I have a question and I can not find the right terms to do a reasoned search and solve the question.
Let's see, when I'm creating a page, at some point I need to create a WebUserControl and defer something like state = "true" (like the text of the lables) inside the html tag so that as soon as the page loads , Whether or not that control is subsequently edited in code.
<MyControls:Teste Id="aaa" runat="server" state="false"/>
The test control code is as follows: (The HTML page of this control is blank, it only has the header)
public partial class WebUserControls_WUC_Tect : System.Web.UI.UserControl
{
private static bool state ;
public bool State
{
get { return state ; }
set { state = value; }
}
protected void Page_Load(object sender, EventArgs e)
{
}
}
Problem:
Whenever the page returns to the server and is reloaded, the state variable is always set to false or true depending on the initial state I passed, what I intended was for this variable to be loaded only once at the beginning of the page and then Could only be changed by codebeind.
I am grateful for your suggestions.
greetings
Patrick Veiga
You need to use the ViewState to store the property value to keep the persistent value saved.
public partial class WebUserControls_WUC_Tect : System.Web.UI.UserControl
{
private static bool state ;
public bool State
{
get
{
if (ViewState["MyState"] == null)
{
ViewState["MyState"] = false;
}
return (bool)ViewState["MyState"];
}
set
{
ViewState["MyState"] = value;
}
}
protected void Page_Load(object sender, EventArgs e)
{
}
}
Related
Suppose i have created a WPF form having one text box. i am calling that form inside another wpf window's gridpanel and after entering value inside the textbox, i am clicking on submit button. After button click, i need to get that value and save it in string form inside my current class. My logic is something like this.
For getting the from inside my current window:-
void SelectedClick(object sender, RoutedPropertyChangedEventArgs<object> e)
{
selectedItem.ContextMenu = VcontextMenu;
VcontextMenu.Items.Add(VmenuItem1);
VmenuItem1.Click += AddValidation;
details();
}
void AddValidation(object sender, RoutedEventArgs e)
{
ValidationForm obj = new ValidationForm();
ProcessGrid.Content = obj.VForm;
}
Now i want to store the value of my textbox inside a string. For that i have used following code:-
public void details()
{
ValidationForm obj = new ValidationForm();
string str = obj.s.ToString();
}
My ValidationForm Code:-
public partial class ValidationForm : UserControl
{
public string s { get; set; }
public ValidationForm()
{
InitializeComponent();
}
public void XSave_Click(object sender, RoutedEventArgs e)
{
s = TextValidationName.Text;
}
}
but instead of opening the form, the control is going to obj.s.ToString() and showing error as "Object reference not set to an instance of an object." Please help. Thanks.
The issue is caused since the string s in your ValidationForm class is not assigned. It is probably caused since the XSave_Click() method is not being called.
Ensure that you properly assign the value to s before you try to get value from it.
I am trying to create a custom component. The component should by dynamically initialized in code behind. The component presents a custom Window containing other components, like datefields, dropdown fields etc. I derived my class from Ext.Net.Window and added simple DateField. The date should than be used by a button click on the server (Date should not be passed over DirectMethod parameter). When I add this component to mark-up it works perfectly. But when I add the window in code behind, the value of the datefield is not set after the server call.
I am creating the window in the life cycle in OnInit event by "Controls.Add(mywindow)". It would be great if anybody could give me a hint. Here my window code (onExecuteButtonClick just calls the direct method and hides the window):
public sealed class WindowFilterComponent:Window
{
private const string Script = "MyProject.JavaScript.src.WindowFilterComponent.js";
public override string InstanceOf
{
get
{
return "MyProject.Filter.WindowFilterComponent";
}
}
public override string XType
{
get
{
return "windowfiltercomponent";
}
}
private Button _btnExecute;
private Button _btnCancel;
private DateField _dateField;
protected override void OnInit(EventArgs e)
{
AutoHeight = true;
_btnExecute = new Button("Execute Export");
_btnExecute.Listeners.Click.Handler = string.Format("#{{{0}}}.onExecuteButtonClick()", ID);
_btnCancel = new Button("Cancel");
_btnCancel.Listeners.Click.Handler = string.Format("#{{{0}}}.onCancelButtonClick()", ID);
Buttons.Add(_btnExecute);
Buttons.Add(_btnCancel);
_dateField = new DateField();
Items.Add(_dateField);
base.OnInit(e);
}
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
if (ExtNet.IsAjaxRequest || Page.IsCallback) return;
ResourceManager.GetInstance().AddDirectMethodControl(this);
}
[DirectMethod(ShowMask = true)]
public void ExecuteClick()
{
var date = _dateField.SelectedValue;
}
}
Now the useage in my page in the OnInit event:
protected override void OnInit(EventArgs e)
{
var myWindow = new WindowFilterComponent()
{
Hidden = false,
Width = 500
};
myWindow.ID = myWindow.ID + "MyComponent";
Controls.Add(myWindow);
base.OnInit(e);
}
I think the Window is rendered outside of the Form.
Please replace
Controls.Add(myWindow);
with
Form.Controls.Add(myWindow);
Also I would recommend to set up explicit IDs for the submittable fields (the DateField in your case) to ensure that the id key from POST data will match the control's ID on the server.
