Silverlight-design time error

Use the design view of blend or vs 2010 to open a user control. If an error occurs (the most common is an empty reference error ),ProgramIt is possible that the control cannot be opened normally in the designer due to some restrictions during the design. How can we avoid it? You can use system. componentmodel. designerproperties. isindesigntool to determine whether the current status is designed. during the design process, do not executeCodeYou can, for example:

Public partial class productsview: usercontrol 
{
Public productsview (){
Initializecomponent ();

If (! Designerproperties. isindesigntool ){

// Call web services etc.
}
}
}

In addition, access to applicaiton or app during design also fails because they are always null during design.