Im trying to implement undo and redo using gdi in wpf. I am not very familiar with gdi and my attempts have been unsuccessful.

On my mouse move event I draw like this:

   using (var g = Gdi.Graphics.FromImage(tempBitmap))
    {
        g.SmoothingMode = Gdi.Drawing2D.SmoothingMode.AntiAlias;
        g.CompositingQuality = Gdi.Drawing2D.CompositingQuality.HighQuality;
        if (currentTool == "eraserBrush")
            g.CompositingMode = Gdi.Drawing2D.CompositingMode.SourceCopy;
        else
            g.CompositingMode = Gdi.Drawing2D.CompositingMode.SourceOver;
        g.DrawLine(pen,p0,p1);
    }

    // Copy GDI bitmap to WPF bitmap.
    var hbmp = tempBitmap.GetHbitmap();
    var options = BitmapSizeOptions.FromEmptyOptions();
    this.writableBmp.Source = Imaging.CreateBitmapSourceFromHBitmap(hbmp,
        IntPtr.Zero, Int32Rect.Empty, options);

    // Redraw the WPF Image control.
    this.writableBmp.InvalidateMeasure();
    this.writableBmp.InvalidateVisual();

tempBitmap is a Gdi bitmap

On my mouse up event I push tempBitmap to a stack, and on my undo event I pop from the stack and do the following:

if (paintStack.Count <= 1)
                    return;

                paintStack.Pop();
                tempBitmap = paintStack.Peek();
 var hbmp = paintStack.Peek().GetHbitmap();
                var options = BitmapSizeOptions.FromEmptyOptions();
                this.writableBmp.Source = Imaging.CreateBitmapSourceFromHBitmap(hbmp,
                    IntPtr.Zero, Int32Rect.Empty, options);

                // Redraw the WPF Image control.
                this.writableBmp.InvalidateMeasure();
                this.writableBmp.InvalidateVisual();

C-Pad is what i intrepret as cmd and notepad programming.I have done VB.Net and C# with C-Pad successfully--given any complicated programme.Even with 250 textboxes,12 butons etc etc.

 I am trying the same with wpf.I am not geting a grip of it.Can any expert suggest a simple programme where in a simple wpf programme--say messagebox with "Hello,world" is achieved.I shall follow it up from there.I am getting difficulty in calling the compiler and also how to compile the xaml file with vb file.Thanks in advance.

   I am not a professional programmer.I am aged 68 and is interested in prgrammming as a hobby.

Thanks in advance.

Venkatraman

We have a legacy application written in Smalltalk that is currently tightly coupled to a dotnet module that it starts through COM. We are now developing a new Dot net application that will need to be run separately to this legacy application. In order to do this we are trying to register the new application on the running objects table, and then pick up the running object through a Dotnet Com interface when the legacy application runs.

So far I've managed to get the object registered on the running object table, and accepting calls from the client application.  However I can't work out how to attach to the events that I'm declaring on the server object.

Demo Application can be downloaded from https://skydrive.live.com/redir?resid=A36A8BD9FDD6DC54!24421

Can anyone help please?

Hi all, now that WPF is cool again ;) I wanted to share some Material Design WPF stuff I've been working on.  

https://github.com/ButchersBoy/MaterialDesignInXamlToolkit

Thanks,

James

Hi,

I am trying to record camera feed, front or back camera, of the surface pro 3 in my WPF application. I am using directx capture to achieve this. But i am not able to record. I get the message saying that the camera is in use. The same application works on Surface pro 2? Did anyone face the same problem?

Thanks,

Rajesh

Hi,

in my datagrid I insert a TextBlock and ComboBox for edit cell.

When I click in the cell for edit, my Convert is called two times.

I not understand why.

