CODEWITHSUNDEEP
c#wpfmvvm
user3848454
user3848454

Reputation: 11

multibinding not update source property and database

i m using mvvm pattern with wpf and Entity framework and implemented INotifyPropertyChanged in viewmodel and model

im using Multibinding with 3 textbox control, first textbox for entry first name secend textbox for last name

and third textbox for Full name

third textbox using multibinding:

 <TextBox >
   <TextBox.Text>
        <MultiBinding Converter="{StaticResource FullNameConverter}">
                            <Binding Path="PersonData.FullName" Mode="TwoWay"         ValidatesOnDataErrors="True" UpdateSourceTrigger="PropertyChanged"/>

                            <Binding ElementName="FirstNameTextBox"  Path="Text" Mode="TwoWay"       UpdateSourceTrigger="PropertyChanged" />
                            <Binding ElementName="LastNameTextBox" Path="Text"    Mode="TwoWay"     UpdateSourceTrigger="PropertyChanged"/>

                       </MultiBinding>
                    </TextBox.Text>
                </TextBox>

this is my convertor

public class FullNameConverter : IMultiValueConverter
{

    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        return string.Format("{0} {1}", values[1], values[2]);
      }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        return new[] { value };  
      }
}

this work perfectly and save FirstName And LastName to database but not save FullName to database with multibinding.

but when entry Directly in FullName TextBox Save Data To database

how to resolve this problem? please help me thanks

Upvotes: 0

Views: 275

Answers (2)

user3848454
user3848454

Reputation: 11

Thank you sheridan FullName Infact is a alias of First and last name. Example:if First Name is Lionel And LastName is Messi, Multibinding Full Name=Lionel Messi But Sometimes i want change Full Name to Custom Nmae ,Example:Lionel Messi To Lio

Upvotes: 0

Sheridan
Sheridan

Reputation: 69979

MultiBindings do not work in the way that you seem to think they do. You cannot use one to create a new value to save in the database. They can only be used to create a new value to display in the UI. If you want to create a new value to save in the database, then you'll need to create property for that in code... perhaps something like this?:

public string Fullname
{
    get { return string.Format("{0} {1}", FirstName, LastName); }
}

Of course, to do this, you would also need to have properties named FirstName and LastName which are data bound to the first two TextBoxes, but then you're supposed to be doing that anyway. In this case, you should also data bind this aggregated property to the third TextBox.Text property in the UI:

<TextBox Text="{Binding FullName}" />

Please read the Data Binding Overview page on MSDN to find out more about how you should be writing your WPF code.

Upvotes: 2

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