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Archive for September, 2007

Activity Validation for Bound Properties

September 27, 2007 Leave a comment

One of the readers (Andrew) of my Pro WF book recently had a question about page 114 of the book. This page contains the code for a custom activity validator class that enforces design-time requirements. In this example, I wanted to make sure that two properties of the target activity were set at design-time.

Andrew pointed out that the code only accepts statically set values for the properties. If you set these dependency properties by binding them to another property, the validation fails. He’s right. That particular example code only demonstrates how to validate against statically set values.

To solve the problem, all you need to do is call the IsBindingSet method of the base Activity class. Here is the revised code from page 114 (Listing 3-11) that now works for statically set or bound property values:

using System;
using System.Workflow.ComponentModel.Compiler;

namespace CustomActivityComponents
{
    /// <summary>
    /// Validator for MyCustomActivity
    /// </summary>
    public class MyCustomActivityValidator : ActivityValidator
    {
        public override ValidationErrorCollection Validate(
            ValidationManager manager, object obj)
        {
            ValidationErrorCollection errors = base.Validate(manager, obj);
            //only validate a single custom activity type
            if (obj is MyCustomActivity)
            {
                MyCustomActivity activity = obj as MyCustomActivity;
                //only do validation when the activity is in a workflow
                if (activity.Parent != null)
                {
                    if (activity.MyInt == 0)
                    {
                        if (!activity.IsBindingSet(MyCustomActivity.MyIntProperty))
                        {
                            errors.Add(
                                ValidationError.GetNotSetValidationError(
                                    "MyInt"));
                        }
                    }

                    if (activity.MyString == null ||
                        activity.MyString.Length == 0)
                    {
                        if (!activity.IsBindingSet(MyCustomActivity.MyStringProperty))
                        {
                            errors.Add(new ValidationError(
                                "MyString Property is incorrect", 501));
                        }
                    }
                }
            }
            return errors;
        }
    }
}
Categories: .NET, general, technology, workflow

CE 6.0 emulator not working with VS 2005

September 5, 2007 Leave a comment

So, I’m starting to do a bit of embedded Windows development again. For this particular project, the target environment will probably be CE 6.0, so I went ahead and installed the CE 6.0 Platform Builder (eval) on my system.

My first goal was to make sure that I had a decent development environment, including a CE 6.0 emulator that I could use to test and debug my app from VS 2005. It looked like PB for CE 6.0 supported the creation of an SDK and that SDK could include an ARMV4I emulator. Great — that sounds like exactly what I needed. I quickly configured and built an OS image along with an SDK. Everything was looking good.

I installed the SDK and saw that my new CE device and emulator were available for selection within VS. Still looking good. I threw together a quick test app and hit F5 to start debugging. I selected my new emulator as the target device and waited. And waited. And waited. The emulator (version 2) started, but the OS wouldn’t deploy or boot — all I had was an emulator with a black screen and VS just sitting there hanging, trying to deploy the OS image.

Since I didn’t have much experience with this process, I figured I must be doing something wrong. Probably something very simple. After all, I was able to start the emulator and boot the image under Platform Builder, but not from my C# app in VS.

After about 2 days of researching the problem, it turns out that the KITL option in the CE 6.0 image was the problem. KITL is Kernel Independent Transport Layer and is used to debug CE devices. According to this post and a couple of others that I found, KITL and DMA (which is used by VS 2005 to communicate with a device) don’t mix very well. The solution is to turn off the “Enable KITL” option in my CE 6.0 image.

I rebuilt my image and SDK, reinstalled the SDK and tried again. This time the emulator booted up just fine, followed by my test app. Perhaps this is documented somewhere and I just missed it. In any case, thanks to Barry Bond at MS who posted this solution. He really hit one out of the park on this one (sorry).

Categories: .NET, general, technology