On my aspx page has a button. I want to change its property dynamically.
For example:
A button which ID is Button1 and I want to change its property Visible to false.
On code behind have three variables hidefield = "Button1", property = "Visible" and value = false.
Is it possible to set the property Visible using the variables?
aspx:
<asp:Button ID="Button1" runat="server" Text="Button1" />
code behind:
protected void Page_Load(object sender, EventArgs e)
{
string hidefield = "Button1";
string property = "Visible";
bool value = false;
if (!IsPostBack)
{
Control myControl1 = FindControl(hidefield);
if (myControl1 != null)
{
myControl1.property = value; // <- I know this statement has error. Is there any way to set the property like this?
}
}
}
Using reflection, based on Set object property using reflection
using System.Reflection;
protected void Page_Load(object sender, EventArgs e)
{
string hidefield = "Button1";
string property = "Visible";
bool value = false;
if (!IsPostBack)
{
Control myControl1 = FindControl(hidefield);
if (myControl1 != null)
{
myControl.GetType().InvokeMember(hidefield ,
BindingFlags.Instance | BindingFlags.Public | BindingFlags.SetProperty,
Type.DefaultBinder, myControl, value);
}
}
}
It's pretty messy and not very human readable so therefore could have maintainablility issues.
how about this:
Button myControl1 = FindControl(hidefield) as Button;
if (myControl1 != null)
{
myControl1.Visible= value;
}
protected void Page_Load(object sender, EventArgs e)
{
string hidefield = "Button1";
string property = "Visible";
bool value = false;
if (!IsPostBack)
{
/* Use below two lines if you are using Master Page else you wouldnot be able to access your control */
ContentPlaceHolder MainContent = Page.Master.FindControl("MainContent") as ContentPlaceHolder;
Control myControl1 = MainContent.FindControl(hidefield);
if (myControl1 != null)
{
myControl1.GetType().GetProperty(property).SetValue(myControl1,value,null);
}
}
}
Related
After several searches on the Internet finally decided to drop a question.
At runtime I want the following to happen.
If you push a button a textbox will be added to the controls and a custom validator must be attached to the textbox and fire.
It does not fire. Why?
Here is my code
Thank you for looking into this.
public partial class WebUserControl1 : System.Web.UI.UserControl
{
CustomValidator rv2 = new CustomValidator();
protected void Page_Init(object sender, EventArgs e)
{
if (!IsPostBack)
{
rv2.ID = "rev2";
rv2.ErrorMessage = "Not numeric input";
rv2.ClientValidationFunction = "";
rv2.ServerValidate += new ServerValidateEventHandler(GetalValidator);
Controls.Add(rv2);
}
}
protected void ButtonClick(object sender, EventArgs args)
{
TextBox tb1 = new TextBox();
tb1.ID = "tb2";
tb1.Visible = true;
tb1.Width = 30;
this.Controls.Add(tb1);`enter code here`
rv2.EnableClientScript = false;
rv2.ControlToValidate = "tb2";
}
private bool IsNumber(string someText)
{
int number;
bool result = Int32.TryParse(someText, out number);
return result;
}
protected void GetalValidator(object source, ServerValidateEventArgs args)
{
args.IsValid = IsNumber(args.Value);
}
}
here is part of code thorugh which you can add validation on your dynamically created control.
TextBox tb1 = new TextBox();
tb1.ID = "tb2";
tb1.Visible = true;
tb1.Width = 30;
RequiredFieldValidator regfv = new RequiredFieldValidator();
regfv.ID = "regfv";
regfv.ControlToValidate = tb1.ID;
regfv.ErrorMessage = "My Error";
this.Controls.Add(tb1);
this.Controls.Add(regfv);
I am using visual studio 2010 and crystal report 13.0
The report viewer displays the first page properly. But the next page button is not working. If i click on next page button then it shows loading message and stays there only.None of the report viewer controls are working.
please help me out
I found the solution.
