在MVVM中使用SaveFileDialog的WPF
我正在努力在MVVM中使用SaveFileDialog 我正在使用RelayCommand类并启动SaveAsFileCommand。在SaveAsFileCommand中,使用lambda表达式,我将两个参数拆分为: RichTextBox控件和目标路径(filePath)的实例 然后我使用上述参数调用DataIO.SaveAsFile(参数[0],参数[1]) 要在视图层中创建保存对话框,我将使用3个类: 对话框,文件对话框和保存文件对话框 在XAML中,我创建了SaveDialogBox,并尝试使用多绑定调用SaveAsFileCommand来传递这两个命令参数 要显示保存对话框,我使用绑定到保存对话框的按钮 问题是:在这里,编译器抱怨它无法为我的SaveDialogBox执行多重绑定,因为它是非DependencyObject和非DependencyProperty。在MVVM中使用SaveFileDialog的WPF,wpf,file,mvvm,dialog,save,Wpf,File,Mvvm,Dialog,Save,我正在努力在MVVM中使用SaveFileDialog 我正在使用RelayCommand类并启动SaveAsFileCommand。在SaveAsFileCommand中,使用lambda表达式,我将两个参数拆分为: RichTextBox控件和目标路径(filePath)的实例 然后我使用上述参数调用DataIO.SaveAsFile(参数[0],参数[1]) 要在视图层中创建保存对话框,我将使用3个类: 对话框,文件对话框和保存文件对话框 在XAML中,我创建了SaveDialogBox,
在我的情况下,如何使用符合MVVM的
对话框解决该问题并正确保存文件
XAML部分代码:
<Button Command="{Binding ElementName=SaveFileDB, Path=Show}" >
<Button.ToolTip>
<ToolTip Style="{StaticResource styleToolTip}" >
<TextBlock Text="Save" Style="{StaticResource styleTextBlockTP}" />
</ToolTip>
</Button.ToolTip>
<Image Source="Icon\Save.png"/>
</Button>
<local:SaveFileDialogBox x:Name="SaveFileDB" Caption="Save content to file..."
Filter="Text files (*.txt)|*.txt|All files(*.*)|*.*"
FilterIndex="0" DefaultExt="txt"
CommandFileOK="{Binding SaveAsFileCommand}" >
<local:SaveFileDialogBox.CommandParemeter>
<MultiBinding Converter="{StaticResource parametersConverter}">
<Binding ElementName="MainRichTextBox" />
<Binding ElementName="SaveFileDB" Path="Show" />
</MultiBinding>
</local:SaveFileDialogBox.CommandParemeter>
</local:SaveFileDialogBox>
DataIO.SaveAsFile方法:
public static void SaveAsFile(object argument0, object argument1)
{
System.Windows.Controls.RichTextBox richTB = argument0 as System.Windows.Controls.RichTextBox;
string path = (string)argument1;
using (FileStream fileStream = new FileStream(path, FileMode.Create))
{
TextRange textRange = new TextRange(richTB.Document.ContentStart, richTB.Document.ContentEnd);
textRange.Save(fileStream, DataFormats.Text);
}
}
中继命令类:
class RelayCommand : ICommand
{
private readonly Action<object> _Execute;
private readonly Func<object, bool> _CanExecute;
public RelayCommand(Action<object> execute, Func<object, bool> canExecute)
{
if (execute == null) throw new ArgumentNullException("execute");
_Execute = execute;
_CanExecute = canExecute;
}
public RelayCommand(Action<object> execute)
{
if (execute == null) throw new ArgumentNullException("execute");
_Execute = execute;
}
public bool CanExecute(object parameter)
{
return _CanExecute == null ? true : _CanExecute(parameter);
}
public event EventHandler CanExecuteChanged
{
add
{
if (_CanExecute != null) CommandManager.RequerySuggested += value;
}
remove
{
if (_CanExecute != null) CommandManager.RequerySuggested -= value;
}
}
public void Execute(object parameter)
{
_Execute(parameter);
}
}
SaveFileDialogBox类:
public abstract class DialogBox : FrameworkElement, INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected void OnPropertyChanged(string parameter)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(parameter));
}
protected Action<object> execute = null;
public string Caption { get; set; }
protected ICommand show;
public virtual ICommand Show
{
get
{
if (show == null)
show = new RelayCommand(execute);
return show;
}
}
}
public abstract class FileDialogBox : CommandDialogBox
{
public bool? FileDialogResult { get; protected set; }
public string FilePath { get; set; }
public string Filter { get; set; }
public int FilterIndex { get; set; }
public string DefaultExt { get; set; }
protected Microsoft.Win32.FileDialog fileDialog = null;
protected FileDialogBox()
{
execute =
o =>
{
var values = (object[])o;
RelayCommand relCom1 = (RelayCommand)values[1];
fileDialog.Title = Caption;
fileDialog.Filter = Filter;
