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I am not able to implement the INotifyPropertyChanged.
Please help



View:
<listboxitem foreground="Red" fontfamily="Verdana" fontsize="12" fontweight="Bold" verticalalignment="Center">
                    <checkbox name="baseMapChkBox" ischecked="{Binding IsBaseMapChecked,Mode=TwoWay}" horizontalalignment="Center" verticalalignment="Center">
                            <textblock text="Base Map Layer"></textblock>
                    </checkbox>
                </listboxitem>

Viewmodel:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Input;
using System.ComponentModel;
using Microsoft.Practices.Composite.Presentation.Commands;

namespace CoM_SWBaseMapModule
{
    public class BaseMapViewModel : ViewModelBase, INotifyPropertyChanged
    {
        #region Members
        private ICommand baseMapCheckCommand;
        private BaseMapService baseMapService;
        private bool isbaseMapChecked;
        private object x=null;
        #endregion

        #region Properties
        public BaseMapView BaseMapView { get; private set; }
        public MapService MapService { get; private set; }
       
        public  bool IsBaseMapChecked
        {

            get { return isbaseMapChecked; }
            set
            {
                isbaseMapChecked = value;
                OnBaseMapCheck(x);
                OnCheckPropertyChanged("IsChecked");
            }
        }
        #endregion


        #region Methods
        public BaseMapViewModel(BaseMapView baseMapView, MapService mapService)
        {
            BaseMapView = baseMapView;
            MapService = mapService;
            baseMapService = new BaseMapService();
            IsBaseMapChecked = true;

        }
        #endregion
        #region CommandProperties
       
        #endregion

        #region Private Methods
        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnCheckPropertyChanged(string propertyName)
        {
           if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("IsChecked"));
        }


        private void OnBaseMapCheck(object p)
        {
            if (isbaseMapChecked)
                baseMapService.LoadBaseMap(MapService, true);
            if (!isbaseMapChecked)
                baseMapService.LoadBaseMap(MapService, false);
        }

        #endregion

    }
}
Posted
Updated 10-Jun-10 15:51pm
v2
Comments
PSK_ 10-Jun-10 21:51pm    
Please use pre tag for code block.
jeetuoslo 11-Jun-10 0:43am    
What pre tag and where- in the Xaml ?

1 solution

Hi,

Add the UpdateSourceTrigger to the binding.For UI elements the default UpdateSourceTrigger is LostFocus.You can set the UpdateSourceTrigger=PropertyChanged inside the binding as,

XML
<checkbox name="baseMapChkBox" ischecked="{Binding IsBaseMapChecked,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" horizontalalignment="Center" verticalalignment="Center">


One more point, "IsBaseMapChecked" is the property that you defined and triggered the "IsChecked" property inside the propertychange method,you have to trigger the "IsBaseMapChecked" property inside the PropertyChanged event I think.ie.;

PropertyChanged(this, new PropertyChangedEventArgs("IsChecked"));
become
PropertyChanged(this, new PropertyChangedEventArgs("IsBaseMapChecked"));


Regards,
Vineeth
 
Share this answer
 
v2
Comments
jeetuoslo 11-Jun-10 10:03am    
Nothing happened on the UI, the checkbox is not checked when I debug the application nor there is any the method private void OnBaseMapCheck(object p)
{
if (isbaseMapChecked)
baseMapService.LoadBaseMap(MapService, true);
if (!isbaseMapChecked)
baseMapService.LoadBaseMap(MapService, false);
}
fired on the change of click status.
jeetuoslo 11-Jun-10 10:07am    
public event PropertyChangedEventHandler PropertyChanged; PropertyChanged remains null so the event method is never fired.
jeetuoslo 11-Jun-10 12:12pm    
Got the solution, forgot the set the data context of the view

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