Adding/Removing Dynamic Web TWAIN object individually

Starting with version 12.1, you can dynamically add/remove a specified Dynamic Web TWAIN object by using the following methods

Dynamsoft.WebTwainEnv.CreateDWTObject(id, OnSuccessCallback, OnFailureCallback)
Dynamsoft.WebTwainEnv.DeleteDWTObject(id)

The first method is pretty self-explanatory—it helps us to create a new Dynamic Web TWAIN object by passing in the id of the DWT container(generally, a div element on the page) as well as the IP and Ports the new object should be connecting to. The second allows us to remove a Dynamic Web TWAIN object from the web page by specifying its container id.

 

Add a Dynamic Web TWAIN object at runtime

 

To add a Dynamic Web TWAIN object on the web page, you should put a div element as the container for Dynamic Web TWAIN:

<div id="dwtcontrolContainer2"></div>

The next step is to use the Dynamsoft.WebTwainEnv.CreateDWTObject method to create and initialize a new Dynamic Web TWAIN object that is embedded in the div with id 'dwtcontrolContainer2'. Here’s what it looks like in code:

var DWObject2; 
Dynamsoft.WebTwainEnv.CreateDWTObject( 
  "dwtcontrolContainer2", "192.168.3.1", 18618, 18619,
  function(DWTObject){ 
    DWObject2 = DWTObject;
  }, 
  function(errorString){ 
    alert(errorString);
} );

Please NOTE that the new object is initialized and then passed to the callback function OnSuccessCallback where you can assign it to a variable like DWObject2. Then, you can start to manipulate the new object. For example:

DWObject2.Width = 580;
DWObject2.Height = 600;
DWObject2.SelectSource();
DWObject2.AcquireImage();

NOTE:

  1. If the div element with id “dwtcontrolContainer2” already exists in the Dynamsoft.WebTwainEnv.Containers in the file dynamsoft.webtwain.config.js like the following

    Dynamsoft.WebTwainEnv.Containers = [{ContainerId:'dwtcontrolContainer', Width: 120, Height: 350}, {ContainerId:'dwtcontrolContainer2', Width: 270, Height: 350}];
    

    you will get the following error:

    Duplicate ID detected for creating Dynamic Web TWAIN objects, please check and modify.

    In this case, please change or remove the following from dynamsoft.webtwain.config.js

    {ContainerId:'dwtcontrolContainer2', Width: 270, Height: 350}
    

Remove a Dynamic Web TWAIN object at runtime

To remove a Dynamic Web TWAIN object from the web page, it is quite easy. You just need to call the Dynamsoft.WebTwainEnv.DeleteDWTObject(id) method by providing the container id.

Dynamsoft.WebTwainEnv.DeleteDWTObject("dwtcontrolContainer2");

NOTE:
Dynamsoft.WebTwainEnv.Unload() can’t release the Dynamic Web TWAIN object generated by Dynamsoft.WebTwainEnv.CreateDWTObject(id, OnSuccessCallback, OnFailureCallback). You can only use the Dynamsoft.WebTwainEnv.DeleteDWTObject(id) method to release that object.

Is this page helpful?

Leave a Reply

Your email address will not be published.