-color:white; position:absolute; font-family:'Palatino Linotype'; font-size:medium; top: 4px; left: 350px; right: 251px;">
<input type="submit" name="uploadedFile" value="Upload" id="uploadedFile" style="position:absolute; font-family:'Palatino Linotype'; font-size:medium; top: 4px; left: 870px; width: 112px; height: 29px;">
<div id="updtpanel" class="transbox" style="width:100%;height:100%;left:0px;top:0px;position:absolute">
<input type="submit" name="btnsave" value="Save" id="btnsave" style="background-color:Yellow;font-weight:bold;">
<div class="head">Write Description</div><div id="ind1" class="dataload">
<img id="img1" class="loadimg" runat="server" src="../Images/Gallery/God%201.jpg">
<textarea name="txt1" rows="2" cols="20" id="txt1" class="txtdes"></textarea>
</div><div id="ind2" class="dataload">
<img id="img2" class="loadimg" runat="server" src="../Images/Gallery/God%202.jpg">
<textarea name="txt2" rows="2" cols="20" id="txt2" class="txtdes"></textarea>
</div><div id="ind3" class="dataload">
<img id="img3" class="loadimg" runat="server" src="../Images/Gallery/God%203.jpg">
<textarea name="txt3" rows="2" cols="20" id="txt3" class="txtdes"></textarea>
</div>
</div>
</div>
已编辑
K我只是更深入地了解了我遇到的异常。。。据说。。
'((System.Web.UI.HtmlControls.HtmlContainerControl)(dv)).InerHtml'引发了类型为"System.Web.HttpException"的异常
这到底意味着什么。。它还说控制不是字面意义上的。。那是什么意思。。为什么找不到我附加的控件请帮帮我。。
在PreRender事件中添加控件,至少从PageLoad访问它们。
在HTML源代码被渲染到浏览器后,您还可以包括它吗?如果cd.FindControl("ind" + cnt1)
在第一种情况下返回null怎么办?
cd.FindControl("ind" + cnt1).FindControl("txt" + cnt1) as TextBox