Here is the post which gives you how to get the Silverlight version through Javascript.
http://www.kunal-chowdhury.com/2010/09/how-to-detect-installed-silverlight.html
If you want to get the Silverlight version inside Silverlight code you may invoke this function as follows.
http://silverlightedweb.blogspot.com/2008/05/silverlight-javascript-communication.html
One of the previous posts in my general programming blog talks about evaluating the arithmetic expressions using the DataColumn and DataTables.The requirement was simple.You are given with an arithmetic expression say “(2+2)*3” as string. May be a user entered expression.You need to evaluate the given expression and show the answer.
In .Net it is easier.Use a DataColumn with the given expression and it will calculate the result for you.But when we come to Silverlight the things get harder.There is no concept of DataSet or DataTable in Silverlight.Rather the ADO.Net is not there.So what can we do?
One solution is to have a WCF server call which accepts the expression as string and use the ADO.Net DataColumn at server-side and return back the result.Obviously you can achieve that since the server is just a .Net application with ADO.Net support.But is that the better solution? I will say No because we have another alternative.
Its nothing but the famous eval function of javascript.I think all of you know how Silverlight can communicate with Javascript.If not please read this post about the same.
Here goes the solution.Get your expression.Pass it to the eval method of HtmlWindow.Use the return value properly.
private double Evaluate(string expression)
{
object obj = HtmlPage.Window.Eval(expression);
return Convert.ToDouble(obj);
}
Here is the solution which I promised to give in one of my older posts titled Javascripting silverlight.I delayed because this post needs some prerequisites which I discussed in the below posts.
[ScriptableType]
public partial class Page : UserControl
{
public Page()
{
InitializeComponent();
HtmlPage.RegisterScriptableObject("mainpage", this);
}
private void sldr_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
HtmlPage.Window.Invoke("ValueChanged", sldr.Value);
}
[ScriptableMember]
public void SetValue(double d)
{
sldr.Value = d;
}
<head runat="server">
<title>Test Page For SilverlightApplication1</title>
<script language="javascript">
function ValueChanged(value)
{
var Host1 = document.getElementById("Xaml1");
var Host2 = document.getElementById("Xaml2");
Host1.content.mainpage.SetValue(value);
Host2.content.mainpage.SetValue(value);
}
function clicked()
{
var name=document.getElementById("txt");
var val=parseFloat(name.value);
if(val!=null){
ValueChanged(val);
}
}
</script>
</head>
<body style="height:300;margin:0;">
<form id="form1" runat="server" style="height:300;">
<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
<div style="height:300;">
<asp:Silverlight ID="Xaml1" runat="server" Source="~/ClientBin/SilverlightApplication1.xap" Version="2.0" Width="300" Height="300" />
</div>
<br /> <hr />
<marquee> <a href="#">HTML area</a></marquee>
<hr />
<input type="text" id="txt" value="50" />
<button onclick="clicked()">Change value</button>
<div style="height:300;">
<asp:Silverlight ID="Xaml2" runat="server" Source="~/ClientBin/SilverlightApplication1.xap" Version="2.0" Width="300" Height="300" />
</div>
</form>
</body>
Sample available hereSimply,this is the managed code representation of complex javascript objects.
Confused?? Here is one scenario.Suppose there is a method in Javascript which returns a string value.We will call that method by simply executing HtmlPage.Invoke() method and process the return value as needed in silverlight.
This is possible because the javascipt function returns string.There is a proper mapping in silverlight to accept the value.What to do if javascript has to return the following object.
function GetDetails()
{
var me={Name:'joy',Company:'identitymine'};
return me;
}
private void btn_Click(object sender, RoutedEventArgs e){
ScriptObject obj = HtmlPage.Window.Invoke("GetDetails", "");
txtName.Text = (string)obj.GetProperty("Name");
}
Please have a look at my previous post which handles the communication in a easy way.Better use that technique whenever required.But Of course as per your requirements it may vary.
As I told in the earlier post we need to have understanding about Scriptable attribute,ScriptObject etc.I have listed some links which I feel explains the concept well.
[ScriptableType]
public partial class Page : UserControl {
public Page(){
InitializeComponent();
HtmlPage.RegisterScriptableObject("mainpage", this);
}
[ScriptableMember]
public void SetData(double val){
sldr.Value = val;//sldr is an object of Slider
}
}
var Host = document.getElementById("Xaml1");//Xaml1 is id of Silverlight Control
Host.content.mainpage.SetData(val);
<head runat="server">
<title>Test Page For SilverlightApplication1title>
<script language="javascript">1: function setvalue() {2: var v=document.getElementById("txt");3: var val=parseFloat(v.value);4: var Host = document.getElementById("Xaml1");5: Host.content.mainpage.SetData(val);6: }</script>
</head>
<body style="height:300;margin:0;">
<form id="form1" runat="server" style="height:300;">
<asp:ScriptManager ID="ScriptManager1" runat="server">asp:ScriptManager>
<div style="height:300;">
<asp:Silverlight ID="Xaml1" runat="server" Source="~/ClientBin/SilverlightApplication1.xap" Version="2.0" Width="300" Height="300" />
</div>
<br />
<a href="#">HTML Areaa><br />
<input type="text" id="txt" /> <button onclick="setvalue()">Update Sliderbutton>
</form>
</body>
Sample available here.
private void Button_Click(object sender, RoutedEventArgs e){
System.Windows.Browser.HtmlPage.Window.Invoke("ShowMsg", txtInput.Text);
}
function ShowMsg(msg)
{
alert(msg);
}
function GetData()
{
var reply = prompt("What's your name?", "");
return (reply);
}
private void Button_Click_1(object sender, RoutedEventArgs e){
string o=(string)System.Windows.Browser.HtmlPage.Window.Invoke("GetData", "");
txtOutput.Text = o;
}
As the heading implies ,here I am going to explain about "Using Javascript with Silverlight 2.0".
<asp:Silverlight ID="Xaml1" runat="server" Source="~/ClientBin/SilverlightApplication2.xap" Version="2.0" Width="100%" Height="100%" OnPluginLoaded="plloaded" />
<script language="javascript">1: function grd_MouseLeftButtonDown(sender,args){2: alert("Clicked on " + sender.name);3: }4: function plloaded(sender,th)5: {6: var i=sender.get_element();7: var grd=i.Content.findName("LayoutRoot");//LayoutRoot is the Grid Present in Page.Xaml8: grd.AddEventListener("MouseLeftButtonDown", "grd_MouseLeftButtonDown")9: }</script>
Its done this will invoke the grd_MouseLeftButtonDown function on mouse click of Grid present in Xaml.
A sample which implements this method is located here
