Can't Resolve name on element

Question

What is the Error in This Code? , I Have Exception :

Can't resolve name on Element

I Try to make validation using behaviors , try this before the logic code right

// I have class called BooleanToObjectConverter

        <local:BooleanToObjectConverter x:Key="boolToStyleImage"                                               x:TypeArguments="Style">

            <local:BooleanToObjectConverter.FalseObject>
                <Style TargetType="Image">
                    <Setter Property="HeightRequest" Value="20" />
                    <Setter Property="Source" Value="{local:ImageResource MVVM_Demo_And_Service.Images.error.png}" />
                </Style>
            </local:BooleanToObjectConverter.FalseObject>

            <local:BooleanToObjectConverter.TrueObject>
                <Style TargetType="Image">
                    <Setter Property="HeightRequest" Value="20" />
                    <Setter Property="Source" Value="{local:ImageResource MVVM_Demo_And_Service.Images.success.png}" />
                </Style>
            </local:BooleanToObjectConverter.TrueObject>
        </local:BooleanToObjectConverter>

        <Style x:Key="baseStyle"
         TargetType="Label">
            <Setter Property="FontSize" Value="Micro" />
            <Setter Property="FontAttributes" Value="Italic" />
        </Style>
        <local:BooleanToObjectConverter x:Key="boolToStyleName"
                                       x:TypeArguments="Style">
            <local:BooleanToObjectConverter.FalseObject>
                <Style TargetType="Label" BasedOn="{StaticResource baseStyle}">
                    <Setter Property="TextColor" Value="#F44336" />
                    <Setter Property="Text" Value="Enter your Name " />
                </Style>
            </local:BooleanToObjectConverter.FalseObject>

            <local:BooleanToObjectConverter.TrueObject>
                <Style TargetType="Label" BasedOn="{StaticResource baseStyle}">
                    <Setter Property="TextColor" Value="#4CAF50" />
                    <Setter Property="Text" Value="Good" />
                </Style>
            </local:BooleanToObjectConverter.TrueObject>

        </local:BooleanToObjectConverter>
        <local:BooleanToObjectConverter x:Key="boolToStyleEmail"
                                       x:TypeArguments="Style">
            <local:BooleanToObjectConverter.FalseObject>
                <Style TargetType="Label" BasedOn="{StaticResource baseStyle}">
                    <Setter Property="TextColor" Value="#F44336" />
                    <Setter Property="Text" Value="Enter a valid email" />
                </Style>
            </local:BooleanToObjectConverter.FalseObject>

            <local:BooleanToObjectConverter.TrueObject>
                <Style TargetType="Label" BasedOn="{StaticResource baseStyle}">
                    <Setter Property="TextColor" Value="#4CAF50" />
                    <Setter Property="Text" Value="Your email looks good" />
                </Style>
            </local:BooleanToObjectConverter.TrueObject>

        </local:BooleanToObjectConverter>

        <local:BooleanToObjectConverter x:Key="boolToStyleAge"
                                       x:TypeArguments="Style">
            <local:BooleanToObjectConverter.FalseObject>
                <Style TargetType="Label" BasedOn="{StaticResource baseStyle}">
                    <Setter Property="TextColor" Value="#F44336" />
                    <Setter Property="Text" Value="Enter numeric values" />
                </Style>
            </local:BooleanToObjectConverter.FalseObject>

            <local:BooleanToObjectConverter.TrueObject>
                <Style TargetType="Label" BasedOn="{StaticResource baseStyle}">
                    <Setter Property="TextColor" Value="#4CAF50" />
                    <Setter Property="Text" Value="You are very young!" />
                </Style>
            </local:BooleanToObjectConverter.TrueObject>

        </local:BooleanToObjectConverter>
        <local:BooleanToObjectConverter x:Key="boolToStylePassword"
                                       x:TypeArguments="Style">
            <local:BooleanToObjectConverter.FalseObject>
                <Style TargetType="Label" BasedOn="{StaticResource baseStyle}">
                    <Setter Property="TextColor" Value="#F44336" />
                    <Setter Property="Text" Value="Enter numeric values" />
                </Style>
            </local:BooleanToObjectConverter.FalseObject>

