Infragistics ultrawebgrid errors

System. nullreferenceexception: object reference is not set to the instance of the object.

Source error:

Row 220: Object key = E. cell. row. datakey; row 221: infragistics. webui. ultrawebgrid. ultraman dband band = E. cell. band; row 222: String basetable = E. cell. band. basetablename; row 223: Table = Ds. tables [basetable]; row 224:

It's just such a mistake that bothers me more than a day, and it's really annoying. With the infragistics control, I felt too guilty. I felt that I was not familiar with the content, and I did not know where the problem was. I was always afraid of making mistakes. As soon as you see the problem, sometimes it's too big to know what the problem is. Is the sample code from copy?CodeI did not write it by myself. I will be careful later.
My practice is to have two tables in a dataset: Parent and Child. I think there are any special requirements for binding. In fact, there are no special requirements, just like the DataGrid. The error occurs because I bound the data source twice. The band cannot be found. J. After commenting it out, there will be no problem. Such a problem is really unpleasant.

here, let's talk about how to install and use the infragistics control. After the installation, the first thing to do is to add it to vs. Add a new tab page in toolbox and name it netadvantage6.2. Right-click and select "add item" and select the corresponding control. Add a reference to infragistics. webui. shared.6.2 to your project, select it, and set local replication to true in its properties. Then add the DLL of the control you want to use to the reference. Otherwise, the DLL will be used for the control. When adding a control to a page, you must first add a prefix reference and then add the control. Otherwise, it cannot be displayed. Please be careful when using these precautions.