I want to ask you, what do you think, what is the best approach to get from second page to first page? I use something like this.(MVVM)
Second page:
public partial class AddProfilePageView : PhoneApplicationPage
{
public AddProfilePageView()
{
InitializeComponent();
DataContext = new AddProfileViewModel();
}
public AddProfileViewModel ViewModel { get { return DataContext as AddProfileViewModel; } }}
First page:
public partial class ProfilesPageView : PhoneApplicationPage
{
public ProfilesPageView()
{
InitializeComponent();
DataContext = new ProfilesViewModel();
}
public ProfilesViewModel ViewModel
{
get { return DataContext as ProfilesViewModel; }
}}
AddProfileViewModel() class has properties, that are binded to controls in xaml. From this page I need to get data to first page ProfilesPageView.
My solution is:
protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)
{
var content = e.Content as ProfilesPageView;
if (content != null && ViewModel.IsOk)
{
content.ViewModel.ProfilesList.Add(ViewModel.ProfileRecord);
}
}
So what do you think? Is it good solution how obtain data?
Thanks
In reality here you're not trying to get data from one page to another.
On the second/detail page you're adding a new item and then when you return to the first/main page you want it to update the displayed data to show the new item.
I'd assume that AddProfileViewModel and ProfilesViewModel are both persisting to disk/IsolatedStorage so you could just refresh the main/list/first page when returning to it.
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
// ...
if (e.NavigationMode == NavigationMode.Back)
{
(this.DataContext as ProfilesViewModel).Refresh();
}
}
This question is for an ASP.NET guru. Its driving me nuts.
I have inherited an ASP.NET Web Forms application. This application uses a complex
structure of nested user controls. While complex, it does seem necessary in this case.
Regardless, I have a page that uses a single UserControl. We will call this UserControl
root control. This UserControl is defined as follows:
widget.ascx
<%# Control Language="C#" AutoEventWireup="true" CodeFile="widget.ascx.cs" Inherits="resources_userControls_widget" %>
<div>
<asp:Panel ID="bodyPanel" runat="server" />
</div>
widget.ascx.cs
public partial class resources_userControls_widget : System.Web.UI.UserControl
{
private string source = string.Empty;
public string Source
{
get { return source; }
set { source = value; }
}
private string parameter1 = string.Empty;
public string Parameter1
{
get { return parameter1; }
set { parameter1 = value; }
}
private DataTable records = new DataTable();
public DataTable Records
{
get { return records; }
set { records = value; }
}
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
UserControl userControl = LoadControl(source) as UserControl;
if (parameter1.Length > 0)
userControl.Attributes.Add("parameter1", parameter1);
bodyPanel.Controls.Add(userControl);
}
private void InsertUserControl(string filename)
{
}
}
In my application, I am using widget.ascx in the following way:
page.aspx
<uc:Widget ID="myWidget" runat="server" Source="/userControls/widgets/info.ascx" />
page.aspx.cs
protected void Page_Load(object sender, EventArgs e)
{
DataTable table = GetData();
myWidget.Records = table;
}
Please notice how info.ascx is set as the UserControl we want to load in this case. This approach is necessary in this case. I've removed the extraneous code that justifies it to focus on the problem. Regardless, in info.ascx.cs I have the following:
info.ascx.cs
protected void Page_Load(object sender, EventArgs e)
{
// Here's the problem
// this.Parent.Parent is a widget.ascx instance.
// However, I cannot access the Widget class. I want to be able to do this
// Widget widget = (Widget)(this.Parent.Parent);
// DataTable table = widget.Records;
}
I really need to get the value of the "Records" property from the Parent user control. Unfortunately, I can't seem to access the Widget class from my code-behind. Are there some rules about UserControl visibility at compile time that I'm not aware of? How do I access the Widget class from the code-behind of info.ascx.cs?
Thank you!
Firstly you need to create an interface and implement it to the Widget user control class.
For instance,
public interface IRecord
{
DataTable Records {get;set;}
}
public partial class resources_userControls_widget : System.Web.UI.UserControl, IRecord
{
...
}
And in code behind of Info.ascx.cs,
protected void Page_Load(object sender, EventArgs e)
{
// Here's the problem
// this.Parent.Parent is a widget.ascx instance.
// However, I cannot access the Widget class. I want to be able to do this
// Widget widget = (Widget)(this.Parent.Parent);
// DataTable table = widget.Records;
IRecord record=this.Parent.Parent;
DataTable table = widget.Records;
}
In your case, maybe better to use some server object's like ViewState or Session. Fill it within DataTable on your page and get it in Page_load event handler on info.ascx user control.
I'm developing an aplication for Windows 7, and I need to block a page.. my solutions are not register that frame or clear all the frames in back.
Guessing that you mean you have a page on the Back-stack that you want to remove --
In the new Mango SDK, there's a Method you can try NavigationService.RemoveBackEntry
However it might be easier to just use a boolean and check in OnNavigatedTo:
At page where you need to go back > 1 pages:
in App.xaml.cs:
public static bool IsBackwardNavigation = false;
public static string PageContext = string.Empty;
Page2.xaml.cs :
public void YourFunction()
{
App.PageContext = "MainPage";
App.IsBackwardNavigation = true;
if (NavigationService.CanGoBack)
NavigationService.GoBack();
}
And in each page's OnNavigatedTo:
Page1.xaml.cs:
string Page1 = "Page1";
protected override void OnNavigatedTo(object sender, NavigationEventArgs e)
{
if (App.IsBackwardNavigation)
{
if (!Page1.Equals(App.NavigationContext)
{
//since this page's name is not the correct page, the page will go back again.
if (NavigationService.CanGoBack)
NavigationService.GoBack();
}
else
{
//this is the page we're trying to get to
App.IsBackwardNavigation = false;
App.NavigationContext = string.Empty;
}
}
}
}