RadMaskedEditBox with nullable value

[Michael]

Hi,

I can't seem to figure out the right control to use for my task.  I tried RadMaskedEditBox with all type of masking type and RadSpinEditor, but neither can get me what I need.  Here is what I need:

1. This control must allow to enter only numeric values.

2. This control has to be binded to a nullable integer. 

3. This control need to allow me to delete the value leaving it blank, which should assign null to the binded property.  Vice versa, if I set value of the binded property to null, then control should not contain any values.

Any suggestions?

Thank you in advance.

 

[Dimitar]

Hi Michael,

Thank you for writing.

To achieve this you can use a standard mask. In addition, you will need to handle the Parse event and handle the null values. Here is a complete example for this:

public partial class Form1 : Form
{
    MyData data = new MyData() { Value = 300 };
    public Form1()
    {
        InitializeComponent();

        radMaskedEditBox1.MaskType = Telerik.WinControls.UI.MaskType.Standard;
        radMaskedEditBox1.Mask = "999";

        radMaskedEditBox1.TextMaskFormat = MaskFormat.ExcludePromptAndLiterals;

        Binding binding = new Binding("Value", data, "Value", true);
        binding.Parse += Binding_Parse;

        radMaskedEditBox1.DataBindings.Add(binding);
    }

    private void Binding_Parse(object sender, ConvertEventArgs e)
    {
        if (e.Value == "" && e.DesiredType == typeof(int?))
        {
            e.Value = null;
        }
    }

    private void radButton1_Click(object sender, EventArgs e)
    {
        data.Value = null;

    }

    private void radButton2_Click(object sender, EventArgs e)
    {
        Console.WriteLine(data.Value);
    }
}
class MyData :  INotifyPropertyChanged
{
    int? nullableValue = null;

    public int? Value
    {
        get
        {
            return nullableValue;
        }
        set
        {
            nullableValue = value;
            OnPropertyChanged("Value");
        }
    }
    protected virtual void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
    public event PropertyChangedEventHandler PropertyChanged;
}

I hope this will be useful. 

Regards,
Dimitar
Telerik

[Michael]

Hi,

 

It has been a while since I asked the question above, but thank you for your prompt reply.  I am developing another program where I need another control for currency, but I need to be binded to a nullable decimal property.  I've inherited from your RadMaskedEditBox control and was able to make it work, but I have 2 outstanding issues.

 

1. I used your suggestion above to handle Parse event of Binding object to handle null values.  But is it possible to integrate this into my control so that I don't have to worry about handling this property each time I bind this control.

2. When user selects the whole text and presses delete, I would like for the Value to be set to 0.  But it seems like $0.00 is always substituted there. 

Please take a look at my code below and let me know what else I can do to handle 2 situations above.

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Linq;
using System.Text;
using Telerik.WinControls.Analytics;
using Telerik.WinControls.UI;

namespace AllergyCanada.WinControls.UI
{
    public class MidexCurrencyEditBox : RadMaskedEditBox
    {
        public MidexCurrencyEditBox() : base()
        {
            MaskType = Telerik.WinControls.UI.MaskType.Numeric;
            Mask = "C2";
            TextAlign = System.Windows.Forms.HorizontalAlignment.Right;
            MidexCurrencyEditBox radMaskedEditBox = this;
            base.ValueChanged += new EventHandler(radMaskedEditBox.OnCurrencyValueChanged);
            MidexCurrencyEditBox radMaskedEditBox1 = this;
            base.ValueChanging += new CancelEventHandler(radMaskedEditBox1.OnCurrencyValueChanging);
        }


        protected override void Dispose(bool disposing)
        {
            MidexCurrencyEditBox radMaskedEditBox = this;
            base.ValueChanged -= new EventHandler(radMaskedEditBox.OnCurrencyValueChanged);
            MidexCurrencyEditBox radMaskedEditBox1 = this;
            base.ValueChanging -= new CancelEventHandler(radMaskedEditBox1.OnCurrencyValueChanging);
            base.Dispose(disposing);
        }


        [Bindable(true)]
        [Browsable(true)]
        [Category("Behavior")]
        [DefaultValue("")]
        [Description("Gets or sets the value associated to the mask edit box")]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public decimal? CurrencyValue
        {
            get
            {
                if (base.MaskedEditBoxElement.Value == null)
                    return null;

                return decimal.Parse(base.MaskedEditBoxElement.Value.ToString(), NumberStyles.Currency);
            }
            set
            {
                base.MaskedEditBoxElement.Value = value;
                OnNotifyPropertyChanged("CurrencyValue");
            }
        }

        /// <summary>
        /// Occurs when the editing value has been changed
        /// </summary>
        [Category("Action")]
        [Description("Occurs when the editing currency value has been changed")]
        public event EventHandler CurrencyValueChanged;


        /// <summary>
        /// Occurs when the editing value is changing.
        /// </summary>
        [Category("Action")]
        [Description(" Occurs when the editing currency value is changing.")]
        public event CancelEventHandler CurrencyValueChanging;


        protected virtual void OnCurrencyValueChanged(object sender, EventArgs e)
        {
            this.CurrencyValueChanged?.Invoke(this, e);
            this.OnNotifyPropertyChanged("CurrencyValue");
            ControlTraceMonitor.TrackAtomicFeature(this, "CurrencyValueChanged", this.Text);
        }

        /// <summary>
        /// Fires the ValueChanging event
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected virtual void OnCurrencyValueChanging(object sender, CancelEventArgs e)
        {
            this.CurrencyValueChanging?.Invoke(this, e);
        }

    }
}

[Dimitar]

Hello Michael,

Thank you for writing back.

1. Yes this is possible, you will need to use the DataBindings CollectioChanged event to determine when a binding is added:

public MidexCurrencyEditBox() : base()
{
   //other code omitted

    DataBindings.CollectionChanged += DataBindings_CollectionChanged;
}

private void DataBindings_CollectionChanged(object sender, CollectionChangeEventArgs e)
{
    if (e.Action == CollectionChangeAction.Add && e.Element is Binding)
    {
        var binding = e.Element as Binding;
        binding.Parse += Binding_Parse;
    }
}

2. Please note that the format in the masked edit box depends on the mask and it cannot be changed for particular values only. 

I hope this will be useful. Let me know if you have additional questions.

Regards,
Dimitar
Telerik by Progress