2014.12.06 ASP. Three-level linkage, add employees, modify employees

(i) Level three linkage

To achieve the effect:

Code:

1Mydbdatacontext context =NewMydbdatacontext ();2     protected voidPage_Load (Objectsender, EventArgs e)3     {4         //IsPostBack If the current request is opened for the first time, it is false when it is first opened and true at all other times .5         //Add this sentence to each load page before writing the code6         if(!IsPostBack)7         {8 Showprod ();9 Showbrand ();Ten Showcar (); One         } A     } -     /// <summary> -     ///Show car name the     /// </summary> -     Private voidShowcar () -     { -         varQ = Context. Car.where (p=>p.brand==dropdownlist2.selectedvalue); +         //Binding Display -Dropdownlist3.datasource =Q; +Dropdownlist3.datatextfield ="Name"; ADropdownlist3.datavaluefield ="Code"; at Dropdownlist3.databind (); -     } -     /// <summary> -     ///Show Series name -     /// </summary> -     Private voidShowbrand () in     { -         varQ = Context. Brand.where (p=>p.prod_code==dropdownlist1.selectedvalue); toDropdownlist2.datasource =Q; +Dropdownlist2.datatextfield ="Brand_Name"; -Dropdownlist2.datavaluefield ="Brand_Code"; the Dropdownlist2.databind (); *     } $     /// <summary>Panax Notoginseng     ///Show Vendor Name -     /// </summary> the     /// <param name= "context" ></param> +     Private voidShowprod () A     { the         varQ =context. Productor; +Dropdownlist1.datasource =Q; -Dropdownlist1.datatextfield ="Prod_name"; $Dropdownlist1.datavaluefield ="Prod_code"; $ Dropdownlist1.databind (); -     } -     /// <summary> the     ///When a drop- down list maker changes the selection -     /// </summary>Wuyi     /// <param name= "Sender" ></param> the     /// <param name= "E" ></param> -     protected voidDropDownList1_SelectedIndexChanged (Objectsender, EventArgs e) Wu     { - Showbrand (); About Showcar (); $     } -     /// <summary> -     ///when the dropdown series changes the selection -     /// </summary> A     /// <param name= "Sender" ></param> +     /// <param name= "E" ></param> the     protected voidDropdownlist2_selectedindexchanged (Objectsender, EventArgs e) -     { $ Showcar (); the}

three-level linkage source code

Then hit the AutoPostBack property to True:

(unlike WinForm, b/s needs to be submitted to the server, otherwise each click on the Options page will reload, resulting in options cannot be changed)

2014.12.06 ASP. Three-level linkage, add employees, modify employees