在UWP中使用正常的write.xlsx(x, file = "myfile.xlsx", sheetName = "Sheet1", append = FALSE)，您可以数据绑定到TextBox属性，并轻松地从ViewModel获取或设置值。 RichEditBox虽然没有数据绑定Text属性;相反，您必须使用Text属性公开的ITextDocument interface并使用各种方法来获取和设置文本。
如何将纯文本数据绑定到ViewModel中的某些内容？
答案 0 :(得分：4)
可以使用自定义attached property对Document的纯文本进行数据绑定。此附加属性处理富文本和文档纯文本之间的转换。
以下是一个示例XAML页面，代码隐藏和ViewModel，显示了附加属性的用法：
将其复制为项目中新页面的内容
RichEditBox这假设您使用的是默认<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<StackPanel Margin="30">
<RichEditBox local:RichEditBoxExtension.PlainText="{Binding PlainText,
Mode=TwoWay}" x:Name="richedit"/>
<Button Content="Bold selection" Click="MakeBold"/>
<Button Content="Change plain text (view model)" Click="ChangeText"/>
<Button Content="Change rich text (control property)" Click="ChangeRichText"/>
<TextBlock Text="PlainText property is..." />
<TextBlock Text="{Binding PlainText, Mode=OneWay}" />
</StackPanel>
</Grid>
;根据需要更改构造函数名称
MainPage.xaml.cs没什么特别的;只是一个字符串属性。您可以将其放在自己的文件中，或将其粘贴到主代码隐藏文件中。
public MainPage()
{
InitializeComponent();
DataContext = model = new ViewModel();
model.PlainText = "Hello, world";
}
private void ChangeText(object sender, RoutedEventArgs e)
{
model.PlainText = "Here is some plain text";
}
private void ChangeRichText(object sender, RoutedEventArgs e)
{
richedit.Document.SetText(TextSetOptions.None, "Here is some rich text");
var selection = richedit.Document.Selection;
selection.StartPosition = 8;
selection.EndPosition = 12;
selection.CharacterFormat.Underline = UnderlineType.Single;
selection.MoveStart(TextRangeUnit.Word, 1);
selection.Expand(TextRangeUnit.Word);
selection.CharacterFormat.Weight = FontWeights.Bold.Weight;
}
private void MakeBold(object sender, RoutedEventArgs e)
{
richedit.Document.Selection.CharacterFormat.Weight = FontWeights.Bold.Weight;
}
到目前为止，没什么特别的。 public class ViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
string plainText;
public string PlainText
{
get { return plainText; }
set
{
plainText = value;
RaisePropertyChanged();
}
}
void RaisePropertyChanged([CallerMemberName] string propertyName = "")
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
使用附加属性RichEditBox并将其绑定到ViewModel属性RichEditBoxExtension.PlainText。页面上还有另一个PlainText来显示TextBlock属性的当前值，以及一些操作文本的按钮。
PlainText的实现非常简单，但由于依赖属性基础结构和避免无限属性更新的需要（需要更改富文本触发纯文本），因此需要相当多的代码，它会触发触发纯文本的富文本，依此类推）。
这可以在自己的文件中，也可以再次粘贴到代码隐藏文件中。
RichEditBoxExtension.PlainText附加属性基本上做了两件事，但是有很多样板代码和状态机器围绕它：
public class RichEditBoxExtension
{
// Standard attached property. It mimics the "Text" property of normal text boxes
public static readonly DependencyProperty PlainTextProperty =
DependencyProperty.RegisterAttached("PlainText", typeof(string),
typeof(RichEditBoxExtension), new PropertyMetadata(null, OnPlainTextChanged));
// Standard DP infrastructure
public static string GetPlainText(DependencyObject o)
{
return o.GetValue(PlainTextProperty) as string;
}
// Standard DP infrastructure
public static void SetPlainText(DependencyObject o, string s)
{
o.SetValue(PlainTextProperty, s);
}
private static void OnPlainTextChanged(DependencyObject o,
DependencyPropertyChangedEventArgs e)
{
var source = o as RichEditBox;
if (o == null || e.NewValue == null)
return;
// This attaches an event handler for the TextChange event in the RichEditBox,
// ensuring that we're made aware of any changes
AttachRichEditBoxChangingHelper(o);
// To avoid endless property updates, we make sure we only change the RichText's
// Document if the PlainText was modified (vs. if PlainText is responding to
// Document being modified)
var state = GetState(o);
switch (state)
{
case RichEditChangeState.Idle:
var text = e.NewValue as string;
SetState(o, RichEditChangeState.PlainTextChanged);
source.Document.SetText(Windows.UI.Text.TextSetOptions.None, text);
break;
case RichEditChangeState.RichTextChanged:
SetState(o, RichEditChangeState.Idle);
break;
default:
Debug.Assert(false, "Unknown state");
SetState(o, RichEditChangeState.Idle);
break;
}
}
#region Glue
// Trivial state machine to determine who last changed the text properties
enum RichEditChangeState
{
Idle,
RichTextChanged,
PlainTextChanged,
Unknown
}
// Helper class that just stores a state inside a textbox, determining
// whether it is already being changed by code or not
class RichEditChangeStateHelper
{
public RichEditChangeState State { get; set; }
}
// Private attached property (never seen in XAML or anywhere else) to attach
// the state variable for us. Because this isn't used in XAML, we don't need
// the normal GetXXX and SetXXX static methods.
static readonly DependencyProperty RichEditChangeStateHelperProperty =
DependencyProperty.RegisterAttached("RichEditChangeStateHelper",
typeof(RichEditChangeStateHelper), typeof(RichEditBoxExtension), null);
// Inject our state into the textbox, and also attach an event-handler
// for the TextChanged event.
static void AttachRichEditBoxChangingHelper(DependencyObject o)
{
if (o.GetValue(RichEditChangeStateHelperProperty) != null)
return;
var richEdit = o as RichEditBox;
var helper = new RichEditChangeStateHelper();
o.SetValue(RichEditChangeStateHelperProperty, helper);
richEdit.TextChanged += (sender, args) =>
{
// To avoid re-entrancy, make sure we're not already changing
var state = GetState(o);
switch (state)
{
case RichEditChangeState.Idle:
string text = null;
richEdit.Document.GetText(Windows.UI.Text.TextGetOptions.None, out text);
if (text != GetPlainText(o))
{
SetState(o, RichEditChangeState.RichTextChanged);
o.SetValue(PlainTextProperty, text);
}
break;
case RichEditChangeState.PlainTextChanged:
SetState(o, RichEditChangeState.Idle);
break;
default:
Debug.Assert(false, "Unknown state");
SetState(o, RichEditChangeState.Idle);
break;
}
};
}
// Helper to set the state managed by the textbox
static void SetState(DependencyObject o, RichEditChangeState state)
{
(o.GetValue(RichEditChangeStateHelperProperty)
as RichEditChangeStateHelper).State = state;
}
// Helper to get the state managed by the textbox
static RichEditChangeState GetState(DependencyObject o)
{
return (o.GetValue(RichEditChangeStateHelperProperty)
as RichEditChangeStateHelper).State;
}
#endregion
}
附加属性发生更改时，它会使用PlainText RichEditBox
source.Document.SetText(TextSetOptions.None, text)文字发生变化（包括富文本更改）时，它会使用RichEditBox然后PlainText更新richEdit.Document.GetText(TextGetOptions.None, out text)附加属性。请注意，此基本方法可用于数据绑定您希望根据实际数据绑定属性计算的其他“派生”属性。