            <local:BooleanToObjectConverter.TrueObject>
                <Style TargetType="Label" BasedOn="{StaticResource baseStyle}">
                    <Setter Property="TextColor" Value="#4CAF50" />
                    <Setter Property="Text" Value="You are very Complex!" />
                </Style>
            </local:BooleanToObjectConverter.TrueObject>

        </local:BooleanToObjectConverter>
        <local:GenderConverter x:Key="genderConverter" />
    </ResourceDictionary>
</ContentPage.Resources>
<StackLayout>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition />
            <RowDefinition />
            <RowDefinition />
            <RowDefinition />
            <RowDefinition />
            <RowDefinition />

        </Grid.RowDefinitions>

        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto" />
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="40" />
        </Grid.ColumnDefinitions>
        <Entry Grid.Row="0" Grid.Column="1" Placeholder="UserName"
            Text="{Binding SelectedUser.UserName, Mode=TwoWay}" 
            x:Name="NameEntry" >
            <Entry.Behaviors>
                <local:MaxLengthValidator MaxLength="10"/>
            </Entry.Behaviors>
        </Entry>
        <Image Grid.Row="0" Grid.Column="2" x:Name="NameSucessErrorImage"
                 Style="{Binding Source={x:Reference nameValidator}, 
                            Path=IsValid, 
                            Converter={StaticResource boolToStyleImage}}"/>
        <Label Grid.Row="1" Grid.Column="1" Style="{Binding Source={x:Reference nameValidator}, 
                            Path=IsValid, 
                            Converter={StaticResource boolToStyleName}}" />

        <Entry Grid.Row="2" Grid.Column="1" Placeholder="Password"
            Text="{Binding SelectedUser.UserPassword, Mode=TwoWay}" 
             x:Name="PassEntry" >
            <Entry.Behaviors>
                <local:NumberValidatorBehavior x:Name="passwordValidator"/>
                <local:MaxLengthValidator MaxLength="15"/>
            </Entry.Behaviors>
        </Entry>
        <Image Grid.Row="2" Grid.Column="2" x:Name="passSuccessErrorImage"
              Style="{Binding Source={x:Reference passwordValidator}, 
                            Path=IsValid, 
                            Converter={StaticResource boolToStyleImage}}"/>
        <Label Grid.Row="3" Grid.Column="1" Style="{Binding Source={x:Reference passwordValidator}, 
                            Path=IsValid, 
                            Converter={StaticResource boolToStylePassword}}" />

        <Entry Grid.Row="3" Grid.Column="1" Text="{Binding SelectedUser.UserAge, Mode=TwoWay}" 
               x:Name="AgeEntry" >
            <Entry.Behaviors>
                <local:NumberValidatorBehavior x:Name="ageValidator"/>
                <local:MaxLengthValidator MaxLength="2"/>
            </Entry.Behaviors>
        </Entry>
        <Image Grid.Row="3" Grid.Column="2" x:Name="ageSuccessErrorImage"
              Style="{Binding Source={x:Reference ageValidator}, 
                            Path=IsValid, 
                            Converter={StaticResource boolToStyleImage}}"/>
        <Label Grid.Row="4" Grid.Column="1" Style="{Binding Source={x:Reference ageValidator}, 
                            Path=IsValid, 
                            Converter={StaticResource boolToStyleAge}}" />



    </Grid>
    <Button Text="ADD User" 
           Command="{Binding PostCommand}" Clicked="Button_Clicked"  />

       </StackLayout>

Any help ?

Answer 1

I Solved it , the error was in :

 <Entry Grid.Row="0" Grid.Column="1" Placeholder="UserName"
        Text="{Binding SelectedUser.UserName, Mode=TwoWay}" 
        x:Name="NameEntry" >
        <Entry.Behaviors>
            <local:MaxLengthValidator MaxLength="10" x:Name="nameValidator"/>
        </Entry.Behaviors>
    </Entry>
    <Image Grid.Row="0" Grid.Column="2" x:Name="NameSucessErrorImage"
             Style="{Binding Source={x:Reference nameValidator}, 
                        Path=IsValid, 
                        Converter={StaticResource boolToStyleImage}}"/>
    <Label Grid.Row="1" Grid.Column="1" Style="{Binding Source={x:Reference nameValidator}, 
                        Path=IsValid, 
                        Converter={StaticResource boolToStyleName}}" />

I didn't define x:Name="nameValidator" at local:MaxLengthValidator tag to reference to Behavior in image and label tag.