XAML

<DataGridTemplateColumn Header="{StaticResource datagridDay}"><DataGridTemplateColumn.CellTemplate><DataTemplate><TextBlock Text="{Binding Day, Mode=TwoWay}" /></DataTemplate></DataGridTemplateColumn.CellTemplate><DataGridTemplateColumn.CellEditingTemplate><DataTemplate><ComboBox Name="dgCmbDay" DataContext="{Binding}" DisplayMemberPath="Items"><ComboBox.ItemsSource><MultiBinding Converter="{StaticResource DateNumNameConverter}" ><MultiBinding.Bindings><Binding ElementName="dgPlan" Path="CurrentItem"/><Binding Source="{StaticResource AnalysisPlanViewModel}" Path="ListDayNameOfWeek"/><Binding Source="{StaticResource AnalysisPlanViewModel}" Path="ListDayNumOfMonth"/><Binding Path="Items"></Binding></MultiBinding.Bindings></MultiBinding></ComboBox.ItemsSource></ComboBox></DataTemplate></DataGridTemplateColumn.CellEditingTemplate></DataGridTemplateColumn>

My Converter:

    public class DayNumName : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            if (values == null || values.Length < 4)
                return null;

            AnalysisPlanItemExt analisysPlanItem = (AnalysisPlanItemExt)values[0];
            List<string> listDayOfWeek = (List<string>)values[1];
            List<string> listDayNumOfMonth = (List<string>)values[2];

            if (analisysPlanItem.Type != null)
            {
                //Day of Weeks
                if (analisysPlanItem.Type.Value.Equals(Definition.SchedTypeEnum.DayOfWeek))
                    return listDayOfWeek;

                if (analisysPlanItem.Type.Value.Equals(Definition.SchedTypeEnum.DayOfMonth))
                    return listDayNumOfMonth;
            }

            return null;
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new System.NotImplementedException();
        }
    }

I'm trying to create a specified button which switch images every time it pressed, without using the Click CBFunction, so I'm using toggle button and triggers (checked unchecked) and I want this button to supply DP of string so who ever uses is button will only have to specify the images paths and a click CBFuntion toperform what ever he wishes.

I managed to create the mechanism for switching images with triggers(but the triggers image paths are hard coded and not using DP) and to enable setting a click CBFunction. When I switch the hard coded image path with a DP which return a string with the path the program crush, an exception is thrown.

U.C xaml:

<UserControl x:Class="ButtonChangeImage.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             mc:Ignorable="d"><Grid><ToggleButton x:Name="btnCI"><ToggleButton.Content ><Image Name="img" Source="C:\Users\AmitL\Desktop\joecocker.jpg"/></ToggleButton.Content><ToggleButton.Triggers><EventTrigger RoutedEvent="ToggleButton.Checked"><EventTrigger.Actions><BeginStoryboard><Storyboard><ObjectAnimationUsingKeyFrames Storyboard.Target="{x:Reference img}" Storyboard.TargetProperty="Source"><DiscreteObjectKeyFrame KeyTime="0:0:0"><DiscreteObjectKeyFrame.Value><BitmapImage UriSource="{Binding FirstImage}"/><!--<BitmapImage UriSource="C:\Users\AmitL\Desktop\james-brown-010.jpg"/>--><!--if I switch to this line it works fine!--></DiscreteObjectKeyFrame.Value></DiscreteObjectKeyFrame></ObjectAnimationUsingKeyFrames></Storyboard></BeginStoryboard></EventTrigger.Actions></EventTrigger><EventTrigger RoutedEvent="ToggleButton.Unchecked"><EventTrigger.Actions><BeginStoryboard><Storyboard><ObjectAnimationUsingKeyFrames Storyboard.Target="{x:Reference img}" Storyboard.TargetProperty="Source"><DiscreteObjectKeyFrame KeyTime="0:0:0"><DiscreteObjectKeyFrame.Value><BitmapImage UriSource="C:\Users\AmitL\Desktop\joecocker.jpg"/></DiscreteObjectKeyFrame.Value></DiscreteObjectKeyFrame></ObjectAnimationUsingKeyFrames></Storyboard></BeginStoryboard></EventTrigger.Actions></EventTrigger></ToggleButton.Triggers></ToggleButton></Grid></UserControl>

U.C cs:

public partial class UserControl1 : UserControl
    {
        public static readonly DependencyProperty FirstImageDP  = DependencyProperty.Register("FirstImage", typeof(string), typeof(UserControl1), new PropertyMetadata(@"C:\Users\AmitL\Desktop\james-brown-010.jpg", new PropertyChangedCallback(FirstImageSource)));

        private string m_strFirstImage = string.Empty;
        private BitmapImage m_oBMImage = null;

        private static void FirstImageSource(DependencyObject obj, DependencyPropertyChangedEventArgs args)
        {
            UserControl1 l_UCBtnSwitchImage = (UserControl1)obj;
            l_UCBtnSwitchImage.m_strFirstImage = (string)args.NewValue;

            l_UCBtnSwitchImage.m_oBMImage = new BitmapImage(new Uri(l_UCBtnSwitchImage.m_strFirstImage, UriKind.Absolute));
        }

        public string FirstImage
        {
            get
            {
                string l_strTemp = (string)GetValue(FirstImageDP);
                return l_strTemp;
            }
            set
            {
                SetValue(FirstImageDP, value);
            }
        }

        public event RoutedEventHandler Click
        {
            add { btnCI.Click += value; }
            remove { btnCI.Click -= value; }
        }

        public UserControl1()
        {
            InitializeComponent();
        }
    }

<Window x:Class="ButtonChangeImage.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:m="clr-namespace:ButtonChangeImage"
        Title="MainWindow" Height="350" Width="525"><Grid><m:UserControl1 Click="ToggleButton_Checked" FirstImage="C:\Users\AmitL\Desktop\james-brown-010.jpg"></m:UserControl1></Grid></Window>

The exception:

I would love to know why when I switch the hard coded value with DP it suddenly throw exception, how to fix it or if there is other way to achieve U.C with those demands.
Thanks.

Hi,

in my datagrid I insert a TextBlock and ComboBox for edit cell.

When I click in the cell for edit and I select an item of combox, the item selected is not shown in cell of DataGrid.

Why?

XAML

<DataGridTemplateColumn Header="{StaticResource datagridDay}"><DataGridTemplateColumn.CellTemplate><DataTemplate><TextBlock Text="{Binding Day, Mode=TwoWay}" /></DataTemplate></DataGridTemplateColumn.CellTemplate><DataGridTemplateColumn.CellEditingTemplate><DataTemplate><ComboBox Name="dgCmbDay" DataContext="{Binding}" DisplayMemberPath="Items"><ComboBox.ItemsSource><MultiBinding Converter="{StaticResource DateNumNameConverter}" ><MultiBinding.Bindings><Binding ElementName="dgPlan" Path="CurrentItem"/><Binding Source="{StaticResource AnalysisPlanViewModel}" Path="ListDayNameOfWeek"/><Binding Source="{StaticResource AnalysisPlanViewModel}" Path="ListDayNumOfMonth"/><Binding Path="Items"></Binding></MultiBinding.Bindings></MultiBinding></ComboBox.ItemsSource></ComboBox></DataTemplate></DataGridTemplateColumn.CellEditingTemplate></DataGridTemplateColumn>

My Converter:

    public class DayNumName : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            if (values == null || values.Length < 4)
                return null;

            AnalysisPlanItemExt analisysPlanItem = (AnalysisPlanItemExt)values[0];
            List<string> listDayOfWeek = (List<string>)values[1];
            List<string> listDayNumOfMonth = (List<string>)values[2];

            if (analisysPlanItem.Type != null)
            {
                //Day of Weeks
                if (analisysPlanItem.Type.Value.Equals(Definition.SchedTypeEnum.DayOfWeek))
                    return listDayOfWeek;

                if (analisysPlanItem.Type.Value.Equals(Definition.SchedTypeEnum.DayOfMonth))
                    return listDayNumOfMonth;
            }

            return null;
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new System.NotImplementedException();
        }
    }

Hi All,

We are using C#.net, WPF to build a visualization application to mathematically design 3d models for optimization and interface it with Pro E Wildfire. We are able to derive the unstructured wireframe of the model, but would like to view it with a structured (uniform rectangular) wireframe. Also we want to see if there are ways in WPF with which one can peform stress / Force analysis on the 3d model. Is there any external API compatible with WPF available that can be made use of.

Every single direction/ clue is appreciated.

ThanKs n regards,
RM

how to restrict how many characters to type in DataGrid cell?

For an example, if one column only allow 20 characters, if type more than 20 character, it do nothing. thx!

JaneC

How to restrict how many characters to type in DataGrid cell?

Do we need to set any DataGrid property? Thx

JaneC

I created a sample project (VS2012) which populates some datagrids using Entity Framework against sql server 2008 R2 (using DBContext).  I can also add rows to the database from my sample Project.  This is where I use the Delegate command.  Everything appears to work correctly, but, basically, I kludged this together (through trial and error) and now ask the following so that I have at least some idea what I'm doing -- source code below.  My issue is that in the in the command that I bind to an "Add Row" button in the view -- for the Delegate command (the way I set it up) I have

--sample A -- in the DelegateCommand class

private Action<object> m_Action;
public DelegateCommand(Action<object> action)
{
    this.m_Action = action;
}

as opposed to

--Sample B -- I omit the <object> here and get an error

private Action m_Action;
public DelegateCommand(Action action)
{
    this.m_Action = action;
}

because without the <object> type identifier -- I get a complaint from

public void Execute(object parameter)
{
    m_Action(parameter);
}

--Error 1 Delegate 'System.Action' does not take 1 arguments

If I re- add <object> as in sample A then the error goes away.

Based on the following source code -- my question is if it would be possible to modify my setup here so that I don't have to add the <object> for the Action, and what would that look like?  This is purely an exercise, as I would prefer to know what I'm doing rather than just kludging stuff together -- like in public ICommand AddRowCommand section -- it does not appear to matter if I have a "set" -- the project performs correctly with or with out the "set".  The idea is to not be writing code based on "luck", but based on I know what I'm doing.

--code in ViewModel

public void AddRow()
{
   if (this.AuthorID != null && this.AuthorName != null)
   {
       var flds = new Author { AuthorId = int.Parse(this.AuthorID), AuthorName = this.AuthorName };
       ctx.Authors.Add(flds);
       ctx.SaveChanges();
       FillAuthors();
       Console.WriteLine("Row Added!");
    }
    else
       MessageBox.Show("cannot insert a blank row", "No values to insert", MessageBoxButton.OK, MessageBoxImage.Exclamation);
}

private ICommand _addRowCommand;
public ICommand AddRowCommand
{
   get
   {
       if (_addRowCommand == null)
       {
           _addRowCommand = new DelegateCommand((abc) => AddRow());
       }
           return _addRowCommand;
    }
    //--I noticed that it does not seem to make a difference if I have a set{ _addRowCommand = value; } here
}

public class DelegateCommand : ICommand
{
    private Action<object> m_Action;
    public DelegateCommand(Action<object> action)
    {
        this.m_Action = action;
    }
    public bool CanExecute(object parameter)
    {
        return true;
    }

    public event EventHandler CanExecuteChanged;

    public void Execute(object parameter)
    {
        m_Action(parameter);
    }
}

Rich P

I'm testing how frequently WPF display can change when I have one window per monitor. My frame rate isn't amazing, and using xperf and GPUView it looks like WPF prepares both windows and then calls "Present packet" on both at the same time, and waits for both to complete before moving on to send the next frames to the video card. I think my frame rate could have been faster if WPF didn't wait for the present to complete on both displays. When I run two WPF processes, each with one window on one monitor, the present packets are independent, so parallel processing is more efficient and the frame rate is higher.

Did anyone observe the same behavior? Is there a flag I can set to make the WPF windows of one process more independent? 

I get a list of HOLEID from an SQL database.
I load these into a MVVM ViewModel using a SQL Query

I can display the fields of a ListView (UserGrid)  selected item in a Textbox by using.

Text="{Binding SelectedItem.HoleID, ElementName-"UserGrid"}".

I have a second ListView which should retrieve related records from another SQL table which I can do although I have to get them all as I haven't figured out how to load only once an item is selected in the first ListView.

