绑定一个布尔值属性一个WinForm的背景色属性 [英] Binding a bool property to BackColor Property of a WinForm

问题描述

我有一个表格在我的的WinForm 应用程序，包含文本框这文本框绑定到姓 A 人的财产对象。

I have a Form in my WinForm application, that contains a TextBox and this TextBox bind to FirstName property of a Person Object.

public class Person
{
   string firstName;
   public string FirstName
   {
      get { return firstName; }
      set { 
           firstName = value; 
           this.isOdd = value.Length % 2;
          }
   }

   bool isOdd;  
   public bool IsOdd { get {return isOdd; } }
}

在我的应用程序运行时，这个表格节目，用户可以键入他/她的名字的文本框，我怎样才能绑定背景色的属性表格到人的 ISODD 属性对象时（ ISODD 是真 背景色集到 Col​​or.Green 键，当它是假的背景色设置为 Col​​or.Red ）？

When My application runs, this Form shows and user could types his/her name to the TextBox, How can I bind BackColor property of the Form to the IsOdd Property of Person object(when IsOdd is True BackColor set to Color.Green and when it is False the BackColor set to Color.Red)?

推荐答案

绑定在的WinForms 也有一些非常类似于 WPF 。在 WPF 已转换和是在的WinForms 这是支持由称为事件格式。你可以试试这个code：

Binding in winforms also has something very similar to wpf. In WPF you have Converter and yes in winforms it's supported by an event called Format. You can try this code:

Binding bind = new Binding("BackColor", person, "IsOdd");
bind.Format += (s, e) => {
   e.Value = (bool)e.Value ? Color.Green : Color.Red;
};
control.DataBindings.Add(bind);

对于类人，你必须修改它一点。在的WinForms 有通知的变化模式是通过一个名为事件 EventNameChanged 与名为募集<$在一起C $ C> OnEventNameChanged 。你可以找到这个模式在的WinForms 实施大多。您还可以使用 INotifyPropertyChanged的这是 WPF 更熟悉。下面是修改后的类：

For the class Person, you have to modify it a little. In winforms there is a pattern to notify changes is by using the event with name EventNameChanged together with the raiser named OnEventNameChanged. You can find this pattern is implemented mostly in winforms. You can also use INotifyPropertyChanged which is more familiar in WPF. Here is the modified class:

public class Person {
  string firstName;
  public string FirstName {
     get { return firstName; }
     set {
           firstName = value;
           IsOdd = value.Length % 2 != 0;//Note use IsOdd not isOdd
         }
  }
  bool isOdd;
  public bool IsOdd {
    get { return isOdd; }
    private set { 
         if(isOdd != value){
           isOdd = value;
           OnIsOddChanged(EventArgs.Empty);
         }
    }
    public event EventHandler IsOddChanged;
    protected virtual void OnIsOddChanged(EventArgs e) {
      var handler = IsOddChanged;
      if (handler != null) handler(this, e);
    }        
}

注意您可以使用私人组来让所有私人code更改的属性 ISODD 通过setter和，除非你有追加后，一些通知code正确通知修改，使用私有变量 ISODD 不会更改通知。这code也是测试！

NOTE You can use private set to allow all private code to change the property IsOdd via the setter and notify the changes correctly, using the private variable isOdd won't notify changes unless you have to append some notifying code after that. This code is also Tested!.

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