IValueConverter InArgument<string> to string

Question

I understand if you want to have a TextBox control or other WPF controls in an Activity Designer, to bind it to an actual property you will need a IValueConverter.

Is there any of such converter available natively, like ArgumentToExpressionConverter? If not, how do you convert a value to InArgument and vice versa? For example if I have a TextBox and a string InArgument, I will need a ArgumentToStringConverter, don't I?

Answer 1

for the converter from argument to wpf control, I think you need to write your own converter inherited from IValueConverter

this is the sample

http://msdn.microsoft.com/en-us/library/system.windows.data.ivalueconverter.aspx

Answer 2

yes I am aware of that. My question was, how to convert Inargument<string> to string, and vice versa

Answer 3

what do you mean by vice versa?

Answer 4

sorry, i mean from Inargument<string> to string AND from string to InArgument<String>. Because i will need both Convert and ConvertBack methods, right?

Answer 5

can you have a try on this converter, it works on my machine with a custom activity having WPF textbox

 

public class ArgumentToStringConverter : IValueConverter
    {
        object IValueConverter.Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            object convertedValue = null;
            if (value != null)
            {
                ModelItem argumentModelItem = value as ModelItem;
                if (argumentModelItem != null &&
                    argumentModelItem.Properties["Expression"] != null &&
                    argumentModelItem.Properties["Expression"].Value != null)
                {
                    if (argumentModelItem.Properties["Expression"].ComputedValue.GetType() == typeof(Literal<string>))
                    {
                        convertedValue = (argumentModelItem.Properties["Expression"].ComputedValue as Literal<String>).Value;
                    }
                    else
                    {
                        convertedValue = (argumentModelItem.Properties["Expression"].ComputedValue as VisualBasicValue<string>).ExpressionText;
                    }
                }
            }
            return convertedValue;
        }

 

        object IValueConverter.ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {

            // Convert string value to InArgument<string>

            string itemContent = (string)value;

            VisualBasicValue<string> vbArgument = new VisualBasicValue<string>(itemContent);

            InArgument<string> inArgument = new InArgument<string>(vbArgument);

            return inArgument;

        }

    }

Answer 6

Hi, Louis

Here is another sample,I created it one year ago, could be helpful to you:
http://xhinker.com/2009/11/29/DotNetWF4UseTypeConverter.aspx

Regards

---

This posting is provided "AS IS" with no warranties, and confers no rights. Microsoft Online Community Support. My Blog:http://xhinker.com "Microsoft Windows Workflow Foundation 4.0 Cookbook"