Object Model
Syntax
| Visual Basic (Declaration) | |
|---|---|
Public Class CodecsLoadAsyncCompletedEventArgs Inherits CodecsAsyncCompletedEventArgs | |
| Visual Basic (Usage) |  Copy Code |
|---|---|
Dim instance As CodecsLoadAsyncCompletedEventArgs | |
| C# | |
|---|---|
public class CodecsLoadAsyncCompletedEventArgs : CodecsAsyncCompletedEventArgs | |
| C++/CLI | |
|---|---|
public ref class CodecsLoadAsyncCompletedEventArgs : public CodecsAsyncCompletedEventArgs | |
Example
Remarks
The RasterCodecs class supports loading image files asynchronously using the RasterCodecs.LoadAsync methods. When calling any of these methods, the caller thread will not be blocked and the method will return instantly with an instance Leadtools.RasterImage that is in a loading status (RasterImage.IsLoading set to true). You should not use the other properties of this object while the object is in loading status.
When the RasterCodecs object finishes loading the image, the various properties of the Leadtools.RasterImage will be populated with the image information and data and the RasterImage.IsLoading property will be set to false.
It is recommended that you do not poll for the RasterImage.IsLoading property to check when the image is finished loaded, instead, subscribe to the RasterCodecs.LoadAsyncCompleted event to get notification on when the RasterCodecs.LoadAsync operation is completed and if any errors occurred.
The RasterCodecs.LoadAsyncCompleted event data will also contain the same object returned from RasterCodecs.LoadAsync so you do not have to keep the original object in your application.
The RasterCodecs.LoadAsyncCompleted event use data argument object of type CodecsLoadAsyncCompletedEventArgs. This class contains the following properties:
| Property | Description |
|---|---|
| Uri, Stream and FileName |
Contains the URI, stream or file name passed to the method that initialized this asynchronous operation. Only one of these properties can be a valid value (not a null reference) at any time The property that contains a valid reference depends on what version of RasterCodecs.LoadAsync method has been called. For example, if RasterCodecs.LoadAsync(Uri uri, object userState) is being called, the CodecsAsyncCompletedEventArgs.Uri will contain the same URI passed to the method while CodecsAsyncCompletedEventArgs.Stream and CodecsAsyncCompletedEventArgs.FileName will both be null. If RasterCodecs.LoadAsync(String fileName, object userState) is being called, the CodecsAsyncCompletedEventArgs.FileName will contain the same file name string value passed to the method while CodecsAsyncCompletedEventArgs.Uri and CodecsAsyncCompletedEventArgs.Stream will both be null and so on. |
| Image |
Contains the Leadtools.RasterImage class instance that contains the image data being loaded. This instance is the same object returned from the RasterCodecs.LoadAsync method. While the asynchronous operation is running, the value of the RasterImage.IsLoading will be true indicating that the object is being populated with the image information and should not be used. Whe the asynchronous operation compelets, the RasterCodecs.LoadAsyncCompleted event will fire and Image will contain the final and ready to use object. If an error occurs, this property will be set to null and the object is disposed internally by the toolkit. |
| Error |
Contains any errors that might have occured during the asynchronous operation. You musg check this value when the RasterCodecs.LoadAsyncCompleted event fires and make sure it does not contain a valid System.Exception object. |
| Cancelled |
Contains a value indicating whether an asynchronous operation has been canceled. For example, by calling RasterCodecs.CancelAsync when using RasterCodecs.LoadAsync with a URL |
Inheritance Hierarchy
System.Object
System.EventArgs
System.ComponentModel.AsyncCompletedEventArgs
Leadtools.Codecs.CodecsAsyncCompletedEventArgs
Leadtools.Codecs.CodecsLoadAsyncCompletedEventArgs
Requirements
Target Platforms: Silverlight, Windows XP, Windows Server 2003 family, Windows Server 2008 family, Windows Vista, Windows 7, MAC OS/X (Intel Only)