Having to use pre render is causing me problems.. It would be great if I did not need it.. The problem is I have the list in a user control and when I goto the next 'page' I databind.. but then the datapager prerenders.. which also does a batabind.. so it runs twice..
If I remove the prerender .. then clicking next 'page' does nothing..
Any idea?
protected void Page_Load(object sender, EventArgs e)
{
GetSearchResults();
}
//protected void dpMembers_PreRender(object sender, EventArgs e)
//{
// GetSearchResults();
//}
public void GetSearchResults()
{
List<Person> listPerson = new List<Person>();
string strServer = "localhost";
string strAppPath = Server.MapPath("/");
PersonBusiness pb = new PersonBusiness(new PersonRepository());
listPerson = pb.GetAllPersons(strServer, strAppPath);
lvPersons.DataSource = listPerson;
lvPersons.DataBind();
}
Modify your Page load to
protected void Page_Load(object sender, EventArgs e)
{
if(!Page.IsPostBack)
{
GetSearchResults();
}
}
your prerender seems ok.
Related
I have some validation code in my WebForm page. When a user clicks on a button and does a postback.
Page_Load event gets processed then the Button1_Click event gets processed.
I can't figure out a way to stop the Button1_Click event from processing if the validation fails on Page_Load.
Is a trick to do this?
Thanks
4 variations shown below.
public partial class _Default : System.Web.UI.Page
{
private bool MyPageIsValid { get; set; }
protected void Page_Load(object sender, EventArgs e)
{
if (Page.IsPostBack)
{
bool valid = false; /* some routine here */
MyPageIsValid = valid;
}
}
protected void Button1_Click(object sender, EventArgs e)
{
if (this.MyPageIsValid)
{
this.TextBox1.Text = DateTime.Now.ToLongTimeString();
}
}
protected void Button2_Click(object sender, EventArgs e)
{
if (!this.MyPageIsValid) {return;}
this.TextBox1.Text = DateTime.Now.ToLongTimeString();
}
protected void Button3_Click(object sender, EventArgs e)
{
if (this.Page.IsValid)
{
this.TextBox1.Text = DateTime.Now.ToLongTimeString();
}
}
protected void Button4_Click(object sender, EventArgs e)
{
if (!this.Page.IsValid) {return;}
this.TextBox1.Text = DateTime.Now.ToLongTimeString();
}
}
I think it should be better to check validation conditions exactly in the Button1_Click method like this:
if (!this.IsValid()) { return; }
Also if you still want to check that conditions in Page_Load method just add simple 'bool isValid' flag to your page's class and then check it in Button1_Click:
if (!this.isValid) { return; }
protected void Page_Init(object sender, EventArgs e)
{ }
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DropDownList1.DataSource = SomeObject.GetData();
DropDownList1.DataBind();
} }
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
var selvalue = DropDownList1.SelectedValue;
DoSomething(selvalue);
}
Please some body help me to make works properly this code if ViewState turned off.
If you turn the viewstate off, then you need to rebind the data on every trip to the server and before the page initializes.
Example of a dropdownlist without viewstate
I have a drop down box that populates textbox values based on its value. It fires when it is changed but on pageload it doesnt fire. How do I get it to fire on page load?
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
TextBox3.Text = DropDownList1.SelectedValue;
TextBox12.Text = DropDownList1.SelectedValue;
TextBox21.Text = DropDownList1.SelectedValue;
//etc
Tim Schmelter's comment is right on the money.
// Wire up to the page load event
protected void Page_Load(object sender, System.EventArgs e)
{
updateTextBoxes();
}
// Wire up to the select index-changed event
protected void DropDownList1_SelectIndexChanged( object sender, EventArgs e )
{
updateTextBoxes();
}
// your workhorse method
protected void updateTextBoxes()
{
TextBox3.Text = DropDownList1.SelectedValue;
TextBox12.Text = DropDownList1.SelectedValue;
TextBox21.Text = DropDownList1.SelectedValue;
// etc.
}
It won't be called automatically at page load, you have to call it "manually":
void Page_Load(object sender, System.EventArgs e) {
// ....
DropDownList1_SelectedIndexChanged(DropDownList1, e);
}
SelectedIndexChanged fires in response to a user-driven change. Move the assignment logic to another method and call it manually from Page_Load and also from your event handler.
I have this:
protected void Page_Load(object sender, EventArgs e)
{
nome_Txt.Text = Profile.dados_pessoais.nome;
}
protected void save_Click(object sender, EventArgs e)
{
Profile.dados_pessoais.nome = nome_Txt.Text;
}
If Profile.dados_pessoais.nome is empty, nome_txt.Text is empty too. When I change nome_Txt.Text to teste for example, when I click on the button nome_Txt.Text is empty.
What am I doing wrong?
The Page_Load event run before the button click event so you always assign the text box to empty value.
To solve this, don't populate the textbox when you are in a Postback:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
nome_Txt.Text = Profile.dados_pessoais.nome;
}
}
As also stated in a comment, you probably have to save the profile after changing it otherwise it won't be saved when you next load the page:
protected void save_Click(object sender, EventArgs e)
{
Profile.dados_pessoais.nome = nome_Txt.Text;
Profile.Save()
}
I want to preserve the dynamically created control when postback occurs .
protected void Page_Load(object sender, EventArgs e)
{
}
private void CreateTable()
{
HtmlTableRow objHtmlTblRow = new HtmlTableRow();
HtmlTableCell objHtmlTableCell = new HtmlTableCell();
objHtmlTableCell.Controls.Add(new TextBox());
objHtmlTblRow.Cells.Add(objHtmlTableCell);
mytable.Rows.Add(objHtmlTblRow);
this.SaveControlState();
// this.Controls.Add(mytable);
}
protected void Button1_Click(object sender, EventArgs e)
{
CreateTable();
}
It can be achieved by calling CreateTable() in Page_Load. Is there any alternative way to preserve the control
Thanks
You can add them to a List when you create them and save your List to Session. On postback (Page_Load) load them from your Session to your Page.
the below code should work
protected void Page_PreInit(object sender, EventArgs e)
{
Control myControl = GetPostBackControl(this.Page);
}
protected override void OnInit(EventArgs e)
{
base.OnInit(e);
CreateTable()
}
public static Control GetPostBackControl(Page thisPage)
{
Control ctrlPostedback = null;
string ctrlName = thisPage.Request.Params.Get("__EVENTTARGET");
if (!String.IsNullOrEmpty(ctrlName))
{
ctrlPostedback = thisPage.FindControl(ctrlName);
}
else
{
foreach (string Item in thisPage.Request.Form)
{
Control c = thisPage.FindControl(Item);
if (((c) is System.Web.UI.WebControls.Button))
{
ctrlPostedback = c;
}
}
}
return ctrlPostedback;
}
The code works from UpdatePanel
Reference:http://www.asp.net/ajax/videos/how-to-dynamically-add-controls-to-a-web-page