Manually add the Page_Init() event and wire it up in the InitializeCompnent() with
this.Init += new System.EventHandler(this.Page_Init).
Move the contents of Page_Load to Page_Init().
Add if (!IsPostBack) condition in PageInIt.
protected void Page_Init(object sender, EventArgs e)
{
if (!IsPostBack)
{
ReportDocument crystalReportDocument = new ReportDocumment();
crystalReportDocument.SetDataSource(DataTableHere);
_reportViewer.ReportSource = crystalReportDocument;
Session["ReportDocument"] = crystalReportDocument;
}
else
{
ReportDocument doc = (ReportDocument)Session["ReportDocument"];
_reportViewer.ReportSource = doc;
}
}
Instead of manually identifying the moment to bind, you could use the CrystalReportViewer AutoDataBind property in combination with the DataBinding event.
Autobind definition:
// Summary:
// Boolean. Gets or sets whether automatic data binding to a report source is
// used. If the value is set to True, the DataBind() method is called after
// OnInit() or Page_Init().
[Category("Data")]
[DefaultValue(false)]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
public bool AutoDataBind { get; set; }
You could use this property in the following manner:
In the ASPX:
<CR:CrystalReportViewer ID="_reportViewer" runat="server" AutoDataBind="true" OnDataBinding="_reportViewer_DataBinding" />
And in the ASPX.CS:
protected void _reportViewer_DataBinding(object sender, EventArgs e)
{
if (!IsPostBack)
{
ReportDocument crystalReportDocument = new ReportDocumment();
crystalReportDocument.SetDataSource(DataTableHere);
_reportViewer.ReportSource = crystalReportDocument;
Session["ReportDocument"] = crystalReportDocument;
}
else
{
ReportDocument doc = (ReportDocument)Session["ReportDocument"];
_reportViewer.ReportSource = doc;
}
}
Done! Shift your Page load Event to Page Init Event.
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
int pageIndex =((CrystalDecisions.Shared.PageRequestContext)
CrystalReportViewer1.RequestContext).PageNumber;
//Bind Report with filter and datasource
string ControID = GetPostBackControlName(this);
//get and check Crystal Report Navigation button event after Bind Report
if (ControID == null)
{
((CrystalDecisions.Shared.PageRequestContext)
CrystalReportViewer1.RequestContext).PageNumber = pageIndex;
}
}
}
public string GetPostBackControlName(Page Page)
{
Control control = null;
string ctrlname = Page.Request.Params["__EVENTTARGET"];
if (ctrlname != null && ctrlname != String.Empty)
{
control = Page.FindControl(ctrlname);
}
else
{
string ctrlStr = String.Empty;
Control c = null;
foreach (string ctl in Page.Request.Form)
{
if (ctl.EndsWith(".x") || ctl.EndsWith(".y"))
{
ctrlStr = ctl.Substring(0, ctl.Length - 2);
c = Page.FindControl(ctrlStr);
}
else
{
c = Page.FindControl(ctl);
}
if (c is System.Web.UI.WebControls.Button ||
c is System.Web.UI.WebControls.ImageButton)
{
control = c;
break;
}
}
}
if (control == null)
{
return null;
}
else
{
return control.ID;
}
}
I have a ListView in an ASP.NET web application. When a user clicks the edit button, I want textfields to pop up that are dependent on certain values of the item. However, I can't seem to find any controls inside of my ListView1_ItemEditing() function.
I have read the Microsoft documentation and various help threads on the internet, but their suggestions do not appear to work for me. This is generally what I see:
ListViewItem item = ProductsListView.Items[e.NewEditIndex];
Label dateLabel = (Label)item.FindControl("DiscontinuedDateLabel");
For the sake of simplicity I just want to be able to select a label in ListView1_ItemEditing(). This is the code in ListView1_ItemEditing():
protected void ListView1_ItemEditing(Object sender, ListViewEditEventArgs e)
{
DataBind(); //not sure if this does anything
ListViewItem item = ListView1.Items[e.NewEditIndex];
Label debugLabel = (Label)item.FindControl("label_editing");
debugLabel.Text = "Works";
}
Here is the ASP
<EditItemTemplate>
<asp:Label ID="label_editing" runat="server" Text="hello world"></asp:Label>
</EditItemTemplate>
When debugging, item and debugLabel are both NULL.
UPDATE: I resolved this issue by moving my logic to ItemDataBound and then checking if my tr (containing textboxes) was in that particular data item. Code below:
protected void ListView1_ItemDataBound(object sender, ListViewItemEventArgs e)
{
if (e.Item.ItemType == ListViewItemType.DataItem)
{
Control tr_verizon = e.Item.FindControl("tr_verizonEdit");
Control tr_att = e.Item.FindControl("tr_attEdit");
if (tr_verizon != null)
{
//Control tb_meid = e.Item.FindControl("TextBox_Meid");
Label lbl_carrierId = (Label)e.Item.FindControl("lbl_carrierId");
if (lbl_carrierId == null)
{
Message.Text = "lbl_carrierId is null!";
}
else if (lbl_carrierId.Text.Equals(""))
{
Message.Text = "lbl_carrierId is empty!";
}
else
{
string recordId = lbl_carrierId.Text;
if (tr_verizon != null && tr_att != null)
{
if (lbl_carrierId.Text.Equals("1"))
{
tr_verizon.Visible = false;
tr_att.Visible = true;
}
else
{
tr_verizon.Visible = true;
tr_att.Visible = false;
}
}
}
}
}
}
The ItemEditing event is raised when an item's Edit button is clicked, but before the ListView item is put in edit mode. Therefore controls in EditItemTemplate are not available at this time.
More Info and example
You should do the DataBind() first, like this:
ListView1.EditIndex = e.NewEditIndex;
ListView1_BindData(); // a function that get the DataSource and then ListView1.DataBind()
// Now find the control as you did before
Have you tried casting the sender object instead of trying to access your ListViewItem by index?
protected void ListView1_ItemEditing(Object sender, ListViewEditEventArgs e)
{
var item = sender as ListViewItem;
var debugLabel = item.FindControl("label_editing") as Label;
debugLabel.Text = "Works";
}
So I have a listbox on my page and some textfields. Through the textfields I can add an item to my listbox (click the button, it adds it to a private List<string> which is then set as a ViewState and the list is databound again).
My listbox is also in an updatepanel which gets triggered on the button's Click event.
Problem: My Viewstate remains null on a postback so it gets reset each time.
Some code:
private List<IngredientData> _ingredientsList;
protected void Page_Load(object sender, EventArgs e)
{
// prepare ingredient lists
_ingredientsList = new List<IngredientData>();
if (Page.IsPostBack)
{
if (ViewState["IngredientsList"] != null)
{
_ingredientsList = (List<IngredientData>) ViewState["IngredientsList"];
}
}
lstIngredients.DataSource = _ingredientsList;
lstIngredients.DataTextField = "Text";
lstIngredients.DataValueField = "Name";
lstIngredients.DataBind();
}
protected void btnAddIngredient_Click(object sender, EventArgs e)
{
_ingredientsList.Add(new IngredientData { Name = txtIngredientName.Text, Quantity = txtUnitQuantity.Text, Unit = lstUnits.SelectedValue });
ViewState["IngredienstList"] = _ingredientsList;
lstIngredients.DataSource = _ingredientsList;
lstIngredients.DataBind();
}
Any idea how I can fix this? Am I doing something wrong?
btnAddIngredient_Click is adding to "IngredienstList" not "IngredientsList" (note the spelling).
