Jag har försökt att bygga upp en slideshow med effekter men det går illa.
Först så försökte jag med Ajax, men fick inte ihop det för effekterna.
Sen hittade jag följande: (ber om ursäkt för att det är ganska så mycket kod)
<script type="text/javascript">
//A timer will be fired in 5 seconds to call getNextImage()
var c_interval = 5000;
window.setTimeout("getNextImage()", c_interval);
function getNextImage()
{
//Send the request to server with the current image url as the
argument
CallServer(document.getElementById("photo").src, "");
}
function ReceiveServerData(rValue)
{
//Receive server's response of a string rValue, which is
prepared in the server's function
//GetCallbackResult()
var wds = rValue.split(";");
//Assign the transition effect
document.getElementById("photo").style.filter = wds[1];
//Preload the image file from server.
When finishing download, imageLoaded function will be called
//with the img object as the argument
var img = new Image();
img.onload = function(){ imageLoaded(this); }
img.onerror = function(){ imageError(this); }
img.onabort = function(){ imageError(this); }
img.src = wds[0];
}
function imageError(img)
{
//If image download errors occur, this function will be called.
window.setTimeout("getNextImage()", 1000);
}
function imageLoaded(img)
{
var photo = document.getElementById("photo"); //Find the image control object
photo.filters[0].apply(); //Apply the transition effect
photo.filters[0].play(); //Play the effect and display the new image
photo.ImageUrl = GetNextImageUrl();
//Assign the image to the image control
window.setTimeout("getNextImage()", c_interval);
//Initiate the next request
}
</script>
<asp:Image ID="photo" runat="server" Height="160px" ImageUrl="~/Image/danmark_kopenhamn_tivoli.jpg"/>
// i codebehind
string m_lastFileName = "none";
if (IsPostBack)
return;
//photo.Src = GetNextImageUrl();
photo.ImageUrl = GetNextImageUrl();
//Register Ajax client script to client's browsers.
This has to be hard coded.
string cbReference = Page.ClientScript.GetCallbackEventReference
(this, "arg", "ReceiveServerData", "context");
string callbackScript = "function CallServer(arg, context)" + "{ " +
cbReference + "} ;";
Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "CallServer",
callbackScript, true);
public void RaiseCallbackEvent(string eventArgument)
{
//This is first place to receive the callback from client's browser.
The parameter 'eventArgument'
//is the parameter passed from the Javascript's call 'CallServer()'.
In this example, it is the
//last image url.
m_lastFileName = Path.GetFileName(eventArgument);
}
public string GetCallbackResult()
{
//This is the second call triggled by the 'CallServer()' and it is the place
to prepare and return a string
//to the client. Here the returned string is the image url and the
transition effect.
return GetNextImageUrl() + ";" + GetNextTransition();
}
private string GetNextImageUrl()
{
//Randomly pick a image file in the server.
string[] files = Directory.GetFiles
(AppDomain.CurrentDomain.BaseDirectory + "Image", "*.jpg");
if (files.Length == 0)
return string.Empty;
while (true)
{
int n = (int)((files.Length - 1) * (new Random()).NextDouble());
//Do not want to repeat the last image
if (files[n].IndexOf(m_lastFileName) < 0)
{
return files[n].Replace(AppDomain.CurrentDomain.BaseDirectory,
string.Empty);
}
}
}
private string GetNextTransition()
{ //Randomly pick a transition effect. Note some of the effects
only work in IE.
int n = (int)((new Random().NextDouble()) * 5);
switch (n)
{
case 0:
case 1:
n = (int)((new Random().NextDouble()) * 22);
return "revealTrans(duration=2,transition=" + n.ToString() + ")";
case 2:
case 3:
if (Request.Browser.Browser == "IE")
{
n = (int)((new Random().NextDouble()) * 8);
switch (n)
{
case 0:
return "progid:DXImageTransform.Microsoft.RandomDissolve()";
case 1:
return "progid:DXImageTransform.Microsoft.Pixelate(MaxSquare=20,
Duration=2, Enabled=false)";
case 2:
return "progid:DXImageTransform.Microsoft.RadialWipe(wipeStyle='clock')";
case 3:
return "progid:DXImageTransform.Microsoft.Wheel(spokes=4)";
case 4:
return "progid:DXImageTransform.Microsoft.Stretch(stretchStyle='spin')";
default:
return "progid:DXImageTransform.Microsoft.Stretch(stretchStyle='push')";
}
}
else
return "blendTrans(duration=2)";
default:
return "blendTrans(duration=2)";
}
}
Jag får följande error
Det gick inte att hitta målet för återanropet (__Page), eller så implementerar
målet inte ICallbackEventHandler.
och då pekar den på
string cbReference = Page.ClientScript.GetCallbackEventReference
(this, "arg", "ReceiveServerData", "context");