Setting up common properties to a set controls

问题

I'm inside a function that repaints certain controls inside a form, it is implemented as an extension method for the ControlCollection class like this:

void SetColorsCorrespondingToVisualStudioTheme(this Control.ControlCollection controls)
{
  foreach (var control in controls)
  {
  ...

Inside this method, the code that sets some GUI properties that are common to a set of controls:

  ...
    if (controlType == typeof(TreeView))
    {
      ((TreeView)control).BorderStyle = BorderStyle.None;
      ((TreeView)control).BackColor = EditorBackgroundColor;
      ((TreeView)control).ForeColor = FontColor;
      continue;
    }

    if (controlType == typeof(TextBox))
    {
      ((TextBox)control).BorderStyle = BorderStyle.None;
      ((TextBox)control).BackColor = EditorBackgroundColor;
      ((TextBox)control).ForeColor = FontColor;
    }
 ...

I'll like to know if there is a way refactor the code to be reused like:

    if (controlType == typeof(TreeView) || controlType == typeof(TextBox))
    {
      ((controlType)control).BorderStyle = BorderStyle.None;
      ((controlType)control).BackColor = EditorBackgroundColor;
      ((controlType)control).ForeColor = FontColor;
    }

The code above obviously doesn't work because controlType is a variable and not a type but the intention of what I'm trying to do is what matters. I've also tried:

((typeof(controlType))control).B...

The only option I can think of now is to create custom controls for the base types (TreeView, TextBox, etc,) and make all of them implement a common interface so I can use them interchangeably:

 ...
    if (controlType == typeof(TreeView) || controlType == typeof(TextBox))
    {
      //CustomControl() ñ 
      ICustomControl newControl = new CustomControl(control);      
      newControl.BorderStyle = BorderStyle.None;
      newControl.BackColor = EditorBackgroundColor;
      newControl.ForeColor = FontColor;
    }
...
    public class CustomTreeView : ICustomControl
    {
...
    public class CustomTextBox : ICustomControl
    {
...
    public interface ICustomControl
    {
       public BorderStyle BorderStyle {get; set;}
       public Color BackColor {get; set;}
       public Color ForeColor {get; set;}
...

but that (at least in my head) sounds worse than keeping the multiple if's. am I missing another approach you may know to solve this problem?

回答1:

if (control is TreeView || control is TextBox)
{
  ((Control)control).BorderStyle = BorderStyle.None;
  ((Control)control).BackColor = EditorBackgroundColor;
  ((Control)control).ForeColor = FontColor;
}

回答2:

I would probably create a struct to keep the desired values for the properties, and a method that takes a parameter of type Control and apply the style on it:

struct ThemeStyle
{
    ThemeStyle(Color backColor, Color foreColor, BorderStyle borderStyle)
    {
        this.BackColor = backColor;
        this.ForeColor = foreColor;
        this.BorderStyle = borderStyle;
    }
    public Color BackColor {get; private set;}
    public Color ForeColor {get; private set;}
    public BorderStyle BorderStyle {get; private set;}

    public void Apply(Control c)
    {
        c.BackColor = this.BackColor;
        switch(typeof(c))
        {
             case typeof(TreeView):
             case typeof(TextBox):
               c.BorderStyle = this.BorderStyle;
             break;
        }
    }
}

Note: this code is only a demonstration, written directly here using a cellphone. There might be some mistakes.

Then in your loop all you need to do is call the Apply method with the control.

来源：https://stackoverflow.com/questions/31251750/setting-up-common-properties-to-a-set-controls

标签

reusability