You can avoid this kind of typo by using a constant:
private const string IngredientsListViewStateKey = "IngredientsList";
then referring to it like this:
ViewState[IngredientsListViewStateKey] = _ingredientsList;
namespace Dynamic_Controls.Dropdowndynamic
{
public partial class DropdowndynamicUserControl : UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
if (ControlCount != 0)
{
Recreatecontrols();
}
}
private void Recreatecontrols()
{
// createtextboxes(ControlCount);
createtextboxes(2);
}
protected void createtextboxes(int ControlCount)
{
DynPanel.Visible = true;
for (int i = 0; i <= ControlCount; i++)
{
TextBox tb = new TextBox();
tb.Width = 150;
tb.Height = 18;
tb.TextMode = TextBoxMode.SingleLine;
tb.ID = "TextBoxID" + this.DynPanel.Controls.Count;
tb.Text = "EnterTitle" + this.DynPanel.Controls.Count;
tb.Load+=new EventHandler(tb_Load);
tb.Visible = true;
tb.EnableViewState = true;
DynPanel.Controls.Add(tb);
DynPanel.Controls.Add(new LiteralControl("<br/>"));
}
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
Int32 newControlCount = Int32.Parse(DropDownList1.SelectedValue);
//createtextboxes(newControlCount);
//ControlCount+=newControlCount;
createtextboxes(2);
}
protected void Button1_Click(object sender, EventArgs e)
{
readtextboxes();
}
public void readtextboxes()
{
string x = string.Empty;
for (int a = 0; a < DynPanel.Controls.Count; a++)
{
foreach (Control ctrl in DynPanel.Controls)
{
if (ctrl is TextBox)
{
x = ((TextBox)ctrl).Text;
}
x+=x+("\n");
}
Result.Text = x;
}
}
private Int32 ControlCount
{
get
{
if (ViewState["ControlCount"] == null)
{
ViewState["ControlCount"] = 0;
}
return (Int32)ViewState["ControlCount"];
}
set
{
// ViewState["ControlCount"] = value;
ViewState["ControlCount"] = 2;
}
}
private void tb_Load(object sender, EventArgs e)
{
LblInfo.Text = ((TextBox)sender).ID + "entered";
}
}
}
Are you adding these controls dynamically in Page_Load (by, I'm assuming, calling your AddRequiredControl() method)? If so, is it wrapped in a conditional which checks for IsPostBack? The likely culprit is that you're destructively re-populating the page with controls before you get to the button click handler, so all the controls would be present but empty (as in an initial load of the page).
Also, just a note, if you're storing each control in _txt in your loop, why not refer to that variable instead of re-casting on each line. The code in your loop seems to be doing a lot of work for little return.
You need to recreate any dynamically created controls on or before Page_Load or they won't contain postback data.
I'm not entirely clear what happens on DropdownList changed - are you trying to preserve anything that has been entered already based on the textboxes previously generated?
In any event (no pun intended) you need to recreate exactly the same textboxes in or before Page_Load that were there present on the postback, or there won't be data.
A typical way to do this is save something in ViewState that your code can use to figure out what to recreate - e.g. the previous value of the DropDownList. Override LoadViewState and call the creation code there in order to capture the needed value, create the textboxes, then in the DropDownList change event, remove any controls that may have been created in LoadViewState (after of course dealing with their data) and recreate them based on the new value.
edit - i can't figure out how your code works now, you have AddRequiredControl with parameters but you call it with none. Let's assume you have a function AddRequiredControls that creates all textboxes for a given DropDownList1 value, and has this signature:
void AddRequiredControls(int index)
Let's also assume you have a PlaceHolder called ControlsPlaceholder that will contain the textboxes. Here's some pseudocode:
override void LoadViewState(..) {
base.LoadViewState(..);
if (ViewState["oldDropDownIndex"]!=null) {
AddRequiredControls((int)ViewState["oldDropDownIndex"]);
}
}
override OnLoad(EventArgs e)
{
// process data from textboxes
}
void DropDownList1_SelectedIndexChanged(..) {
ControlsPlaceholder.Controls.Clear();
AddRequiredControls(DropDownList1.SelectedIndex);
ViewState["oldDropDownIndex"]=DropDownList1.SelectedIndex;
}