Re: Short way defining a property with the NotifyPropertyChanged() call - WPF Discussion Boards

Re: Short way defining a property with the NotifyPropertyChanged() call

11-Jul-16 6:04

The "notify patterns" used in this case are "standard"; but not necessarily THE ONLY way.

If performance is not any issue, and UI updates are localized (usually), then simply issue a "NotifyPropertyChanged(string.Empty)" and the "UI engine" will "refresh" ALL output fields.

Used judiciously, it can make more sense to do "notifications" from your main logic than within a "setter"; particularly when it comes to real-time updates that reference multiple "outputs" for computing other outputs.

As an alternative, one can "queue" names of properties that were changed, remove duplicates, then pump them through a notify call; if that fits.

You can then leave the properties as automatic gets and setters.

Benchmark.

Kenneth Haugland13-Jul-16 4:12

Kenneth Haugland

13-Jul-16 4:12

I usually do this (took the code from somwhere but I cant remember the referance):

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows;

    /// <summary>
    ///     Implementation of <see cref="INotifyPropertyChanged" />  and Frameworkelement to simplify base drawing classes.
    /// </summary>
    public abstract class NotifierBase : INotifyPropertyChanged
    {
        /// <summary>
        ///     Multicast event for property change notifications.
        /// </summary>
        public event PropertyChangedEventHandler PropertyChanged;

        /// <summary>
        ///     Checks if a property already matches a desired value.  Sets the property and
        ///     notifies listeners only when necessary.
        /// </summary>
        /// <typeparam name="T">Type of the property.</typeparam>
        /// <param name="storage">Reference to a property with both getter and setter.</param>
        /// <param name="value">Desired value for the property.</param>
        /// <param name="propertyName">
        ///     Name of the property used to notify listeners.  This
        ///     value is optional and can be provided automatically when invoked from compilers that
        ///     support CallerMemberName.
        /// </param>
        /// <returns>
        ///     True if the value was changed, false if the existing value matched the
        ///     desired value.
        /// </returns>
        protected bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = null)
        {

            if (Equals(storage, value))
            {
                return false;
            }

            storage = value;
            this.OnPropertyChanged(propertyName);
            return true;
        }

        /// <summary>
        ///     Notifies listeners that a property value has changed.
        /// </summary>
        /// <param name="propertyName">
        ///     Name of the property used to notify listeners.  This
        ///     value is optional and can be provided automatically when invoked from compilers
        ///     that support <see cref="CallerMemberNameAttribute" />.
        /// </param>
        protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }

Then I simply call it like this:

private string m_Name ="";
public string Name
{
    get { return m_Name; }
    set
    {
        SetProperty(ref m_Name, value);
    }
}

I just have a custom snippet to deal with the proeprty coding.

Re: Short way defining a property with the NotifyPropertyChanged() call

Mycroft Holmes13-Jul-16 12:54

Mycroft Holmes

13-Jul-16 12:54

I applaud your construction but to save 1 if statement and 1 line of code. You ROI is minimal Laugh | :laugh:

I use a snippet for the entire property structure and a region surrounding all the properties. Saving half a dozen lines of code per property is just not that high on my todo list.

Never underestimate the power of human stupidity
RAH

Add column sorting to a WPF grid

Stephen Holdorf7-Jul-16 7:11

Re: Add column sorting to a WPF grid

7-Jul-16 7:11

I have a wonderful WPF grid that I downloaded from a Codeproject article below. The problem is the grid doesn't do column sorting. Has anyone modified this grid WPF grid for column sorting? Article: DataView Paging in WPF[^]

Matt T Heffron7-Jul-16 7:39

Matt T Heffron

7-Jul-16 7:39

Even though this article is 6 years old, the best place to ask this would be in the comments at the end of the article. That way the author would be notified of your question, and any additional discussion that follows would remain associated with the article for others to find in the future.

"Fairy tales do not tell children the dragons exist. Children already know that dragons exist. Fairy tales tell children the dragons can be killed."
- G.K. Chesterton

Re: Add column sorting to a WPF grid

Stephen Holdorf7-Jul-16 8:11

Re: Add column sorting to a WPF grid

7-Jul-16 8:11

You are correct. The comments after article do expand on the article itself. Unfortunately nothing about column sorting. I really want to use this for my project but it requires sorting. Any ideas?

Gerry Schmitz8-Jul-16 6:52

Single Instance WPF App - Pass Params From Second Instance To First Instance

8-Jul-16 6:52

Use a "CollectionView" to sort / filter the data source:

CollectionView Class (System.Windows.Data)[^]

Kevin Marois30-Jun-16 8:46

Kevin Marois

30-Jun-16 8:46

[REDACTED]

Found this[^]

If it's not broken, fix it until it is

modified 30-Jun-16 15:02pm.

WPF empty tabbed dashboard example code

Stephen Holdorf28-Jun-16 12:07

28-Jun-16 12:07

I am starting a new WPF project that's framework is going to be some sort of a tabbed view dashboard. In ASP I would use a master page with a tab control and a content page for each view. I am new to XAML and was hoping that someone knew of a basic article with example code to get me started. If anyone can point me in the right direction that would be great.

-- modified 28-Jun-16 18:47pm.

Pete O'Hanlon28-Jun-16 20:53

Pete O'Hanlon

28-Jun-16 20:53

You're going to have to read this[^] a few times but it should give you a fair idea about how to pull together an application that suits your needs.

This space for rent

Richard MacCutchan28-Jun-16 21:09

Richard MacCutchan

28-Jun-16 21:09

Sacha Barber[^] has written a load of excellent articles on WPF, from beginner to advanced framework.

Gerry Schmitz1-Jul-16 5:47

1-Jul-16 5:47

In WPF:

There is a "main window" that would correspond to your "master page".

You can add a WPF "Tab Control" (to the window) that can contain multiple "Tab Item" controls.

The "content" for each tab can be added directly (e.g. as Text Blocks (labels), Text Boxes, Buttons, etc.); however, one generally creates "User Controls" to package UI elements into a view / content page which would then be added to a tab (as a child).

WPF uses "styles" in a way that is similar to CSS in order to propagate styling throughout the visual tree (of UI elements).

Stephen Holdorf6-Jul-16 10:11

RaisePropertyChanged is not being called

6-Jul-16 10:11

The article below makes doing WPF views just like MVC:
<a href="http://www.codeproject.com/Tips/678020/Master-page-in-WPF">Master page in WPF?</a>[<a href="http://www.codeproject.com/Tips/678020/Master-page-in-WPF" target="_blank" title="New Window">^</a>]

Kevin Marois27-Jun-16 10:41

Kevin Marois

27-Jun-16 10:41

I have a models project with a base model. In the base model I have:

public class ModelBase : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected void RaisePropertyChanged(string propertName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertName));
        }
    }
}

The model has:

public class MonthViewDayModel : ModelBase
{
    private bool _IsVisible;
    public bool IsVisible
    {
        get { return _IsVisible; }
        set
        {
            if (_IsVisible != value)
            {
                _IsVisible = value;
                RaisePropertyChanged("IsVisible");
            }
        }
    }
}

When I step into the base the PropertyChanged event is ALWAYS null, yet I'm bound to these models in the XAML. The DataContext is being set.

What's wrong here?

If it's not broken, fix it until it is

modified 29-Jun-16 3:53am.

Re: RaisePropertyChanged is not being called

Mycroft Holmes27-Jun-16 14:27

Mycroft Holmes

27-Jun-16 14:27

This is my base model handler - you seem to missing the assignment, caveat I have not looked at this in years!

HTML

       public void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = this.PropertyChanged;

<pre>
        if (handler != null)
        {
            if (propertyName != "IsDataChanged")
            { IsDataChanged = true; }

            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }</pre>

Never underestimate the power of human stupidity
RAH

Re: RaisePropertyChanged is not being called

Bernhard Hiller27-Jun-16 21:50

Bernhard Hiller

27-Jun-16 21:50

That looks OK (though I would prefer to copy the eventhandler and test that copy for null, but that should make a difference in rare cases only).
Where did you set the break point to step into that code? Was that action initiated by some change in the GUI?

Re: RaisePropertyChanged is not being called

Jacob Himes28-Jun-16 22:28

Jacob Himes

28-Jun-16 22:28

Could you post your XAML that goes along with your view model code? From what it looks like here its all set up right on your code end.

WPF Diagram Of Logical & Visual Trees

Kevin Marois23-Jun-16 13:56

Kevin Marois

23-Jun-16 13:56

Anyone know where I can find something like[^] this except for everything in WPF?

If it's not broken, fix it until it is

Re: WPF Diagram Of Logical & Visual Trees

Gerry Schmitz24-Jun-16 3:53