I have a WPF System.Windows.Controls.WebBrowser control in a Window. A user can enter information and hit a submit button into the webpage displayed by the WebBrowser. After the page posts back it uses a scripting object to communicate with my application. I need to make sure that once the submit button has been pressed, the form doesn't close or otherwise stop waiting for the web page to post back. It would be great if I could check the state of the WebBrowser or its document via a property like "IsLoading" and cancel any actions if it is loading. I didn't see anything like that so I was thinking of setting a flag on the Navigating event and unsetting it on the Navigated or LoadCompleted event, but there is a case where I click a link on the web page (tied to javascript, it doesn't go to a new page) where Navigating is fired, but Navigated and LoadCompleted never fire. Is there a way to determine the state of the browser on demand?
As per MSDN if the Navigating event gets invoked then the Navigated Event will also get fired unless you explicitly Cancel the navigation. I tried the below code-snippet it seems to be working fine. (i.e) whenever the Navigated event is getting fired following Navigating event.
void Window1_Loaded(object sender, RoutedEventArgs e)
{
browser = new WebBrowser();
browser.Navigate(new Uri("http://www.google.com"));
browser.Navigating += new NavigatingCancelEventHandler(browser_Navigating);
browser.Navigated += new NavigatedEventHandler(browser_Navigated);
}
void browser_Navigating(object sender, NavigatingCancelEventArgs e)
{
Console.WriteLine("Loading Webpage !!");
}
void browser_Navigated(object sender, NavigationEventArgs e)
{
Console.WriteLine("Webpage Loaded !!");
}
If this is not what you are looking for, then provide the webpage URL in which you are facing the issue.
No, there does not appear to be a way to query the WPF browser's status on demand. I settled on my original idea of setting my own flag in the Navigating event handler and unsetting it in the Navigated event handler. It was not working reliably for me because there was a script that canceled navigation (javascript:void(0)).
Related
I was creating a browser window for my WPF application. During the visibility change I am loading the URL, but when I change the URL content and load the same URL it is showing previous content first, then after a blinking it shows the updated data.
void OnWindowVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if (!IsBrowserInitialized) return;
if (window.Visibility == Visibility.Visible)
{
Dispatcher.BeginInvoke(new Action(() =>
{
LoadNewUrl();
window.Activate();
}));
}
else
{
Dispatcher.BeginInvoke(new Action(() =>
{
ChromeBrowser.LoadHtml("<html><body><h1></h1></body></html>");
}));
}
}
Suppose the URL contains "ABCD" as data. First time it is showing the correct content. After the update the data becomes "ABCDEF". Now on Load() the initial content is showing then the updated content.
Is there anything else I need to do for avoiding this issue?
I'm not sure what LoadHtml() does, it's not a part of the native CEF API. In any case the blank page is about:blank, i.e. ChromeBrowser.Load("about:blank").
Are you aware of stopping all activities in the hidden browser? It seems to be the issue - you load an empty page and hide the window, the browser stops any activities, then you activate the window and still see an old content, then an empty page causes "blinking", and finally a new content is shown.
You should catch change visibility request, cancel it, load about:blank and hide the window on load completion. The client handler has appropriate events.
I have this strange issue I am facing currently.
I have created an WPF application based on WPF page navigation. I have few button and depending on the button click the the user is navigated to respective WPF page.
In these WPF pages I have Tab controls and have used selectionchanged event handler to perform some task.
Now to the issue,
When I try to go a particular page, the selectionchanged event is also executed even before the page is loaded completely, I have tried to use the windows.loaded (based on the answer provided to my previous question - here) - I have no luck.
[I am using WPF Navigation framework]
Somehow the selectionchanged event is executing twice.
How do I stop this from happening?
I think you should check SelectionChange.AddedItems and SelectionChange.RemovedItems to find the difference between these to firings. I guess that when you select a page, SelectionChange.RemovedItems==0 while when you click on a tabItem to select it, SelectionChange.RemovedItems==1. if so just write:
if (SelectionChange.RemovedItems==0)
return;
Edit1: Please see the first comment.
Edit 2
void tablcontrol_SelectionChange(object sender, SelectionChangedEventArgs e)
{
if (e.RemovedItems.Count == 0)
{
// I guess this is the event that happens when a page is selected
// in this case just a TabItem is added to the selection
// and nothing is removed, so do nothing
return;
}
// if you are here, it means that this is another selection changed event
// so Perform those tasks that you mentioned in your question
}
In Microsoft's Toolkit DataForm
User is trying to add a new item in Toolkit Dataform by clicking Add icon. In the middle if he selects any other menu tab, then he is going to lose all the entered info.
I want to show promt to User to Save When Leaving a Page. Like Warning user before leaving page with unsaved changes.
After some research I found the solution.
Theere is a Method called OnNavigatingFrom in Silverlight page. that methods is Called just before a page is no longer the active page in a frame.
So you can add any alert or confirm message in that methods.
protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
if (DataForm.IsEditMode)
{
System.Windows.Browser.HtmlPage.Window.Alert("Please Save or Cancel changes before switching the page");
e.Cancel = true;
}
base.OnNavigatingFrom(e);
}
that will be called when you want to move to other page from current page edit or add mode.
I have a Win form application (VS 2010 / C#) and I'm trying to figure out how to refresh pages without a refresh button. Currently I can refresh a page (basically to reset the data bindings) with a refresh button containing code something like this (this.refresh() does not seem to work for some reason):
this.Hide();
AccountSettings AS = new AccountSettings();
AS.ShowDialog();
An example I have is a page with numerous settings including data grids with CellClick events. When I click a cell I can make changes to a database. I hit close to go back to the Settings page but the only way for me to see the changes are to refresh() the page via the button.
So the short of it is, is there any way to refresh a form page from another form page?
For instance, when I click the Save button or close the child window.
Maybe pass the original form as an argument to the second form:
Form2 frm2 = new Form2(this);
And in Form2:
Form1 frm1;
public Form2(Form1 frm1)
{
InitializeComponent();
this.frm1 = frm1;
}
And then have in Form2:
frm1.Update();
Refresh on winform controls repaints the control itself. I find it useful to create a method that just loads my controls with the proper data, and then call it as necessary. (Including Form load)
private void ResetData()
{
//code to update settings
}
If you are showing the form that is closing as a dialog also you can take advantage of that, and check the status of the dialog instead of just opening it.
Form2 dlg = new Form2();
if (dlg.ShowDialog == System.Windows.Forms.DialogResult.OK) {
//code that updates your data
ResetData();
}
If its not a dialog there are a few things you could do and how your application works would make one method better than others. Here is just one example.
If your changes are something you don't need access to data from the other window to update you can handle the closed event of the form you create.
Create a class level variable to hold the form that is opened, so that you can also remove the event handlers you create:
private Form2 frm;
To create an instance of the form, and add the close event handler:
frm = new Form2();
frm.FormClosed += OnForm2Closed;
The event handler method:
private void OnForm2Closed(object sender, FormClosedEventArgs e)
{
ResetData();
frm.FormClosed -= OnForm2Closed;
}
I have an XBAP Application.
In XBAP Page, if the user presses F5 or CTRL+R then the confirmation message must be shown to the user.
If Yes then the page must be reloded.
If No then the current page must remain as it is.
Can any one help how to do this.
You could call on NavigationMode of Navigating event parameter, like code below shows,
Application.Current.Navigating += new NavigatingCancelEventHandler(Current_Navigating);
void Current_Navigating(object sender, NavigatingCancelEventArgs e)
{
if (e.NavigationMode == NavigationMode.Refresh)
{
//put your logic here
}
}
If user trigger refresh operation either by F5 or Ctrl+R combination keys, you could catch this event and handle it.