Passing a parameter to a User Control,

Create a User Control and add below image control inside User Control as:-

<asp:ImageButton id="ImageButton1" runat="server"></asp:ImageButton> 

Create a property called source:-

public string source   
{  
    get   
    {  
        return ImageButton1.ImageUrl;  
    }  
    set   
    {  
        ImageButton1.ImageUrl = value;  
    }  
}  

Now in our webform:
Drag and drop User Control and set the source property as:-

<uc1:UCImageButton source = "view.jpg" Id = "UCImageButton1" 
runat = "server"></uc1:UCImageButton>