I have been looking for a way to get the HTML out of a WPF WebBrowser control. The two best options I have found are to bind a customer attached property to the property in the application or to build a new control from the WebBrowser control. Considering my level of knowledge and the fact that (as of now I really only need this one time) I chose the first. I even considered breaking MVVM style and using code-behind but I decided not to give up in the binding.
I found several examples on creating the attached property, I finally chose this one, from here Here:
namespace CumminsInvoiceTool.HelperClasses
{
public static class WebBrowserExtentions
{
public static readonly DependencyProperty DocumentProperty =
DependencyProperty.RegisterAttached("Document", typeof(string), typeof(WebBrowserExtentions), new UIPropertyMetadata(null, DocumentPropertyChanged));
public static string GetDocument(DependencyObject element)
{
return (string)element.GetValue(DocumentProperty);
}
public static void SetDocument(DependencyObject element, string value)
{
element.SetValue(DocumentProperty, value);
}
public static void DocumentPropertyChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
{
WebBrowser browser = target as WebBrowser;
if (browser != null)
{
string document = e.NewValue as string;
browser.NavigateToString(document);
}
}
}
}
I also added the following to the xaml for the WebBrowser control (I have tried both with and without the "Path=" in the xaml:
<WebBrowser local:WebBrowserExtentions.Document="{Binding Path=PageCode}" Source="https://www.cummins-distributors.com/"/>
My View has a tab control one tab has the WebBrowser control and another tab has a textbox. When I click the get code the viewModel runs a function to set property bound to the textbox to the string the attached property of the WebBrowser is bound to. Below is the code of my ViewModel.
namespace CumminsInvoiceTool.ViewModels
{
class ShellViewModel : Screen
{
private string _browserContent;
public string BrowserContent
{
get { return _browserContent; }
set {
_browserContent = value;
NotifyOfPropertyChange(() => BrowserContent);
}
}
private string _pageCode;
public string PageCode
{
get { return _pageCode; }
set {
_pageCode = value;
NotifyOfPropertyChange(() => PageCode);
}
}
public void StartProgressCommand()
{
}
public void GetContent()
{
if (!string.IsNullOrEmpty(PageCode))
{
BrowserContent = PageCode;
}
else
{
MessageBox.Show("There is no cintent to show", "No content Error", MessageBoxButton.OK);
}
}
}
}
The application compiles and runs but when I click "Get Code" I am getting the messagebox for "PageCode" is empty.
When I set a break point at the beginning of the function for the button, the PageCode string is showing "null".
Is this an issue because I am using Caliburn.Micro or am I missing something else?
------- EDIT for comments ----------
The button calls GetContent() in the "ShellViewModel" code above. I know the button is bound and working because the app is showing the custom messagebox I have set up to let me know when "pageCode" is null or empty.
The textbox looks like:
<TextBox x:Name="BrowserContent"/>
Related
I have a User Control(next UC) with label. I need on button click change a UC label content. On UC codebehind i create DependencyProperty and methods to change a label.
public string InfoLabel
{
get
{
return (string)this.GetValue(InfoLabelProperty);
}
set
{
this.SetValue(InfoLabelProperty, value);
}
}
private static void InfoLabelChangeCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
UserControl1 uc = d as UserControl1;
uc.CInfoLabel.Content = uc.InfoLabel;
}
public static readonly DependencyProperty InfoLabelProperty = DependencyProperty.Register("InfoLabel", typeof(string), typeof(UserControl1), new PropertyMetadata("", new PropertyChangedCallback(InfoLabelChangeCallback)));
On ShellView i got Binding on control and button.
<c:UserControl1 InfoLabel="{Binding InfoLabel1}" />
<Button x:Name="ChangeUserControllButton"/>
On ShellViewModel I have Binding InfoLabel1.
private string infoLabel= "something";
public string InfoLabel1
{
get
{
return infoLabel;
}
set
{
infoLabel = value;
}
}
public void ChangeUserControllButton()
{
InfoLabel1 = "Hello world";
}
The problem is When a UC is initialize, then it`s work. I mean label from UC will have content "something", but when I Click on button, content not changing to "Hello world". How to make it right?
