c# - Convert a simple WinForms app to WPF, specifically MVVM -


background: while created simple vb.net winforms app @ work consists of 1 form , 1 module. app reads , makes updates oracle database.

recently asked if learn c# wpf , mvvm when creating apps going forward. figured app simple enough try convert can learn when take on more challenging project. , have admit having difficult time. figured if mvvm part set correctly in @ least 1 part of app (the connecting/reading/verifying of employee id on database), experience enable me rest on own. don't have experience c# , don't know if got model , viewmodel correct here or if need reversed.

goal: want here type employee id in textbox , click button. if employee id exists, something. if not, display message box.

i started creating 3 folders in ide: model, view , viewmodel. created model.cs, mainwindow.xaml , viewmodel.cs.

i've made enough progress make public class verify work. but, don't know if i've done correctly @ , behavior want isn't happening.

model.cs

namespace wpf_brazekiosk.model {     public class model     {      }      public class verify     {         public const string connectionstringtooracle = "provider=oraoledb.oracle.1;data source=mpcs;user id=secret;password=secret;";         public oledbdatareader rowread;         public oledbdatareader emp_verify(string emp)         {             var conn = new oledbconnection(connectionstringtooracle);             conn.open();             string query = "select employee_id mpcs.employee employee_id = ?";             var cmd = new oledbcommand(query, conn);             cmd.parameters.addwithvalue("employee_id", emp);             rowread = cmd.executereader();             return rowread;         }     } }

viewmodel.cs

namespace wpf_brazekiosk.viewmodel {             public class viewmodel     {         private string _empid;         public string empid         {                         {                 return _empid;             }             set             {                 if (_empid == value)                 {                     return;                 }                 _empid = value;             }         }     }   }

mainwindow.xaml

<window x:class="wpf_brazekiosk.mainwindow"         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"         xmlns:local="clr-namespace:wpf_brazekiosk"         mc:ignorable="d"         title="mainwindow" height="837" width="1000">     <grid>         <textbox x:name="textbox2" height="23" margin="444,423,416,0" textwrapping="wrap" text="textbox" width="120" verticalalignment="top" horizontalalignment="center"/>         <button x:name="button" content="remove" margin="369,612,351,0" width="260" height="124" fontsize="20" verticalalignment="top" horizontalalignment="center"/>     </grid> </window>

you should add icommand property view model. please refer following blog post more information commands , used for: http://blog.magnusmontin.net/2013/06/30/handling-events-in-an-mvvm-wpf-application/. there lot more information mvvm , commands available online if search it.

once have done bind command property of button icommand property of view model , text property of textbox empid property:

<textbox x:name="textbox2" text="{binding empid}"/> <button x:name="button" content="remove" command="{binding yourcommand}"/>

...and implement logic in execute method of command, e.g.:

public class viewmodel {     public viewmodel()     {         yourcommandproperty = new delegatecommand(check);     }     private string _empid;     public string empid     {                 {             return _empid;         }         set         {             if (_empid == value)             {                 return;             }             _empid = value;         }     }      public icommand yourcommandproperty { get; }      private void check(object o)     {         //look empid here...         messagebox.show("...");     } }

don't forget set datacontext of view instance of viewmodel class:

public mainwindow() {     initializecomponent();     datacontext = new viewmodel(); }

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