Macromedia Flash Professional 8 UNLEASHED [Electronic resources] نسخه متنی

File Upload

One of the most exciting new features of Flash is the capability to download and upload files directly from your SWF. Flash accomplishes this by means of the FileReference object.

The FileReference object allows you to browse for files with the browse() method. You can even tell Flash what types of files you want the end user to be able to select. And when a user selects a file, the FileReference will have these available properties:

• creationDate
  A Date object representing the creation date of the file on the users computer.

• creator
  The Mac creator type of the file on the user's computer.

• modificationDate
  A Date object representing the last modified date of the file.

• name
  The name of the file.

• size
  The size of the file in bytes.

• type
  The file type of the file.

Following is an example that will allow you to select a file and then display all the information in the Output panel.

//import the FileReference Object
import flash.net.FileReference;
//the file reference object
var file_fr:FileReference = new FileReference();
//object for listening to for FileRefernce events
var list_obj:Object = new Object();
//the event for when a user selects a file and hits open
list_obj.onSelect = function(){
trace("name: "+file_fr.name);
trace("creation date: "+file_fr.creationDate);
trace("modification date: "+file_fr.modificationDate);
trace("type: "+file_fr.type);
trace("size in bytes: "+file_fr.size);
trace("creator: "+file_fr.creator);
}
//add the listener to the FileReference object
file_fr.addListener(list_obj);
//event for the Button component
browse_butn.clickHandler = function(){
file_fr.browse();
}

This code does quite a few things. First, it imports the necessary class file for the FileReference object. Then it creates a generic object to use as a listener for the onSelect event that is triggered when a user selects a file and clicks Open. Then we create the actual event callback for the listener object. Next the listener object is added to our FileReference. And finally, we create the event for the Button component, so that when the button is clicked, the File Browse window will appear.

Test this movie, and when you select a file and click Open, you should see some information about the file in the Output panel, as shown in Figure 1.15.