Dynamically Create controls using ContentControl and Converters

Dynamically Create controls using ContentControl and Converters

I have a problem to create dynamic controls in silverlight 4.

This problem is similar to the solution provided in below thread.

http://forums.silverlight.net/post/503975.aspx

Its working for static values, but its not working when i tried to use object.

My requiremnt is:

I have question table in database, which is like below.

QuestionText, AnswerControl, AnswerDefaultText, IsItmandatory

-----------------------------------------------------------------------------

Question1     TextBox              null                       Yes

QuestionText2, RadioButton,    Yes,          Yes

Question3,      ComboBox,      null,    no 

..........................................

I need to get this data into object and conver the question text into TextBlock, and based on answercontrol value, need to create controls dynamically.

I tried like as you mentioned in your post, but data is not bindind and not able to send default values as parameter values to conevrter.

My Codes are:

1)My Xaml Code:

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:SilverlightApplication5.Converter"
xmlns:question="clr-namespace:SilverlightApplication5"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="400">

</ColumnDefinition>
</ColumnDefinition>

2) Code behind file code is:

namespace SilverlightApplication5
{
public partial class DynamicControls : UserControl
{
ObservableCollection<Questions> Question;

public DynamicControls()
{
InitializeComponent();

Question = new ObservableCollection<Questions>();
Question.Add(new Questions { QuestionControl = "TextBlock", QuestionText = "What is your name?", AnswerControl = "TextBox", AnswerValues = "", DefaultValue = "" });
Question.Add(new Questions { QuestionControl = "TextBlock", QuestionText = "What is your surname?", AnswerControl = "TextBox", AnswerValues = "", DefaultValue = "" });
Question.Add(new Questions { QuestionControl = "TextBlock", QuestionText = "Sex:", AnswerControl = "ComboBox", AnswerValues = "Male,Female,Others", DefaultValue = "Select a Value" });
Question.Add(new Questions { QuestionControl = "TextBlock", QuestionText = "Marital Status", AnswerControl = "RadioButton", AnswerValues = "", DefaultValue = "Not Married" });

this.DataContext = Question;

}

}
}

3) My converter is:

namespace SilverlightApplication5.Converter
{
public class UILocatorConverter : IValueConverter
{
#region IValueConverter Members

public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
String param="This is control created dynamically";
if (parameter != null)
{
param = System.Convert.ToString(parameter);
}

switch (value.ToString())
{
case "TextBlock":
return new TextBlock() { Text = param, HorizontalAlignment=HorizontalAlignment.Center,TextWrapping=TextWrapping.NoWrap,Width=200 };
case "Button":
return new Button() { Content = param, Width=150 };
case "TextBox":
return new TextBox() { Text = param };
case "RadioButton":
return new TextBox() { };
case "ComboBox":
return new TextBox() { };

}

return null;
}

public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}

#endregion
}
}

4) My Question Class is:

namespace SilverlightApplication5
{
public class Questions
{

private string _questionControl;
public string QuestionControl {
get
{
return _questionControl;
}
set
{
_questionControl = value;

}
}

private string _questionText;
public string QuestionText
{
get
{
return _questionText;
}
set
{
_questionText = value;

}
}

private string _answerControl;
public string AnswerControl
{
get
{
return _answerControl;
}
set
{
_answerControl = value;

}
}

private string _answerValues;
public string AnswerValues
{
get
{
return _answerValues;
}
set
{
_answerValues = value;
}
}

private string _defaultValue;
public string DefaultValue
{
get
{
return _defaultValue;
}
set
{
_defaultValue = value;
}
}

}

}

My converter is not getting called, is ther any issues in this code.

Can you please help me.

Thanks In advance

Sukesh

Answers & Comments...

Answer: 1Hi,
Please refer to the code below:

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:SilverlightApplication5.Converter" xmlns:question="clr-namespace:SilverlightApplication5" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="400"> Background="White" Width="400" Height="400"> Key="UILocatorConverter" /> </ColumnDefinition> </ColumnDefinition> Grid.Column="0" /> Grid.Column="1" />

namespace SilverlightApplication5.Converter
{
    public class UILocatorConverter : IValueConverter
    {
        #region IValueConverter Members

        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            Questions question = value as Questions;
            String param = "This is control created dynamically";
            String ControlType = "TextBlock";
            if (parameter.Equals("Question"))
            {
                param = question.QuestionText;
                ControlType = question.QuestionControl;
            }
            else
            {
                param = question.AnswerValues;
                ControlType = question.AnswerControl;
            }
            switch (ControlType.ToString())
            {
                case "TextBlock":
                    return new TextBlock() { Text = param, HorizontalAlignment = HorizontalAlignment.Center, TextWrapping = TextWrapping.NoWrap, Width = 200 };
                case "Button":
                    return new Button() { Content = param, Width = 150 };
                case "TextBox":
                    return new TextBox() { Text = param };
                case "RadioButton":
                    return new TextBox() { };
                case "ComboBox":
                    return new TextBox() { };
            }
            return null;
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }

        #endregion
    }
}

You can find I changed a lot:
1.
 Bind to the Questions directly, not Questions.Questions
2.
Bind to the whole object. Then deal with the data in the converter code-behind

by : 

Answer: 2Thank you very much Otomii Lu!!!.
It worked as my expection, Thank you for your time in changing the code.
Thanks
Sukesh
by : 

Answer: 3

I am trying to get the values provided in answer control back in objects.

For that I have put Mode=TwoWay, it had asked me to provide the path value. I am bit confused on what to give in Path, since content property is already getting control object.

Still i tried to provide below values but no use.

Path=Questions   -> Converter not getting called.

Path=AnswerText  -> only answer text is sending into converter, not full object

Path=.   -> Not working

Path=DataContext  -> Full collection is sending into converter,but  not current object

Can you please help me.

Thanks 

Sukesh

by : 

Answer: 4I am able to do it throug converter itself. Here is my modified converter code, its working fine.
case "TextBox":{TextBox txtAnswer = new TextBox() { Name = question.AnswerControlID, Width = 150};Binding bind = newBinding() { Path = new PropertyPath("AnswerText"), Mode = BindingMode.TwoWay };txtAnswer.SetBinding(TextBox.TextProperty, bind);return txtAnswer;}
by :