View model needs to implement INotifyPropertyChanged so as to be able to notify UI that it should refresh/update because the bound model has changed. I believe that there is already a base class that provides that functionality.
Reference Caliburn.Micro.PropertyChangedBase
Update ShellViewModel to be derived from PropertyChangedBase and then in property call one of the available methods that would allow your view model to notify UI of property changed.
public class ShellViewModel : PropertyChangedBase {
private string infoLabel= "something";
public string InfoLabel1 {
get {
return infoLabel;
}
set {
infoLabel = value;
NotifyOfPropertyChange();
//Or
//Set(ref infoLabel, value);
}
}
public void ChangeUserControllButton() {
InfoLabel1 = "Hello world";
}
}
Read more at https://caliburnmicro.com/ to get examples of how to use the framework.
I'm making a custom control textbox that has a Cue (filler text) and CueColor (filler text color) properties. I created an Enter and Leave event inside the textbox to regulate the Cue. When I tried applying it, however, it crashes my IDE (Visual Studio 2015, if this helps).
I've read a few posts with similar questions:
Winforms user controls custom events
Although I'm not quite sure if my problem has the same solution. How do I make it work? Here is my code for clarity:
class CueTextBox : TextBox
{
public string Cue
{
get { return Cue; }
set { Cue = value;}
}
public Color CueColor
{
get { return CueColor; }
set { CueColor = value; }
}
private void CueTextBox_Enter(object sender, EventArgs e)
{
TextBox t = sender as TextBox;
if (t.ForeColor == this.CueColor)
{
t.Text = "";
t.ForeColor = this.ForeColor;
}
}
private void CueTextBox_Leave(object sender, EventArgs e)
{
TextBox t = sender as TextBox;
if (t.Text.Trim().Length == 0)
{
t.Text = Cue;
t.ForeColor = this.CueColor;
}
}
}
The only thing that I see in your code is that the property definitions are recursively calling themselves and this will cause a stack overflow when adding the control to the design surface.
public string Cue
{
get { return Cue; }
set { Cue = value;}
}
Either define a backing field or use auto-implemented properties.
private string cue = String.Empty;
public string Cue
{
get { return cue; }
set { cue = value; }
}
or
public string Cue { get; set; }
Your question implied adding event handlers caused the issue. This can be a problem for custom controls at times. There is the Control.DesignMode property that is meant to allow conditional execution of code. However, it does not operate in the constructor. You need to do a bit of a hack to determine if the IDE is active.
This property can be used for development in Visual Studio as an alternative to DesignMode.
private bool InDesignMode
{
get
{
return (System.ComponentModel.LicenseManager.UsageMode == System.ComponentModel.LicenseUsageMode.Designtime) ||
base.DesignMode ||
(System.Diagnostics.Process.GetCurrentProcess().ProcessName == "devenv");
}
}
In solution development of custom controls is an exercise in self abuse. You are better of to go to Project Properties->Debug Tab and set the "Start Action" to "Start External Program" with "devenv.exe" as the program. This will start a new instance of VS when you "run" the debugger. When you add a control to the design surface of the new VS instance, you can debug your control's code. Break points will be hit and exceptions displayed.
I created a custom class called BrowseButton which extends Button. This button is fairly simple; when clicked it pops up a file chooser dialog. I created it as its own special class because I wanted to be able to re-use it quickly and easily in my applications. After the user successfully selects a file, I also want it to populate a TextBox control on the same page with the full file path.
Here's what my (C#) code looks like for the button:
using System;
using System.Windows;
using System.Windows.Controls;
using Microsoft.Win32;
namespace MyProject.Extensions
{
public partial class BrowseButton : Button
{
public static readonly DependencyProperty DefaultExtDependency = DependencyProperty.Register("DefaultExt", typeof(string), typeof(BrowseButton));
public static readonly DependencyProperty FilterDependency = DependencyProperty.Register("Filter", typeof(string), typeof(BrowseButton));
public static readonly DependencyProperty TextBoxDependency = DependencyProperty.Register("TextBox", typeof(TextBox), typeof(BrowseButton));
public string DefaultExt
{
get
{
return (string)GetValue(DefaultExtDependency);
}
set
{
SetValue(DefaultExtDependency, value);
}
}
public string Filter
{
get
{
return (string)GetValue(FilterDependency);
}
set
{
SetValue(FilterDependency, value);
}
}
public TextBox TextBox
{
get
{
return (TextBox)GetValue(TextBoxDependency);
}
set
{
SetValue(TextBoxDependency, value);
}
}
public BrowseButton()
{
InitializeComponent();
}
public event EventHandler<string> FileSelected;
public void Connect(int connectionId, object target)
{
}
private void BrowseButton_OnClick(object sender, RoutedEventArgs e)
{
var dialog = new OpenFileDialog
{
DefaultExt = DefaultExt,
Filter = Filter
};
var result = dialog.ShowDialog();
if (result == true)
{
if (FileSelected != null)
{
FileSelected(this, dialog.FileName);
}
if (TextBox != null)
{
TextBox.Text = dialog.FileName;
}
}
}
}
}
So far, so good. I can quickly create a "Browse..." button in XAML. However, I can't get the TextBoxDependency working in the way that I was hoping it would work.
What I want to be able to do is something like this (XAML):
<TextBox x:Name="MyTextBox" />
<extensions:BrowseButton TextBox="MyTextBox" />
However, when I drop that in it says this:
The TypeConverter for "TextBox" does not support converting from a string.
Is there some way to accomplish what I want to do here? To effectively reference another XAML element inside of a XAML element, without having to leave XAML to do it?
Use a binding:
<TextBox x:Name="MyTextBox" />
<extensions:BrowseButton TextBox="{Binding ElementName=MyTextBox}" />
I am using WPF (C#) for the first time and this I've encountered my first "real" design choice. I have a main window and when the user enters some data and presses the "plot" Button, a new window will come up showing a graph.
This graph window I am defining myself with a combination of xaml and the code-behind file. The issue is that 2 parameters this window has is the x axis title and the y axis title. So, these should be "parameters" to making this window.
I am confused by this because I'm using MVVM and I have a "ViewModel" for the window called GraphWindowPresenter and a "View" for the class called GraphWindowView.
At first, I tried to have an xAxis property and a yAxis property in my GraphWindowPresenter but that will not work since I need to "bind" to these values upon construction of the GraphWindowView. Additionally, this approach would require that my GraphWindowPresenter take an xAxis parameter and a yAxis parameter which is problamatic as well since I just create an instance of the class in the xaml of GraphWindowView.
I'm thinking of a possible soltuion that I can just have my GraphWindowView take the xAxis and yAxis parameters but doesn't this violate MVVM? I would rather not do that.
Note: This is similar to this post MVVM: Binding a ViewModel which takes constructor args to a UserControl. But in my scenario it is tricky since I have a parent window and a pop up child window.
Question: What is the best approach to this design issue? What are the "best practices" regarding this scenario?
Possible Answer:
Is this the correct use of dependency properties that you described? Is this a "clean" solution?
private void doGraph()
{
if (log == null) // if a log is not loaded
{
MessageBoxResult mbr = MessageBox.Show("A log file must be " +
"loaded before plotting.",
"Warning",
MessageBoxButton.OK,
MessageBoxImage.Exclamation);
return;
}
// NOW MUST PRESENT GRAPH WINDOW
GraphWindowView gwv = new GraphWindowView();
gwv.xAxis = X_AXIS_VALUE:
gwv.yAxis = Y_AXIS_VALUE;
gwv.Show();
}
And in my GraphWindowView class I have the code:
public partial class GraphWindowView : Window
{
// Using a DependencyProperty as the backing store for yAxis.
public static readonly DependencyProperty yAxisProperty =
DependencyProperty.Register("yAxis", typeof(string), typeof(GraphWindowView));
// Using a DependencyProperty as the backing store for xAxis.
public static readonly DependencyProperty xAxisProperty =
DependencyProperty.Register("xAxis", typeof(string), typeof(GraphWindowView));
public string xAxis
{
get { return (string)GetValue(xAxisProperty); }
set { SetValue(xAxisProperty, value); }
}
public string yAxis
{
get { return (string)GetValue(yAxisProperty); }
set { SetValue(yAxisProperty, value); }
}
public GraphWindowView()
{
InitializeComponent();
}
}
You can you userSetting properties
One my application have same scenario in that i have mainWindow that accept HostAddress,Port value and it will use another window when i click connect so i am using userSetting properties. I am also using MVVM pattern check code snippet below
XAML:
<TextBox Width="120" Canvas.Left="132" Canvas.Top="16" Text="{Binding Path=Server,Mode=TwoWay}"/>
<TextBox Width="120" Canvas.Left="132" Canvas.Top="42" Text="{Binding Path=DisplayPort,Mode=TwoWay}"/>
<TextBox Width="120" Canvas.Left="132" Canvas.Top="69" Text="{Binding Path=CtrlPort,Mode=TwoWay}"/>
<Button Content="Launch" Name="btnLaunch" Command="{Binding Path=appSetting}" Canvas.Left="132" Canvas.Top="100" Width="120" Height="51" Click="btnLaunch_Click" />
VIEWMODE:
public class SettingsViewModel : ViewModelBase
{
private Settings _settings { get; set; }
public SettingsViewModel()
{
appSetting = new RelayCommand(this.AppSettingsCommand);
_settings = ApplicationTest.Properties.Settings.Default;
}
private string _server = Settings.Default.Server;
public string Server
{
get { return this._server; }
set
{
if (this._server != value)
{
this._server = value;
OnPropertyChanged("Server");
}
}
}
private string _displayPort = Settings.Default.DisplayPort;
public string DisplayPort
{
get { return this._displayPort; }
set
{
if (this._displayPort != value)
{
this._displayPort = value;
OnPropertyChanged("DisplayPort");
}
}
}
private string _ctrlPort = Settings.Default.CtrlPort;
public string CtrlPort
{
get { return this._ctrlPort; }
set
{
if (this._ctrlPort != value)
{
this._ctrlPort = value;
OnPropertyChanged("DisplayPort");
}
}
}
public RelayCommand appSetting
{
get;
set;
}
private void AppSettingsCommand()
{
this._settings.Server = this.Server;
this._settings.DisplayPort = this.DisplayPort;
this._settings.CtrlPort = this.CtrlPort;
this._settings.Save();
}
I am using the Model-View-ViewModel architecture in a WPF application I am building, and I would like a specific ViewModel to actually be reactive to the size of the view (not a normal use-case of the MVVM approach, I know).
Essentially, I have a ScrollViewer object and I want the viewmodel to observe the width and height of the scrollviewer and then be able to do things accordingly depending on what that width and height are.
I'd like to do something like this:
<ScrollViewer ViewportWidth="{Binding Path=MyViewportWidth, Mode=OneWayToSource}" ViewportHeight="{Binding Path=MyViewportHeight, Mode=OneWayToSource}" />
But of course this is impossible to do because "ViewportWidth" and "ViewportHeight" cannot be "bound to" (a.k.a. act as binding targets) because they are read-only dependency properties (even though I am not writing to them at all in this binding since it is OneWayToSource).
Anyone know of a good method to be able to do something like this?
You could try running something OnLoaded or OnResizeChanged that updates the viewmodel
private void ScrollViewer_Loaded(object sender, RoutedEventArgs e)
{
ScrollViewer sv = sender as ScrollViewer;
ViewModel vm = sv.DataContext as ViewModel;
vm.ScrollViewerHeight = sv.ViewportHeight;
vm.ScrollViewerWidth = sv.ViewportWidth;
}
Ok, this is a really old question, but I thought I'd share for posterity, since I've solved this one myself. The best solution I've found is to create a user control that derives from the ScrollView class and implements the properties you want - which are of course linked to the non-bindable properties of the base class.
You can use the OnPropertyChanged function to monitor those properties and keep the values in sync.
Here's the full code-behind of my custom usercontrol called DynamicScrollViewer. Notice that I have four bindable dependency properties called DynamicHorizontalOffset, DynamicVerticalOffset, DynamicViewportWidth, and DynamicViewportHeight.
The two offset properties allow both read and write control of the offset, while the viewport properties are essentially read-only.
I had to use this class when creating a complex animation editor control in which various components (labels at the left, nodes in the middle, timeline at top) needed to scroll synchronously, but only in limited aspects, and were all bound to common external scrollbars. Think of locking a section of rows in spreadsheet, and you get the idea.
using System.Windows;
using System.Windows.Controls;
namespace CustomControls
{
public partial class DynamicScrollViewer : ScrollViewer
{
public DynamicScrollViewer()
{
InitializeComponent();
}
public double DynamicHorizontalOffset
{
get { return (double)GetValue(DynamicHorizontalOffsetProperty); }
set { SetValue(DynamicHorizontalOffsetProperty, value); }
}
public static readonly DependencyProperty DynamicHorizontalOffsetProperty =
DependencyProperty.Register("DynamicHorizontalOffset", typeof(double), typeof(DynamicScrollViewer));
public double DynamicVerticalOffset
{
get { return (double)GetValue(DynamicVerticalOffsetProperty); }
set { SetValue(DynamicVerticalOffsetProperty, value); }
}
public static readonly DependencyProperty DynamicVerticalOffsetProperty =
DependencyProperty.Register("DynamicVerticalOffset", typeof(double), typeof(DynamicScrollViewer));
public double DynamicViewportWidth
{
get { return (double)GetValue(DynamicViewportWidthProperty); }
set { SetValue(DynamicViewportWidthProperty, value); }
}
public static readonly DependencyProperty DynamicViewportWidthProperty =
DependencyProperty.Register("DynamicViewportWidth", typeof(double), typeof(DynamicScrollViewer));
public double DynamicViewportHeight
{
get { return (double)GetValue(DynamicViewportHeightProperty); }
set { SetValue(DynamicViewportHeightProperty, value); }
}
public static readonly DependencyProperty DynamicViewportHeightProperty =
DependencyProperty.Register("DynamicViewportHeight", typeof(double), typeof(DynamicScrollViewer));
protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
{
base.OnPropertyChanged(e);
if (e.Property == DynamicVerticalOffsetProperty)
{
if (ScrollInfo != null)
ScrollInfo.SetVerticalOffset(DynamicVerticalOffset);
}
else if (e.Property == DynamicHorizontalOffsetProperty)
{
if (ScrollInfo != null)
ScrollInfo.SetHorizontalOffset(DynamicHorizontalOffset);
}
else if (e.Property == HorizontalOffsetProperty)
{
DynamicHorizontalOffset = (double)e.NewValue;
}
else if (e.Property == VerticalOffsetProperty)
{
DynamicVerticalOffset = (double)e.NewValue;
}
else if (e.Property == ViewportWidthProperty)
{
DynamicViewportWidth = (double)e.NewValue;
}
else if (e.Property == ViewportHeightProperty)
{
DynamicViewportHeight = (double)e.NewValue;
}
}
}
}