How to declare public variable from protected method in asp net? - asp.net

Question

I have database with images in folder on my server. To display this images I'am using DataList control. ItemTemplate include also a LinkButton
<asp:LinkButton ID="wybierzZdjecieBtn" OnClick="choosePhotoButton_Click" CommandArgument='<%#Eval("PhotoLinkAddress")%>' CssClass="wybierzZdjecieButton" runat="server">Choose photo</asp:LinkButton>
To receiving Value from LinkButton CommandArgument i'am using this method:
protected void choosePhotoButton_Click(object sender, EventArgs e)
{
LinkButton button = (LinkButton)(sender);
string photoLinkAddressVar = button.CommandArgument.ToString();
Response.Write(PhotoLinkAddressVar);
}
This works fine, no problems. But this is not what I want achieve. My intentions is send this variable "PhotoLinkAddressVar" to this method:
protected void addNewNews_Click(object sender, EventArgs e)
{
string trescStatus = "czeka";
string autor = Session["userName"].ToString();
DateTime data = DateTime.Now;
string dataFormat = "";
dataFormat = data.ToString("dd/MM/yyyy H:mm");
string CS = ConfigurationManager.ConnectionStrings["wiadomosciConnection"].ConnectionString;
using (SqlConnection con = new SqlConnection(CS))
{
con.Open();
string dodaj = "Insert into News (TytulNews, TrescNews, Autor, Data, Kategoria, Dotyczy, PhotoLinkAddress, Status) values (#TytulNews, #TrescNews, #Autor, #Data, #Kategoria, #Dotyczy, #PhotoLinkAddress, #Status)";
SqlCommand com = new SqlCommand(dodaj, con);
com.Parameters.AddWithValue("#TytulNews", tytulNewsTextBox.Text);
com.Parameters.AddWithValue("#TrescNews", trescTextBox.Text);
com.Parameters.AddWithValue("#Autor", autor);
com.Parameters.AddWithValue("#Data", dataFormat);
com.Parameters.AddWithValue("#Kategoria", kategoria.SelectedValue.ToString());
com.Parameters.AddWithValue("#Dotyczy", dotyczy.SelectedValue.ToString());
com.Parameters.AddWithValue("#PhotoLinkAddress", photoLinkAddressVar);
com.Parameters.AddWithValue("#Status", trescStatus);
com.ExecuteNonQuery();
}
}
User have to choose photo before press "Add News", because if He doesn't do that, he will receive error message. I dont know, how do that. I Was trying declare some kind public variable before PageLoad and do something like this:
protected void choosePhotoButtonButton_Click(object sender, EventArgs e)
{
LinkButton button = (LinkButton)(sender);
photoLinkAddressVar = button.CommandArgument.ToString();
}
but that method won't declare the variable. Do You have any idea, how can I achieve that ?.

Answer 1

You could use also the ViewState.
protected void choosePhotoButton_Click(object sender, EventArgs e)
{
LinkButton button = (LinkButton)(sender);
string photoLinkAddressVar = button.CommandArgument.ToString();
View["photoLinkAddressVar"]=photoLinkAddressVar;
Response.Write(PhotoLinkAddressVar);
}
Then in the addNewNews_Click method, you coukld retrieve this value with the following way:
com.Parameters.AddWithValue("#PhotoLinkAddress", ViewState["photoLinkAddressVar"]);
For further documantation about ViewState please look here.