C# 命令模式是如何工作的?
我正在做:C# 命令模式是如何工作的?,c#,wpf,binding,C#,Wpf,Binding,我正在做: <Button Style="{StaticResource buttonstyle}" HorizontalAlignment="Left" Margin="12,21,10,0" VerticalAlignment="Top" Height="78" Width="83" BorderThickness="2" Content="add event"
<Button
Style="{StaticResource buttonstyle}"
HorizontalAlignment="Left" Margin="12,21,10,0"
VerticalAlignment="Top" Height="78" Width="83"
BorderThickness="2" Content="add event"
Command="{Binding NewEvent}"
CommandParameter="This is the report."
>
</Button>
当我点击按钮时什么都没发生,我做错了什么?有人能帮我理解我的错误吗
谢谢你
编辑我应该提到,这是编剧写的:
System.Windows.Data错误:40:BindingExpression路径错误:在“对象”“viewModel”(HashCode=18612316)上找不到“NewEvent”属性。BindingExpression:Path=NewEvent;DataItem='viewModel'(HashCode=18612316);目标元素是“按钮”(名称=“”);目标属性是“Command”(键入“ICommand”)首先,检查绑定是否绑定。在运行时,可以在VisualStudio的输出窗口中看到绑定错误。或者,您可以在某个地方设置一个断点,并在调试器中查看按钮的
命令的值(您需要为按钮指定一个名称,以便在调试器中轻松访问它:问题已经解决:属性应该是公共的,然后一切正常。我希望我的spp是xmal驱动的,因此当有人替换代码时,它将是可移植的
public class StringDelegateCommand : ICommand
{
//methodes without return value
Action<string> m_ExecuteTargets = delegate { };
//methodes without parmtters inside
Func<bool> m_CanExecuteTargets = delegate { return false; };
//the value whom allows execution
bool m_Enabled = false;
#region ICommand Members
public bool CanExecute(object parameter)
{
Delegate[] targets = m_CanExecuteTargets.GetInvocationList();
foreach (Func<bool> target in targets)
{
m_Enabled = false;
bool localEnable = target.Invoke();
if (localEnable)
{
m_Enabled = true;
break;
}
}
return m_Enabled;
}
public event EventHandler CanExecuteChanged = delegate { };
public void Execute(object parameter)
{
if (m_Enabled)
m_ExecuteTargets(parameter != null ? parameter.ToString() : null);
}
#endregion
public event Action<string> ExecuteTargets
{
add
{
m_ExecuteTargets += value;
}
remove
{
m_ExecuteTargets -= value;
}
}
public event Func<bool> CanExecuteTargets
{
add
{
m_CanExecuteTargets += value;
CanExecuteChanged(this, EventArgs.Empty);
}
remove
{
m_CanExecuteTargets -= value;
CanExecuteChanged(this, EventArgs.Empty);
}
}
}
//called in ctor where newEvent is defined : StringDelegateCommand newEvent;
private void setNewEventCommand()
{
newEvent = new StringDelegateCommand();
newEvent.CanExecuteTargets += isThereAnotherNewEvent;
newEvent.ExecuteTargets += exacuteNewEvent;
NewEvent = newEvent;
}
void exacuteNewEvent(string message)
{
Window1 w = new Window1();
w.ShowDialog();
}