What I would like is to then filter the second ListView (UserGrid2) by the selected item in the first.

I currently display the (UserGrid2) ListView by using a DataContext and DisplayMemberBinding for header and autogenerate rows.

Thanks

Is there a way that I can refresh the items in my DataGrid?. I am using C#. Some says that DataGrid.Items.Refresh() is the solution, but it doesn't work. Here's a snippet of my code.

namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {

        MongoClient mongoClient { get; set; }
        MongoServer server { get; set; }
        MongoDatabase database { get; set; }
        MongoCollection<facultyData> collection { get; set; }


        public MainWindow()
        {
            InitializeComponent();

            loginDialog dlg = new loginDialog();
            dlg.ShowDialog();



            var dateTime = DateTime.Now;
            dateTime_label.Content = dateTime;

        }

        public void Window_Loaded(object sender, RoutedEventArgs e)
        {

                MongoClient mongoClient = new MongoClient();
                MongoServer server = mongoClient.GetServer();
                MongoDatabase database = server.GetDatabase("facultyDataAndSchedule");
                MongoCollection<facultyData> collection = database.GetCollection<facultyData>("faculty");
                var results = collection.FindAll();
                List<facultyData> resultList = results.ToList<facultyData>();
                // Bind result data to WPF view.
                if (resultList.Count() > 0)
                {
                    Binding bind = new Binding(); //create a new binding to be used on the wpf
                    facultyDataGrid.DataContext = resultList; //sets the data binding for the control
                    facultyDataGrid.SetBinding(DataGrid.ItemsSourceProperty, bind); //syncs the data
                    facultyID_Textbox.DataContext = resultList;
                    facultyID_Textbox.SetBinding(DataGrid.ItemsSourceProperty, bind);
                    lastName_TextBox.DataContext = resultList;
                    lastName_TextBox.SetBinding(DataGrid.ItemsSourceProperty, bind);




                }


        }

        private void viewMenu_click(object sender, RoutedEventArgs e)
        {
            MessageBox.Show("Hello", "hiThere");
        }

        private void fRViewMenu_click(object sender, RoutedEventArgs e)
        {
            documentViewer docViewer = new documentViewer();
            docViewer.ShowDialog();
        }

        private void selectionChanged(object sender, SelectionChangedEventArgs e)
        {
            facultyData row = (facultyData)facultyDataGrid.SelectedItem;
            facultyID_Textbox.Text = row.facultyID;
            lastName_TextBox.Text = row.lastName;
            firstName_TextBox.Text = row.firstName;
            middleName_TextBox.Text = row.middleName;
            age_TextBox.Text = row.age.ToString();
        }

        public void addData_Click(object sender, RoutedEventArgs e)
        {
            var connectionString = "mongodb://localhost";
            var client = new MongoClient(connectionString);
            var server = client.GetServer();
            var database = server.GetDatabase("facultyDataAndSchedule");
            var collection = database.GetCollection<facultyData>("faculty");



                var entity = new facultyData { facultyID = facultyID_Textbox.Text.ToString(),
                    age= Int32.Parse(age_TextBox.Text),
                    firstName= firstName_TextBox.Text.ToString(),
                    lastName = lastName_TextBox.Text.ToString(),
                    middleName = middleName_TextBox.Text.ToString(),
                    dateOfBirth="11/11/2011",
                    program= "progra", rank="gegs", services="gegsg", status="geh", yearsOfTeachingO=1, yearsOfTeachingS=1};
                collection.Insert(entity);


        }

        private void refreshButton_Click(object sender, RoutedEventArgs e)
        {

        }
    }

    class facultyData
    {
        public ObjectId _id { get; set; }
        public string facultyID { get; set; }
        public string acadYear { get; set; }
        public string program { get; set; }
        public string lastName { get; set; }
        public string firstName { get; set; }
        public string middleName { get; set; }
        public string dateOfBirth { get; set; }

    }



}

Hello,

I want to make a palm gesture in my project to clean the drawn area, is it possible to make a palm gesture in wpf?.

If it is not possible to make palmgesture in wpf , can i use full handgesture to do same work in wpf?.