Question

我正试图从WinForms迁移到WPF，并且我仍然坚持使用绑定。

我有一个标签：

    <Label Name="labelState" Content="{Binding state}" HorizontalAlignment="Right"  Margin="10,10,10,10" FontSize="12" />

在同一个userControl（名为FormInput）的cs中，我有：

 public string state { get; set; }

  public FormInput()
        {
            state = "ok";

            InitializeComponent();          
        }

为什么这不起作用？

谢谢。

Answer 1

当您在WPF中绑定某些内容时，您需要使用 INotifyPropertyChanged

实现一个类，

class TestObject : INotifyPropertyChanged
    {
        private string _state;

        public string State
        {
            get
            {
                return _state;
            }

            set
            {
                if (_state == value) return;

                _state = value;
                OnPropertyChanged("State");
            }
        }

        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        #endregion
    }

并在 FormInput

中

public FormInput()
{
  InitializeComponent();
  TestObject t = new TestObject();
  labelState.DataContext = t;
  t.State = "ok";
}

和XAML如下，

  <Label Name="labelState" Content="{Binding State}" HorizontalAlignment="Right"    >

将字符串变量绑定到标签

1 个答案: