Development of the textarea control in mobile Web application (1)

In fact, I don't want to write this article, but I 've been tossing it for a long time, alas... write down and give yourself a summary. in use. net when developing mobile web, it is obvious that a control is very useful, but. net does not provide, that is, textarea, multi-line input. I Googled and found an article about how to customize this control. The original Article is here. in addition, there is a ready-made control available for download on the Asp.net website. For details, refer to here. you can go directly to the two links I provided above, or go on to look at them. I will briefly introduce code development, and then focus on the configuration issues. this is rarely mentioned in the previous article. to develop a custom control, you need to implement two classes by yourself. One is the control class that you want to derive from a control, and the other is the adapter class that is responsible for render the control ). first, we implement a class called multilinetextbox, which is derived from the textbox class. It is relatively simple to add two more attributes: Cols and rows. the Code is as follows:

Public class multilinetextbox: system. Web. UI. mobilecontrols. textbox
{

Private int _ Cols = 0;
Public int Cols
{
Get {return this. _ Cols ;}
Set {This. _ Cols = value ;}
}
Private int _ rows = 0;
Public int rows
{
Get {return this. _ rows ;}
Set {This. _ rows = value ;}
}
}

Of course, you can also put two attribute values in viewstate as in a foreigner's article. If you do not intend to disable viewstate in your program, this should be a better solution. step 2: implement a multilinetextboxadapter class derived from controladapter, and reload an attribute and a method. the Code is as follows: public class htmlmultilinetextboxadapter: system. web. UI. mobilecontrols. adapters. controladapter
{
Protected New multilinetextbox Control
{
Get {return (multilinetextbox) base. Control ;}
}
 
Public override void render (htmltextwriter writer)
{
Writer. writebegintag ("textarea ");

String rendername;
If (device. requiresattributecolonsubstitution)
{
Rendername = control. uniqueid. Replace (':',',');
}
Else
{
Rendername = control. uniqueid;
}
Writer. writeattribute ("name", rendername );
Writer. writeattribute ("Cols", Control. cols. tostring ());
Writer. writeattribute ("rows", Control. Rows. tostring ());

Writer. Write ("> ");
Writer. Write (control. Text );
Writer. writeendtag ("textarea ");

}
}

 

The overload of attribute control indicates that the class I want to manage is multilinetextbox. the reload render method is specific to how to express this control on the page, that is, to output a textarea tag. step 3: Modify the web. config to add support for the device. I am stuck in this step... submit it first, and then discuss it later.