I have two tabs, each of which is initialized by a separate context. Both open synchronously, but on the screen at this moment, of course, only one is visible. That tab, which is NOT on the screen, will not start loading the address until it is clearly clicked with the mouse and shown. Are there any ways to make it load in the background?
Thank.
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I have a WPF RichTextBox in my application that sits in Grid. It gets updated every second or two as it displays logs (though sometimes there are no logs for up to a minute depending on the load).
The grid is not always visible, as it sits in its own tab. If the user is on another tab, the logger is not visible.
My problem is that I want the RichTextBox to scroll to the end every time a new paragraph is added. It seemed simple as there is a 'ScrollToEnd' method on the RichTextBox control and so I call that method every time text is added to the control.
The problem is that that method only works if the control is visible, if the user is on another tab, the RichTextBox will not scroll to the end and it looks weird when you click on the tab with the logger and after a couple of seconds or longer it scrolls to the bottom when it should already be at the bottom.
Is there a way around this annoying "feature" of the control? I would like to ALWAYS have the RichTextBox be at the bottom unless the user is manually taking control of the scroll bar.
Thanks!
By default, the TabControl actually doesn't change its contents visibility, it removes them from the view completely when you change tabs and then "re-attachs" them when you navigate back to the previous tab.
That's why the Visibility change doesn't get fired. Instead, you should handle the Loaded event, which should get fired right before the view is re-rendered.
Is there a reason you cannot simply call ScrollToEnd in response to the text box becoming visible? That seems like the simplest approach. Did you try it and run into an issue?
Edit: If you are using a TabControl, each TabItem has an IsSelected property you can bind to from the ItemContainerStyle. You could probably scroll your text box in response to the tab becoming selected.
As a separate note: if you are planning to make a custom control for this, here are some things to consider.
I wrote an auto-scrolling version of a FlowDocumentScrollViewer. (I never needed a RichTextBox specifically, but they display similar content.) I can tell you that there are a lot of things to account for, such as knowing when and when not to auto-scroll based on what the user is currently doing.
For example:
If the user takes over the scrolling themselves via the scrollbar or mousewheel, you don't want the control to fight with them.
If they start selecting text, you don't want to scroll it away from them mid selection.
If they scroll to the bottom, you probably want it to start auto-scrolling again.
Also, determining what the user is doing to begin with can sometimes be a complex process on its own.
The project is based on wp 7.5.
I have a grid, and when the user swipe it, a textbox will reveal and the keyboard will show.
The function is ok, but there is a little bug, when the system keyboard show, it will cover over the textbox, so the user can't see the stuff they have entered.
how to solve it?
It would be best to position such a textbox so that it would not be obscured when the keyboard is shown. This is typically done by placing it at (or near) the top of the page.
Depending on how you've structured your XAML the default behaviour of the phone should scroll the content so that it is not obscured by the keyboard. Without being able to see you code I couldn't say why this isn't happening.
Alternatively you could but the page content inside a ScrollViewer and manually scroll it so that the TextBox is visible when it has focus.
I am working on a WPF application where I need smooth animations and transitions between pages.
On startup, I instantiate all my controls, with Visibility : Collapsed, and when I go from a control to another, I animate the two controls and change the visibility.
My problem is on a control with several images : the first time I display it, we don't see the animation (probably because it loads the images in the same time). When I load it a second time, there's no problem.
Is there a way to preload this control in order to always have smooth animations ?
In the codebehind you can have an event handler OnLoaded() for when the your control is loaded for the first time. Here you can load in the images or even have them start as Visible so they are loaded and at the end of the handler, have them go back to being Collapsed.
First of all, I do not feel completely educated on how to navigate between multiple "pages" of a window.
For example, I have a Window called MainWindow. Inside of this, I have a header and a footer. In the middle is a panel which contains content.
This panel will originally contain content A. Upon clicking something in A, I want to remove A from view and show a new panel with content B. However, I want B to be shown in the same window (i.e., not hide the window and open a new one). Is hiding/showing these panels the correct way to go about it?
If using the panel switching mechanism is the correct way, then I am worried about resource management. If I set panel A to not be visible, and panel B to be visible, will I still have resources from both panels loaded? If I have a large number of panels to switch between, I would not want to load content for all of them, but rather the active one.
How would I go about making sure that I am correctly handling resources and memory between these different views?
If I have the completely wrong idea about how to switch views within a single window, please let me know.
Thanks.
Instead of toggling visibility off and on, you should put a contentControl and switch it's contents to different UserControls.
That way there's no reference to the UserControl that's offscreen, and you can handle memory issues better.
One alternative is to just use a single ContentPresenter, and put your individual "panels" in there, but only one at a time.
Instead of flipping visibility, you could use Data Binding to change the bound content within the ContentPresenter. This would only leave a single "view" in place at a time, preventing the neeed for "a large number" of panels to be loaded.
On C# winforms project, I have a small table, a filter box, an Add button and a Done button grouped together, and they all fit together within 250x250 pixels. I only need to show these elements to the user when they press a button. I figured this could be done using a pop up modal screen or by making room on the main screen until the user presses the Done button.
I know a disadvantage to modal screens is that they can cause problems for users when/if they lose track of the modal screen and then they think the program's not responding.
The disadvantage I see for using a dynamic main screen is that the reshaping interferes with the overall layout. But maybe I could find a way to overcome that problem.
I'm new to all of this, so I wanted to ask opinions here. Thanks.
Put them all on a panel (or, even better, a custom control), style it to look nice, and then only show the panel on button click.
If you put them in a groupBox or FlowLayout panel possibly in the corner of the main screen and then set the visibility or even enabled on the entire control when they can or can't press the buttons works well.
disable until time they can edit.
groubB.enabled = true;
or
groubB.Visible = true;
When the user clicks the button, could you disable all of the controls in the main form and then place the panel in the center of the main form, on top of the other controls? Maybe make the panel a little larger with some decoration around it for emphasis. Then, when the user clicks 'done,' dismiss the panel and re-enable all of the controls in the main form.