fileDialog.FilterIndex = FilterIndex;
fileDialog.DefaultExt = DefaultExt;
string filePath = "";
if (FilePath != null) filePath = FilePath; else FilePath = "";
//if (o != null) filePath = (string)o;
//if (o != null) filePath = (string)values[1];
if (o != null) filePath = relCom1.ToString();
if (!String.IsNullOrWhiteSpace(filePath))
{
fileDialog.InitialDirectory = System.IO.Path.GetDirectoryName(filePath);
fileDialog.FileName = System.IO.Path.GetFileName(filePath);
}
FileDialogResult = fileDialog.ShowDialog();
OnPropertyChanged("FileDialogResult");
if (FileDialogResult.HasValue && FileDialogResult != null)
{
FilePath = fileDialog.FileName;
OnPropertyChanged("FilePath");
ExecuteCommand(CommandFileOK, FilePath);
};
};
}
public static DependencyProperty CommandFileOKProperty =
DependencyProperty.Register("CommandFileOK", typeof(ICommand), typeof(FileDialogBox));
public ICommand CommandFileOK
{
get { return (ICommand)GetValue(CommandFileOKProperty); }
set { SetValue(CommandFileOKProperty, value); }
}
}
public class SaveFileDialogBox : FileDialogBox
{
public SaveFileDialogBox()
{
fileDialog = new SaveFileDialog();
}
}
我在对话框中处理用户输入需求的方法是使用一个进入视图但没有UI的控件。
我将要执行的命令分为两部分。
基本上,它们是显示对话框并在完成时调用命令。
控件显示一个对话框,该对话框获取数据,然后调用通过绑定给它的命令。
由于这是一个控件,您可以很好地绑定它,并且它位于可视化树中,因此它可以获取对窗口的引用
请参见以下内容中的确认请求者:
这是为了确认删除记录,但同样的原则也可以扩展到文件选择器,只需稍加修改
因此,用户单击并关闭对话框后调用的命令可以捕获所需的任何变量。如果您绑定它们:
private RelayCommand _confirmCommand;
public RelayCommand ConfirmCommand
{
get
{
return _confirmCommand
?? (_confirmCommand = new RelayCommand(
() =>
{
confirmer.Caption = "Please Confirm";
confirmer.Message = "Are you SURE you want to delete this record?";
confirmer.MsgBoxButton = MessageBoxButton.YesNo;
confirmer.MsgBoxImage = MessageBoxImage.Warning;
OkCommand = new RelayCommand(
() =>
{
// You would do some actual deletion or something here
UserNotificationMessage msg = new UserNotificationMessage { Message = "OK.\rDeleted it.\rYour data is consigned to oblivion.", SecondsToShow = 5 };
Messenger.Default.Send<UserNotificationMessage>(msg);
});
RaisePropertyChanged("OkCommand");
ShowConfirmation = true;
}));
}
}
我假设您希望自己实现这些对话框?因为如果您对内置系统对话框感到满意,并且仍然对MVVM友好,那么总会有MVVM对话框供您使用。在这种情况下,我需要实现内置对话框(完全是来自Microsoft.Win32命名空间的对话框),但我想从视图层调用它们,而不是从ViewModel或Model调用它们-这会导致问题
private RelayCommand _confirmCommand;
public RelayCommand ConfirmCommand
{
get
{
return _confirmCommand
?? (_confirmCommand = new RelayCommand(
() =>
{
confirmer.Caption = "Please Confirm";
confirmer.Message = "Are you SURE you want to delete this record?";
confirmer.MsgBoxButton = MessageBoxButton.YesNo;
confirmer.MsgBoxImage = MessageBoxImage.Warning;
OkCommand = new RelayCommand(
() =>
{
// You would do some actual deletion or something here
UserNotificationMessage msg = new UserNotificationMessage { Message = "OK.\rDeleted it.\rYour data is consigned to oblivion.", SecondsToShow = 5 };
Messenger.Default.Send<UserNotificationMessage>(msg);
});
RaisePropertyChanged("OkCommand");
ShowConfirmation = true;
}));
}
}
public static readonly DependencyProperty ShowConfirmDialogProperty =
DependencyProperty.Register("ShowConfirmDialog",
typeof(bool?),
typeof(ConfirmationRequestor),
new FrameworkPropertyMetadata(null
, new PropertyChangedCallback(ConfirmDialogChanged)
)
{ BindsTwoWayByDefault = true }
);
private static void ConfirmDialogChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if ((bool?)e.NewValue != true)
{
return;
}
ConfirmationRequestor cr = (ConfirmationRequestor)d;
Window parent = Window.GetWindow(cr) as Window;
MessageBoxResult result = MessageBox.Show(parent, cr.Message, cr.Caption, cr.MsgBoxButton, cr.MsgBoxImage);
if (result == MessageBoxResult.OK || result == MessageBoxResult.Yes)
{
if (cr.Command != null)
{
cr.Command.Execute(cr.CommandParameter);
}
}
cr.SetValue(ShowConfirmDialogProperty, false);
}