How to Ping network IP or Hostname in Silverlight Application?


Pinging a network IP or Hostname is not available in Silverlight. But you can do this using WCF service. In this post I am going to implement the same thing for you. I am using Silverlight 4 here. But this can also be possible in Silverlight 3.

Create a Silverlight application with Silverlight hosting website as “ASP.NET Web Site”:

image

Now this will create a XAML page for you by default. Add one TextBox & one Button into it. We will use TextBox to enter IP Address or the Hostname & on click of the Button it will ping that entered IP or Hostname. As a limitation to the Silverlight you can’t ping directly from the client application. You need to create a WCF service & using that you can easily ping. Remember there are some limitations here too as you are pinging it from the WCF hosting server.

Let’s implement our WCF service. Create a service method named PingNetwork and pass the hostNameOrAddress as a string. This will be your IP address or the host’s DNS name. Then create an instance of System.Net.NetworkInformation.Ping & pass the required parameter to it’s “Send” method. This will return you “PingReply”. Now check the Status of the reply. There are several options available. I used only IPStatus.Success to check it and depending upon that returning true or false.

    public bool PingNetwork(string hostNameOrAddress)
    {
        bool pingStatus = false;

        using (Ping p = new Ping())
        {
            string data = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
            byte[] buffer = Encoding.ASCII.GetBytes(data);
            int timeout = 120;

            try
            {
                PingReply reply = p.Send(hostNameOrAddress, timeout, buffer);
                pingStatus = (reply.Status == IPStatus.Success);
            }
            catch (Exception)
            {
                pingStatus = false;
            }
        }

        return pingStatus;
    }

Now come to the client side implementation. Add the service reference to the Silverlight application and then call the service method with your IP Address or the DNS name of the host:

    client.PingNetworkAsync("google.com");

As it is an Asynchronous call, implement the “Completed” event for the method. In the completed event check the e.Result value. If the server is able to ping it will return true & in other case it will return false.

This is a simple implementation of the logic. As told earlier, this will ping from server & not from the client.




Silverlight: Drag And Drop ListBoxItem to Canvas (using Telerik Control)


While surfing thru different forum I noticed that, lots of people are actually facing issues while trying to implement the drag and drop feature. The main problem arises while trying to drag from a ListBox to a panel like canvas. In this post, I will go thru the steps to demonstrate such feature.

Here I will use Telerik control to give out the demonstration. You can download the trial version of the dlls from Telerik Silverlight Control Page. I have implemented the demo using Silverlight 4 Beta 1. The same thing is also possible in earlier version of Silverlight. You can download Silverlight SDK from Silverlight Site. To develop apps in Silverlight 4 you must need Visual Studio 2010 Beta 2 which you can download from Microsoft site.

So, lets go for implementing the same. Create a Silverlight project. Lets create a ListBox and a Canvas inside the LayoutRoot:

<Grid x:Name="LayoutRoot" Background="White">
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="150"/>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>
    <ListBox x:Name="lstBox" Margin="10" Grid.Column="0"/>
    <Canvas x:Name="cnvDropBox" Background="Yellow" Margin="10" Grid.Column="1"/>
</Grid>
Now in the code behind, we have to register the Drag and Drop events for the ListBox & Canvas. Use RadDragAndDropManager class to register the same. 
RadDragAndDropManager.AddDragInfoHandler(lstBox, OnDragInfo);
RadDragAndDropManager.AddDragQueryHandler(lstBox, OnDragQuery);
RadDragAndDropManager.AddDropInfoHandler(cnvDropBox, OnDropInfo);
RadDragAndDropManager.AddDropQueryHandler(cnvDropBox, OnDropQuery);

RadDragAndDropManager.SetAllowDrop(cnvDropBox, true);
The implementation of the events will be as below:
private void OnDragQuery(object sender, DragDropQueryEventArgs e)
{
    if (e.Options.Status == DragStatus.DragQuery)
    {
        var draggedListBoxItem = e.Options.Source as Image;
        e.Options.DragCue = draggedListBoxItem.Source;
        e.Options.Payload = draggedListBoxItem.Source;
    }

    e.QueryResult = true;
    e.Handled = true;
}
private void OnDragInfo(object sender, DragDropEventArgs e)
{
    if (e.Options.Status == DragStatus.DragComplete)
    {
        // comment this block if you are going to clone
        lstBox.Items.Remove(e.Options.Source);
    }
}
private void OnDropInfo(object sender, DragDropEventArgs e)
{
    var droppablePanel = e.Options.Destination;

    if (e.Options.Status == DragStatus.DropComplete && droppablePanel is Canvas)
    {
        FrameworkElement dragableControl = null;
        Point desiredPosition = new Point();
        Point currentDragPoint = e.Options.CurrentDragPoint;
        Point canvasPosition = cnvDropBox.TransformToVisual(null).Transform(new Point());

        if (e.Options.Source is Image)
        {
            // create the new instance & update the necessary properties
            // this step is require if you are going to make a clone
            Image tempDragableControl = e.Options.Source as Image;
            dragableControl = new Image() { Source = tempDragableControl.Source };
            cnvDropBox.Children.Add(dragableControl);
        }

        desiredPosition.X = currentDragPoint.X - canvasPosition.X;
        desiredPosition.Y = currentDragPoint.Y - canvasPosition.Y;
        dragableControl.SetValue(Canvas.LeftProperty, desiredPosition.X);
        dragableControl.SetValue(Canvas.TopProperty, desiredPosition.Y);
    }
}
private void OnDropQuery(object sender, DragDropQueryEventArgs e)
{
    var droppablePanel = e.Options.Destination;

    if (e.Options.Status == DragStatus.DropDestinationQuery && droppablePanel is Canvas)
    {
        e.QueryResult = true;
        e.Handled = true;
    }
}

As I am using Image inside the ListBoxItem, hence OnDragQuery I am setting the Source as an Image to the DragCue & PayLoad properties. OnDragInfo I am removing item from the ListBox. If you don’t want to remove the dragged image from the ListBox then just remove that line. OnDropInfo I am just placing the Image to the appropriate position which we will get as CurrentDragPoint in the DragDropEventArgs.

This is a sample demonstration. So, you have to explore it more to fulfil your requirement.

Download Sample Application:  Drag And Drop ListBoxItem to Canvas Demo


 
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