internal class DelegateCommand : ICommand
{
private readonly Action _execute;
private readonly Func<bool> _canExecute;
public DelegateCommand(Action execute) : this(execute, null) { }
public DelegateCommand(Action execute, Func<bool> canExecute)
{
_execute = execute ?? throw new ArgumentNullException(nameof(execute));
_canExecute = canExecute;
}
public void Execute(object parameter)
{
_execute();
}
public bool CanExecute(object parameter)
{
if (_canExecute == null) return true;
return _canExecute();
}
public event EventHandler CanExecuteChanged
{
add => CommandManager.RequerySuggested += value;
remove => CommandManager.RequerySuggested -= value;
}
}
internal class DelegateCommand<T> : ICommand
{
private readonly Action<T> _execute;
private readonly Func<bool> _canExecute;
public DelegateCommand(Action<T> execute) : this(execute, null) { }
public DelegateCommand(Action<T> execute, Func<bool> canExecute)
{
_execute = execute ?? throw new ArgumentNullException(nameof(execute));
_canExecute = canExecute;
}
public void Execute(object parameter)
{
_execute((T)parameter);
}
public bool CanExecute(object parameter)
{
if (_canExecute == null) return true;
return _canExecute();
}
public event EventHandler CanExecuteChanged
{
add => CommandManager.RequerySuggested += value;
remove => CommandManager.RequerySuggested -= value;
}
}
<Window x:Class="WpfApp21.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:viewModels="clr-namespace:WpfApp21.ViewModels"
xmlns:local="clr-namespace:WpfApp21"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Window.DataContext>
<viewModels:SearchWordViewModel/>
</Window.DataContext>
<StackPanel>
<TextBox x:Name="InputTextBox"></TextBox>
<Button Command="{Binding SearchCommand}" CommandParameter="{Binding ElementName=InputTextBox,Path=Text}"></Button>
<Image Source="{Binding Name}" />
</StackPanel>
</Window>
public class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public virtual void OnPropertyChanged([CallerMemberName] string PropertyChanged = null)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs(PropertyChanged));
}
}
}
public class MainViewModel : ViewModelBase
{
private BitmapImage name;
public BitmapImage Name
{
get { return name; }
set { name = value; OnPropertyChanged(); }
}
public MainViewModel()
{
Name = new BitmapImage(new System.Uri("https://dss0.baidu.com/6ONWsjip0QIZ8tyhnq/it/u=1758912268,304734450&fm=55&app=54&f=JPEG?w=1140&h=640", System.UriKind.RelativeOrAbsolute));
}
}
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