Question

您好我是WPF新手，我不知道如何进行数据绑定和后面的代码，以启用和禁用我的文本框和按钮。

如果您可以告诉我如何让它在下面的示例中工作，它将帮助我完成我的项目。

XAML

<ComboBox Name="ComboBoxA"                  
          Margin="5"  
          SelectedIndex="0" SelectionChanged="ComboBoxA_SelectionChanged"  >
    <ComboBox.ItemsPanel>
        <ItemsPanelTemplate>
            <WrapPanel Orientation="Vertical" Height="Auto" Margin="5" />
        </ItemsPanelTemplate>
    </ComboBox.ItemsPanel>
    <ComboBoxItem Content="Option1" Width="72"  />
    <ComboBoxItem Content="Option2" Width="72" />
    <ComboBoxItem Content="Option3" Width="72" />
</ComboBox>

<TextBox Name="TextBoxA"
         Margin="5" 
         Width="200"   
         IsEnabled="{Binding TextBoxEnabled}" />

<Button Name="ButtonA"
        Content="Next" 
        HorizontalAlignment="left"                
        Margin="5"                 
        IsEnabled="{Binding ButtonEnabled} />

C＃

private void ComboBoxA_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    TextBoxA = new TextBox();
    ButtonA = new Button();

    if (ComboBoxAfterProcessing.SelectedIndex == 0)
    {                    
        TextBoxA.IsEnabled = false;                    
        ButtonA.IsEnabled = false;
    }
    else if (ComboBoxAfterProcessing.SelectedIndex == 1)
    {                   
        TextBoxA.IsEnabled = true;
        ButtonA.IsEnabled = true;
    }
    else if (ComboBoxAfterProcessing.SelectedIndex == 2)
    {
        TextBoxA.IsEnabled = true;
        ButtonA.IsEnabled = true;
    }
}

Answer 1

您可以将文本框和按钮的IsEnabe属性绑定到Combox的SelectedIndex 属性，您无需响应ComboBoxA_SelectionChanged事件。为了让 SelectedIndex更改您的按钮和textBox的IsEnabe，您需要在绑定中使用对流器例如：

Answer 2

写一个如下所示的类，如下所示

public class ViewMole:INotifyPropertyChanged
{
public ViewMole()
{
    ListValues = new List<string>() { "Option1", "Option2", "Option3", "Option4", 
                                       "Option5" };
}
public ICommand Click
{
    get
    {
        return new RelayCommand();
    }
}
public List<string> ListValues
{
    get;
    set;
}
string a;
public string A
{
    get
    {
        return a;
    }
    set
    {
        a = value;
        RaisePropertyChanged("A");
    }
}
int index=0;
public int SelectedIndex
{
    get
    {
        return index;
    }
    set
    {
        index = value;
        RaisePropertyChanged("SelectedIndex");
        A = ListValues[index];
        if (index == 0)
        {
            IsEnabled = false;
        }
        else
        {
            IsEnabled = true;
        }
    }
}
bool isEnabled;
public bool IsEnabled
{
    get
    {
        return isEnabled;
    }
    set
    {
        isEnabled = value;
        RaisePropertyChanged("IsEnabled");
    }
}
public event PropertyChangedEventHandler PropertyChanged;
private void RaisePropertyChanged(string propertyName)
{
    if (PropertyChanged != null)
    {
        PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }
}

}

编写另一个实现ICommand的类，如下所示。这是handel按钮点击事件

     public class RelayCommand : ICommand
    {
    public bool CanExecute(object parameter)
    {
        return true;
    }

    public event EventHandler CanExecuteChanged;

    public void Execute(object parameter)
    {
        MessageBox.Show("Button cliked");
    }
}

将您的Xaml更改为

    <ComboBox Name="ComboBoxA"  SelectedIndex="{Binding SelectedIndex, UpdateSourceTrigger=PropertyChanged}" ItemsSource="{Binding ListValues}"/>

    <TextBox Name="TextBoxA"  Margin="5"    Width="200"   Text="{Binding A}" IsEnabled="{Binding IsEnabled}"/>

    <Button Name="ButtonA"   Content="Next"   HorizontalAlignment="left" Margin="5"    Command="{Binding Click}" IsEnabled="{Binding IsEnabled}"/>

在Xmal.cs中将数据Context设置为beolw

    public MainWindow()
    {
        InitializeComponent();
        DataContext = new ViewMole();

    }

请参阅以下链接，了解为何必须使用INotifyPropertyChanged和ICommand http://wpftutorial.net/INotifyPropertyChanged.html http://msdn.microsoft.com/en-us/library/system.componentmodel.inotifypropertychanged.aspx http://msdn.microsoft.com/en-us/library/system.windows.input.icommand.aspx

数据绑定WPF XAML

2 个答案: