Question

我有一个WPF应用程序，在一段时间过去之前不允许我单击按钮，但这种行为是随机的，只会在某些时候发生。大部分时间窗口呈现，我可以立即点击所述按钮。

主窗口：

    <views:StatusBox DockPanel.Dock="Left" Visibility="{Binding Editing, Converter={StaticResource BoolToVisibleConverter}}" />
</DockPanel>

用户控制：

<StackPanel Orientation="Horizontal">
    <!--Read Button-->
    <Button Content="Read "   x:Name="ReadBtn"     Command="{Binding ReadCMD}"    Padding="10,5" Margin= "10,0" IsEnabled="{Binding ReadEnabled}" />

    <!--Save Button-->
    <Button Content="Save "   x:Name="SaveBtn"     Command="{Binding SaveCMD}"    Padding="10,5" Margin= "10,0" IsEnabled="{Binding SaveEnabled}" 
            Background="{StaticResource {x:Static SystemColors.ControlLightBrushKey}}">
        <Button.Style>
            <Style TargetType="Button">
                <Style.Triggers>
                    <DataTrigger Binding="{Binding IsSaveNeeded}" Value="Yes">
                        <DataTrigger.EnterActions>
                            <BeginStoryboard x:Name="FlashBackground">
                                <Storyboard BeginTime="00:00:00" RepeatBehavior="Forever" >
                                    <ColorAnimation  Storyboard.TargetProperty="Background.Color" Duration="00:00:00.25" AutoReverse="True" To="Red" />
                                </Storyboard>
                            </BeginStoryboard>
                        </DataTrigger.EnterActions>

                        <DataTrigger.ExitActions>
                            <StopStoryboard BeginStoryboardName="FlashBackground" />
                        </DataTrigger.ExitActions>
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </Button.Style>
    </Button>

    <!--Load Button-->
    <Button Content="Load "   x:Name="LoadBtn"     Command="{Binding LoadCMD}"    Padding="10,5" Margin= "10,0" IsEnabled="{Binding LoadEnabled}" />

    <!--Print Button-->
    <Button Content="Print"   x:Name="PrintBtn"    Command="{Binding PrintCMD}"   Padding="10,5" Margin= "10,0" IsEnabled="{Binding PrintEnabled}" />

    <!--Exit Button-->
    <Button Content="Exit"    x:Name="ExitBtn"     Command="{Binding ExitCMD}"    Padding="10,5" Margin= "10,0" />
</StackPanel>

查看模型

private bool _tab1_Selected;
    public bool tab1_Selected
    {
        get
        {
            return _tab1_Selected;
        }
        set
        {
            _tab1_Selected = value;

            if (value)
            {
                CommMode = (byte)PacketType.tab1_DUMP;

                if (tab1needsSaving)
                {
                    IsSaveNeeded = SaveNeeded.Yes;
                }
                else
                {
                    IsSaveNeeded = SaveNeeded.No;
                }
            }

            NotifyPropertyChanged("tab1_Selected");
            NotifyPropertyChanged("SaveEnabled");
            NotifyPropertyChanged("ProgramEnabled");
            NotifyPropertyChanged("Editing");
        }
    }


    private bool _tab2_Selected;
    public bool tab2_Selected
    {
        get
        {
            return _tab2_Selected;
        }
        set
        {
            _tab2_Selected = value;

            if (value)
            {
                CommMode = (byte)PacketType.tab2_DUMP;

                if (tab2needsSaving)
                {
                    IsSaveNeeded = SaveNeeded.Yes;
                }
                else
                {
                    IsSaveNeeded = SaveNeeded.No;
                }
            }

            NotifyPropertyChanged("tab2_Selected");
            NotifyPropertyChanged("SaveEnabled");
            NotifyPropertyChanged("ProgramEnabled");
            NotifyPropertyChanged("Editing");
        }
    }


public bool Editing
    {
        get
        {
            return tab2_Selected || tab1_Selected;
        }
    }

 private bool _saveEnabled;
    public bool SaveEnabled
    {
        get
        {
            //return _saveEnabled;
            return ((tab1_Selected && tab1Data != null && tab1Data.Count > 0) || (tab2_Selected && tab2Data != null && tab2Data.Count > 0) && _saveEnabled);
        }
        set
        {
            _saveEnabled = value;
            NotifyPropertyChanged("SaveEnabled");
        }
    }

 private bool _programEnabled;
    public bool ProgramEnabled
    {
        get
        {
            //return _saveEnabled;
            return ((tab1_Selected && tab1Data != null && tab1Data.Count > 0) || (tab2_Selected && tab2Data != null && tab2Data.Count > 0) && _programEnabled);
        }
        set
        {
            _programEnabled = value;
            NotifyPropertyChanged("ProgramEnabled");
        }
    }

命令：

    public ICommand ReadCMD     { get; set; }
    public ICommand SaveCMD     { get; set; }
    public ICommand LoadCMD     { get; set; }
    public ICommand ProgramCMD  { get; set; }
    public ICommand PrintCMD    { get; set; }
    public ICommand ExitCMD     { get; set; }

    // In MainVM constructor
    ReadCMD = new RelayCommand(ReadSettings);
    SaveCMD = new RelayCommand(SaveSettings);
    LoadCMD = new RelayCommand(LoadSettings);
    ProgramCMD = new RelayCommand(ProgramSettings);
    PrintCMD = new RelayCommand(PrintSettings);
    ExitCMD = new RelayCommand(ExitProgram);

中继命令类：

 public class RelayCommand : ICommand
{
    private Action<object> execute;

    private Predicate<object> canExecute;

    private event EventHandler CanExecuteChangedInternal;

    public RelayCommand(Action<object> execute)
        : this(execute, DefaultCanExecute)
    {
    }

    public RelayCommand(Action<object> execute, Predicate<object> canExecute)
    {
        if (execute == null)
        {
            throw new ArgumentNullException("execute");
        }

        if (canExecute == null)
        {
            throw new ArgumentNullException("canExecute");
        }

        this.execute = execute;
        this.canExecute = canExecute;
    }

    public event EventHandler CanExecuteChanged
    {
        add
        {
            CommandManager.RequerySuggested += value;
            this.CanExecuteChangedInternal += value;
        }

        remove
        {
            CommandManager.RequerySuggested -= value;
            this.CanExecuteChangedInternal -= value;
        }
    }

    public bool CanExecute(object parameter)
    {
        return this.canExecute != null && this.canExecute(parameter);
    }

    public void Execute(object parameter)
    {
        this.execute(parameter);
    }

    public void OnCanExecuteChanged()
    {
        EventHandler handler = this.CanExecuteChangedInternal;
        if (handler != null)
        {
            //DispatcherHelper.BeginInvokeOnUIThread(() => handler.Invoke(this, EventArgs.Empty));
            handler.Invoke(this, EventArgs.Empty);
        }
    }

    public void Destroy()
    {
        this.canExecute = _ => false;
        this.execute = _ => { return; };
    }

    private static bool DefaultCanExecute(object parameter)
    {
        return true;
    }
}

更新

我从DockPanel切换到StackPanel并将宽度设置为StatusBox，而不是让LastChildFill调整状态字段，这解决了我的问题。即使我在StatusBox周围放置一个边框来查看它所呈现的位置，但它仍然给了我一些问题。

Answer 1

根据是否可以执行命令，您无需明确绑定到SaveEnabled属性以使按钮被禁用/启用。只需在RelayCommand的谓词中包含CanExecute逻辑，如果属性发生更改，请在命令上调用OnCanExecuteChanged以启用该按钮。

修改

像这样的东西

<Button Content="Save" x:Name="SaveBtn" Command="{Binding SaveCMD}" Padding="10,5" Margin= "10,0"/>

然后在你看来你应该能够使用它，它应该有效：

Private Sub CommandButton3_Click() Dim VectorGrafica(26) As Integer Dim cuenta As Integer Dim ho As Integer Dim ma As Integer Dim ejex As Range Dim numero As Integer Dim ejey As Range cuenta = 0 da = 1 If ComboBox3 = "" Or ComboBox4 = "" Then MsgBox "No ha determinado el horizonte de tiempo", vbOKOnly, "Horizonte de tiempo" End If For s = 24 To 46 If Controls("CheckBox" & s) = True Then cuenta = 1 + cuenta VectorGrafica(da) = 1 da = da + 1 Else VectorGrafica(da) = 0 da = da + 1 End If Next s If cuenta = 0 Then MsgBox "No ha seleccionado ningún rubro", vbOKOnly, "Rubros" End If If cuenta > 0 Then numero = 1 Select Case ComboBox3.ListIndex Case 0 ma = 2 Case 1 ma = 3 Case 2 ma = 4 Case 3 ma = 5 Case 4 ma = 6 Case 5 ma = 7 Case 6 ma = 8 Case 7 ma = 9 Case 8 ma = 10 Case 9 ma = 11 Case 10 ma = 12 Case 11 ma = 13 End Select Select Case ComboBox4.ListIndex Case 0 ho = 2 Case 1 ho = 3 Case 2 pa = 4 Case 3 ho = 5 Case 4 ho = 6 Case 5 ho = 7 Case 6 ho = 8 Case 7 ho = 9 Case 8 ho = 10 Case 9 ho = 11 Case 10 ho = 12 Case 11 ho = 13 End Select Dim hola As Range ActiveSheet.Shapes.AddChart2(240, xlXYScatterSmooth).Select For i = 1 To 25 If VectorGrafica(i) = 1 Then ActiveChart.Activate Set rangodenombre = Sheets(ComboBox6.Text).Cells(i + 1, 1) ActiveChart.SeriesCollection.NewSeries ActiveChart.FullSeriesCollection(numero).Name = rangodenombre ActiveChart.SeriesCollection(numero).XValues = _Sheets(ComboBox6.Text).Range(Cells(1, ma), Cells(1, ho)) ActiveChart.SeriesCollection(numero).Values = Sheets(ComboBox6.Text).Range(Cells(i + 1, ma), Cells(1 + i, ho))*** numero = numero + 1 End If Next i End If End Sub

渲染Window时按钮不可点击

1 个答案: