CODEWITHSUNDEEP
c#winformsdevexpress
Robert
Robert

Reputation: 1726

Change value of all controls of a specific type without causing indefinite loop

I have a situation where I have several (let's say 10 for now) DevExpress LookUpEdit controls (sort of like DropDown Controls for Windows) on several tabs on my form. All 10 of these controls are the same in that they use the same data source to get their information from. What I'm trying to do is if a value changes in ANY of the 10 controls, then I want it to change in the other 9 controls as well. Because I have other controls of this type on my form that I do not want to be changed, I simply added a string value to the Tag property and have a method search for all controls of this type with the Tag property set to a specific string.

I initially thought I might be able to create a generic method that would change the text for all other controls and assign it to the TextChanged event of each control but I soon found out that they cancel each other out once I assign the value of one control to another (because in essence, once I change the value of one control, it then calls the same method and tries to change the rest).

Sorry if it's confusing, but here's some code as to what I'm trying to do...for now, let's say I have just 2 controls...lookupWeight and lookupBicycleWeight. On the TextChanged event for each, I have this:

    private void OnLookupWeight_TextChanged(object sender, EventArgs e)
    {
        OnLookupWeight_TextChanged<LookUpEdit>(sender, e);
    }

which calls this:

    private void OnLookupWeight_TextChanged<T>(object sender, EventArgs e)
    {
        var controls = GetAll(tabPageSpecifications, typeof(T));

        foreach (var control in controls)
        {
            if (control.Tag != null)
                if (control.Tag.ToString() == "Weight")
                    if(control.Name != (sender as LookUpEdit).Name)
                        (control as LookUpEdit).EditValue = (sender as LookUpEdit).Text;
        }

    }

GetAll is a simple method that returns all controls for a given Control, including sub-controls:

    /// <summary>
    /// method to get all child & sub-child controls within a control by type
    /// </summary>
    /// <param name="control">the control we're searching in (use this for the form)</param>
    /// <param name="type">The control type we're looking for (i.e; TextBox)</param>
    /// <returns></returns>
    public IEnumerable<Control> GetAll(Control control, Type type = null)
    {
        var controls = control.Controls.Cast<Control>();
        //check the all value, if true then get all the controls
        //otherwise get the controls of the specified type
        if (type == null)
            return controls.SelectMany(ctrl => GetAll(ctrl, type)).Concat(controls);
        else
            return controls.SelectMany(ctrl => GetAll(ctrl, type)).Concat(controls).Where(c => c.GetType() == type);
    }

I know my OnLookupWeight_TextChanged method isn't entirely generic because I cast to the type LookupEdit but I am just trying to get this to work at this point before going back and changing things.

As you can see, the line if(control.Name != (sender as LookUpEdit).Name) is where the OnLookupWeight_TextChanged gets fired again and basically cancels itself out.

Any help or diretion as to how to accomplish this would be great.

Upvotes: 3

Views: 922

Answers (3)

Stig
Stig

Reputation: 1323

Why don't you use the same bindingsource for all the 10 controls?

When you change the selected value in one of them all would change.

Upvotes: 0

Paul Anderson
Paul Anderson

Reputation: 1180

It sounds like the code in OnLookupWeight_TextChanged shouldn't be run when the text of the control is changed from within that routine. You can use an instance variable to disable running it except when the change comes from outside. For example:

    private Boolean InProgress;
    private void OnLookupWeight_TextChanged<T>(object sender, EventArgs e)
    {
        if (!InProgress)
        {
            InProgress=true;
            var controls = GetAll(tabPageSpecifications, typeof(T));

            foreach (var control in controls)
            {
                 if (control.Tag != null)
                     if (control.Tag.ToString() == "Weight")
                         if(control.Name != (sender as LookUpEdit).Name)
                             (control as LookUpEdit).EditValue = (sender as LookUpEdit).Text;
            }
            InProgress = false;
        }
    }

Upvotes: 0

Idle_Mind
Idle_Mind

Reputation: 39122

Just change the ones that don't already have the same Text value:

    foreach (var control in controls)
    {
        if (control.Tag != null)
            if (control.Tag.ToString() == "Weight")
                if((control as LookUpEdit).EditValue != (sender as LookUpEdit).Text)
                    (control as LookUpEdit).EditValue = (sender as LookUpEdit).Text;
    }

Upvotes: 1

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