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Hi,
I am new to prism framework. So I created a Obervable collection for datagrid. So When i poulated it the view was also affected and it showed whatever the chnge was.
But when i use on a single variable the value is not chnaged in the view. So can you help me to sort out this issue
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The only really remarkable thing about an ObservableCollection is that it implements INotifyCollectionChanged. This interface contains a CollectionChanged event when the number of items in the collection is changed somehow. When WPF sees that an item it is binding to implements this interface, it knows that it can listen to this event.
Okay, so that's the ObservableCollection. Why did I bring it up? Well, that's because the collection changing is taken care of for you by a custom collection. Property changes, on the other hand, aren't handled automatically for you. When you think about it, you can see why this is desirable. Would you really want WPF to be listening for changes on every property you've bound it to, even if those properties are straightforward primitives. Implementing automatic change binding on these would put a tremendous strain on your application because you would potentially be wiring up many items that you don't want to. So, how do you do property change notification? Well, in just the same way you have INotifyCollectionChanged, there's a property change interface that WPF understands called INotifyPropertyChanged. This interface has a PropertyChanged event that you raise to tell WPF that a particular item has changed (by passing the name of the item that changed, or an empty string if you want WPF to refresh all properties).
Now, if you've heard of MVVM, you're probably aware of a concept called a ViewModel. The ViewModel is intended to isolate the View from the Model. It's a common implementation pattern that has a BaseViewModel class that handles the INotifyPropertyChanged (often abbreviated to INPC). So, the base VM would look something like this:
public abstract class BaseViewModel : INotifyPropertyChanged
{
protected void NotifyOfChange(string property)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler == null) return;
handler(this, new PropertyChangedEventArgs(property));
}
public event PropertyChangedEventHandler PropertyChanged;
}So, your derived VM would possibly look something like this:
public class MyViewModel : BaseViewModel
{
private int _onlineCount;
public int OnlineCount
{
get { return _onlineCount; }
set
{
if (_onlineCount == value) return;
_onlnieCount = value;
NotifyOfChange("OnlineCount");
}
}
}
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I ve given like this. Should I inherit the view model class in the xaml.cs file.
The rest above i ve written as such in my project. But still not changing
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Member 10053752 wrote: I ve given like this. Should I inherit the view model class in the xaml.cs file
No.
Without seeing any of your code, it's difficult to see what the issue is.
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if u can give me your mail id i can share my project with you
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I can mail my project t u .. but can u give me ur mail id I can share it
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Hello everyone
In my WPF project I have created a UserControl (this is called Applic.xaml), and within this usercontrol I have placed a nested UserControl (this is called PasswordScreen.xaml). Here is the xaml design code of Applic.xaml usercontrol:
<UserControl xmlns:my2="clr-namespace:iPosCloud.com.iposcloud.uiC_.views"
x:Class="iPosCloud.com.iposcloud.main.Applic"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:my0="clr-namespace:iPosCloud.com.iposcloud.main"
xmlns:Intersoft="http://intersoft.clientui.com/schemas"
xmlns:my1="clr-namespace:Intersoft.Client.UI.Controls;assembly=Intersoft.Client.UI.Controls"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="800" d:DesignWidth="1024" xmlns:my="http://schemas.microsoft.com/surface/2008">
<UserControl.Background>
<ImageBrush ImageSource="/iPosCloud;component/images/HoneyComb.png" Stretch="Fill" TileMode="Tile" Viewport="0,0,46,25" ViewportUnits="Absolute" />
</UserControl.Background>
<UserControl.Resources>
<DropShadowEffect x:Key="DropShadowEffect" ShadowDepth="0.1" Direction="360" BlurRadius="3" Opacity=".5" />
</UserControl.Resources>
<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Name="MainGridApplic">
<Border BorderThickness="2" HorizontalAlignment="Left" Name="border1" VerticalAlignment="Stretch" Margin="4" BorderBrush="{x:Null}">
<Border.BitmapEffect>
<DropShadowBitmapEffect Color="Black" Direction="360" ShadowDepth="10" Opacity=".5" Softness="9" />
</Border.BitmapEffect>
<Intersoft:UXGridPanel Margin="2" Column="1" Row="1" ItemHeight="220" ItemWidth="1190" Name="UXGridPanelLeft">
<Image Name="image1" Source="/iPosCloud;component/images/Logo.png" Width="1000" HorizontalAlignment="Left" />
</Intersoft:UXGridPanel>
</Border>
<Grid Margin="2" HorizontalAlignment="Right">
<my2:PasswordScreen /> "HERE IS THE UserControl THAT I PLACED..."
</Grid>
</Grid>
</UserControl>
In PasswordScreen.xaml usercontrol there is a button (called Login). On the click event when clicked, I want to call another xmal file called SwitchboardView.xaml and display it within the (Applic.xaml usercontrol) but it is not firing nothing and the code behind this button is:
private void btnLogin_Click(object sender, RoutedEventArgs e)
{
SwitchboardView sbv = new SwitchboardView();
Applic ap = new Applic();
ap.MainGridApplic.Children.Add(sbv);
}
Could someone please help me solve this problem with the sample of code (what am I doing wrong...)
Kind regards
Lapeci
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Hi friends,
In Silverlight Web Application, how to display/call an .aspx page in a Frame or any other control when click on a link button?
Please solve my problem ASAP.
Thanks,
Raviteja
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give me introduction about silverlight
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Well, a few years ago, this really great guy called David Silverlight ran community sites for.NET developers. One day, he was invited to spend some time with Bill Gates who said he wanted to name a product after him to thank him for his work in the online.NET community. Fortunately they chose to use his second name.
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heheheheh, some things never change! 
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What? Whistles innocently.
This story may or may not be[^] true. David's a friend of mine, and is a truly great guy.
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Seriously I didn't know this. Thanks Pete 
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Hey guys i need help with a program im working on.
<u>Problem:</u> i have no idea how to get it to work, im still new to developing apps
<u>What needs to be done:</u>
I have two WPF Windows, one is for entering information which will load the entered info into the second window.
And depending on what option selected in the combobox it must load a logo at the top of the second window and its related address below it.
Thanks 
The Layout:
Mainwindow:
<Window x:Class="Other_Stuff.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Entry Form" Height="350" Width="525">
<Grid>
<Grid.RowDefinitions>
<RowDefinition></RowDefinition>
<RowDefinition Height="45"></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="120"></ColumnDefinition>
<ColumnDefinition Width="7*"></ColumnDefinition>
<ColumnDefinition Width="36*"/>
</Grid.ColumnDefinitions>
<Label Grid.Column="0" Grid.Row="0" Content="Client"></Label>
<Label Grid.Column="0" Grid.Row="2" Content="Pharmacy" Margin="-5,5,5,5"></Label>
<Label Grid.Column="0" Grid.Row="3" Content="Script Number"/>
<Button x:Name="Submit" Grid.Column="0" Grid.Row="4" Content="Submit" Click="Button_Click"/>
<TextBox Name="client" Grid.Column="1" Grid.Row="0" Grid.ColumnSpan="2"></TextBox>
<ComboBox Name="PharmacyComboBox" Grid.Column="1" Grid.Row="2" Grid.ColumnSpan="2" Margin="0,0,0,10" >
<ComboBoxItem Content="Dischem" ></ComboBoxItem>
<ComboBoxItem Content="Clicks" MouseLeftButtonUp="ComboBoxItem_MouseLeftButtonUp"></ComboBoxItem>
</ComboBox>
<TextBox Name="Scriptnumber" Grid.Column="1" Grid.Row="3" Grid.ColumnSpan="2" Height="55" VerticalAlignment="Top" Margin="5,0,0,0">
</TextBox>
<Label Content="Medicine" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="0,10,0,0" Grid.Row="1"/>
<ListBox Grid.Column="1" HorizontalAlignment="Left" Height="45" VerticalAlignment="Top" Width="397" Grid.ColumnSpan="2" Grid.Row="1" Name="medlist" Margin="0,5,0,0" Grid.RowSpan="2"/>
<!--<Button Content="Submit" Grid.Column="1" Grid.Row="5" Click="Button_Click" Grid.ColumnSpan="2"></Button>-->
</Grid>
</Window>
ScriptWindow:
Window x:Class="Other_Stuff.Script"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Script" Height="488.06" Width="437.313" Loaded="Window_Loaded">
<Grid>
<Grid.RowDefinitions>
<RowDefinition></RowDefinition>
<RowDefinition Height="45"></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="120"></ColumnDefinition>
<ColumnDefinition Width="7*"></ColumnDefinition>
<ColumnDefinition Width="36*"/>
</Grid.ColumnDefinitions>
<Image Grid.Column="0" Grid.Row="0" Name="LogoImage" Grid.ColumnSpan="3" Margin="0,2,0,43" Grid.RowSpan="2"></Image>
<Label Grid.Row="1" Grid.RowSpan="2" Name="AdresslbLabel" Grid.ColumnSpan="3"/>
<Label Grid.Column="0" Grid.Row="3" Grid.ColumnSpan="3" Name="ScripTextBox"></Label>
<DataGrid Grid.Column="0" Grid.Row="4" Grid.ColumnSpan="3"/>
<TextBox Grid.Column="0" Grid.Row="4" Grid.ColumnSpan="3" Name="RelatedTextBox"/>
<Image Grid.Column="0" Grid.Row="5" Grid.ColumnSpan="3" Grid.RowSpan="2" Name="AdverTextBox"/>
<Button Content="Button" HorizontalAlignment="Left" Margin="10,10,0,0" Grid.Row="7" VerticalAlignment="Top" Width="100" Height="39" Click="Button_Click"/>
</Grid>
</Window>
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You are treating this like a winforms application, STOP. Do some reading on MVVM and data binding if you wish to continue using WPF or actually use winforms.
Never underestimate the power of human stupidity
RAH
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I got a combo box in wpf form I set the ItemSource to the collection of Dictionary of (Pet Type) and just display the Value and hid the Key
public void BindComboBoxes()
{
this.cboTypes.ItemsSource = new BindingSource(CommonMgr.GetPetTypesDropDown(false), null);
this.cboTypes.DisplayMemberPath = "Value";
this.cboTypes.SelectedValuePath = "Key";
}
Then whenever I type to encode a new Breed Object, and type a text in the cboTypes of something that doesn't exist in its items(not in the db), my program will ask if the end user wants to add that new PetType in the db, if yes, then it will do so.
Then i update the cboTypes using the BindComboBoxes method again, set the cboTypes.Text into the new item and assign the Key to the designated field, but the problem is, it says, it was null. it worked fine in the windows form though. Here's my code:
public Breed GetPageEntity()
{
Breed setEntity = new Breed();
bool doesExist = false;
setEntity.Id = DefaultValue.GetInt(this.txtId.Text);
setEntity.BreedName = DefaultValue.GetString(this.txtName.Text);
try
{
setEntity.PetTypeId = DefaultValue.GetInt(this.cboTypes.SelectedValue.ToString());
}
catch (Exception)
{
var addAnother = MessageBox.Show(String.Format("{0}: This type is not in the database. \nAdd {0} to the database?",
this.cboTypes.Text), "Pet Type Cannot Be Found", MessageBoxButtons.OKCancel);
if (addAnother == System.Windows.Forms.DialogResult.OK)
{
petTypeMgr.Entity = this.PetTypeAdder(cboTypes.Text);
string temp = this.cboTypes.Text;
petTypeMgr.Insert((petTypeMgr.Entity), fUser.Entity.Id, ref doesExist);
BindComboBoxes();
cboTypes.Text = temp;
setEntity.PetTypeId = DefaultValue.GetInt(this.cboTypes.SelectedValue);
}
}
setEntity.Description = DefaultValue.GetString(this.txtDescription.Text);
setEntity.SortOrder = DefaultValue.GetInt(txtSortOrder.Text);
setEntity.StatusId = true;
return setEntity;
}
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Mhister Pamakwas wrote: set the cboTypes.Text into the new item and assign the Key to the designated field
I don't recognise the binding method but your combo does not have a selected record, you do not set the mode to TwoWay and you should not be setting the text but putting the value into the selected record and letting the binding update the UI.
Never underestimate the power of human stupidity
RAH
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If is it Possible RichTextBox Document Property Support Binding as FlowDocument.
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Google[^] has plenty of suggestions:
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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Hello everyone
In my WPF project I have created a UserControl (this is called Applic.xaml), and within this usercontrol I have placed another UserControl (this is called PasswordScreen.xaml). Here is the xaml design code:
<UserControl xmlns:my2="clr-namespace:iPosCloud.com.iposcloud.uiC_.views"
x:Class="iPosCloud.com.iposcloud.main.Applic"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:my0="clr-namespace:iPosCloud.com.iposcloud.main"
xmlns:Intersoft="http://intersoft.clientui.com/schemas"
xmlns:my1="clr-namespace:Intersoft.Client.UI.Controls;assembly=Intersoft.Client.UI.Controls"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="800" d:DesignWidth="1024" xmlns:my="http://schemas.microsoft.com/surface/2008">
<UserControl.Background>
<ImageBrush ImageSource="/iPosCloud;component/images/HoneyComb.png" Stretch="Fill" TileMode="Tile" Viewport="0,0,46,25" ViewportUnits="Absolute" />
</UserControl.Background>
<UserControl.Resources>
<DropShadowEffect x:Key="DropShadowEffect" ShadowDepth="0.1" Direction="360" BlurRadius="3" Opacity=".5" />
</UserControl.Resources>
<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Name="MainGridApplic">
<Border BorderThickness="2" HorizontalAlignment="Left" Name="border1" VerticalAlignment="Stretch" Margin="4" BorderBrush="{x:Null}">
<Border.BitmapEffect>
<DropShadowBitmapEffect Color="Black" Direction="360" ShadowDepth="10" Opacity=".5" Softness="9" />
</Border.BitmapEffect>
<Intersoft:UXGridPanel Margin="2" Column="1" Row="1" ItemHeight="220" ItemWidth="1190" Name="UXGridPanelLeft">
<Image Name="image1" Source="/iPosCloud;component/images/Logo.png" Width="1000" HorizontalAlignment="Left" />
</Intersoft:UXGridPanel>
</Border>
<Grid Margin="2" HorizontalAlignment="Right">
<my2:PasswordScreen /> "HERE IS THE UserControl THAT I PLACED..."
</Grid>
</Grid>
</UserControl>
In PasswordScreen.xaml there is a button (called Login). On click event when clicked I want to call another xmal file called SwitchboardView.xaml but not firing nothing and the code behind this button is:
private void btnLogin_Click(object sender, RoutedEventArgs e)
{
SwitchboardView sbv = new SwitchboardView();
Applic ap = new Applic();
ap.MainGridApplic.Children.Add(sbv);
}
Could someone please help me solve this problem (what am I doing wrong...)
Kind regards
Lapeci
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For starters you're not modifying the existing Applic UserControl.
You are creating a new one and setting the SwitchboardView into that UserControl.
Then you're dropping them both on the floor!
A positive attitude may not solve every problem, but it will annoy enough people to be worth the effort.
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Hello Matt
Thank you for replying to my question.
I am really struggling on this could you please if you can help me to solve this problem, I'm new to wpf and c# honestly.
Kind regards
Lapeci
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Hello
I am playing around with the async and await keywords using .net4.5 and windows 7.
The problem is that I would like to use RenderTargetBitmap and System.Windows.Media.Imaging.BitmapEncoder to capture a UI element and return a System.Drawing.Bitmap.
The following is some test code. The problem is that it does a lot of work synchronously (e.g. using FileStream and BitmapEnocder).
For this reason, the UI blocks most of the time e.g. the UI is non-responsive.
I was hoping some of the more experienced programmers here could advise me on where I have gone wrong or how best to proceed with this function?
Many thanks for your time....
private async Task<System.Drawing.Bitmap> GetCaptureBitmap(CaptureFrame captureFrame)
{
VisualBrush brush = new VisualBrush(captureFrame);
brush.Stretch = Stretch.Fill;
brush.AlignmentX = AlignmentX.Left;
brush.AlignmentY = AlignmentY.Top;
brush.TileMode = TileMode.None;
Rectangle rect = new Rectangle();
rect.Width = Settings.Instance.Capture.Width;
rect.Height = Settings.Instance.Capture.Height;
rect.Fill = brush;
rect.Measure(new Size(rect.Width, rect.Height));
rect.Arrange(new Rect(0, 0, rect.Width, rect.Height));
System.Windows.Media.Imaging.RenderTargetBitmap bmp = new System.Windows.Media.Imaging.RenderTargetBitmap((int)rect.Width, (int)rect.Height, 96, 96, PixelFormats.Pbgra32);
bmp.Render(rect);
FileStream stream = new FileStream(System.IO.Path.GetTempFileName(), FileMode.Create, FileAccess.ReadWrite, FileShare.Read, 4096, FileOptions.DeleteOnClose);
System.Windows.Media.Imaging.BitmapEncoder encoder = new System.Windows.Media.Imaging.BmpBitmapEncoder();
encoder.Frames.Add(System.Windows.Media.Imaging.BitmapFrame.Create(bmp));
encoder.Save(stream);
stream.Flush();
System.Drawing.Bitmap bitmap = (System.Drawing.Bitmap)System.Drawing.Image.FromStream(stream, true, false);
return bitmap;
}
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I did not notice an "await" in your method, so the whole method runs synchronously.
Consider using a BackgroundWorker instead.
The "do work" handler of the BackgroundWorker can do the work in your method; the "completed" event handler can subsequently update the UI, if necessary.
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