本文介绍了绑定不会更新用户控件[UWP] [XAML]上的属性的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
你好我有一个UserControl，它只是一个带有一些额外代码的文本框，可以实现模板中我想要的行为。
我的问题是当我绑定时对于ViewModel上的属性，文本框不显示信息。
UserControl的Codebehind
// /< summary>
///包含Float TextBox的文本
///< / summary>
public string Text
{
get {return（string）GetValue（TextProperty）; }
设置
{
SetValue（TextProperty，value）;
NotifyPropertyChanged（" Text"）;
}
}
///< summary>
///用于保存Float TextBox文本的依赖项属性。
///< / summary>
public static readonly DependencyProperty TextProperty =
DependencyProperty.Register（" Text"，typeof（string），typeof（FloatTextBox），null）;
UserControl的XAML文件
< TextBox x：Name =" TextBox"
GotFocus =" TextBox_GotFocus"
LostFocus =" TextBox_LostFocus"
TextChanged =" TextBox_TextChanged"
PointerEntered =" TextBox_PointerEntered"
PointerExited =" TextBox_PointerExited"
PointerPressed =" TextBox_PointerPressed"
PointerReleased =" TextBox_PointerReleased"
PlaceholderText =" {Binding PlaceholderText}"
Header =" {Binding PlaceholderText}"
TextWrapping =" {Binding TextWrapping}"
Text =" {Binding Text，Mode = TwoWay，UpdateSourceTrigger = PropertyChanged}"
IsReadOnly =" {Binding IsReadOnly}"
BorderThickness =" {Binding BorderThickness}"
BorderBrush =" {Binding BorderBrush}"
AcceptsReturn =" {Binding AcceptsReturn}"
MaxLength =" {Binding MaxLength}" />
我正在测试控件的页面
< Page
x：Class =" CustomControlsTestApp.MainPage"
xmlns =" http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns：x =" http://schemas.microsoft.com/winfx/2006/xaml"
xmlns：local =" using：CustomControlsTestApp"
xmlns：d =" http://schemas.microsoft.com/expression/blend/2008"
xmlns：mc =" http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns：customControls =" using：CustomControlLibrary"
mc：Ignorable =" d">
< Grid Background =" AliceBlue">
< StackPanel Orientation =" Vertical">
< TextBlock Text =" PasswordBox"
Margin =" 0,20,0,0" />
< customControls：FloatPasswordBox PlaceholderHeaderText ="密码"
密码="测试" />
< TextBlock Text =" Float TextBox"
Margin =" 0,20,0,0" />
< customControls：FloatTextBox PlaceholderText =" Sample Text" Text =" {Binding TestValue，Mode = TwoWay}" />
< TextBlock Text =" Float TextBox No X"
Margin =" 0,20,0,0" />
< customControls：FloatTextBox PlaceholderText =" Sample Text"
FloatTextMode =" NoX"
InputScopeNameValue =" Number" />
< Button Content =" To Password Overlay"
Click =" Button_Click"
Margin =" 0,20,0,0" />
< Button Content =" Check MyValue"
Click =" Button_Click_1" />
< / StackPanel>
< / Grid>
< / Page>
该页面背后的代码
public密封的分部类MainPage：Page，INotifyPropertyChanged
{
private string _testValue;
public string TestValue
{
get {return _testValue; }
设置
{
if（_testValue！= value）
{
_testValue = value;
NotifyPropertyChanged（nameof（TestValue））;
}
}
}
public MainPage（）
{
this.InitializeComponent（）;
}
protected override void OnNavigatedTo（NavigationEventArgs e）
{
TestValue =" Do Something Please" ;;
base.OnNavigatedTo（e）;
}
private void Button_Click（object sender，RoutedEventArgs e）
{
this.Frame.Navigate（typeof（PasswordOverlayPage））;
}
private async void Button_Click_1（object sender，RoutedEventArgs e）
{
await new MessageDialog（TestValue）.ShowAsync（）;
}
公共事件PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged（string info）
{
PropertyChanged？.Invoke（this，new PropertyChangedEventArgs（info））;
}
}
解决方案
Hello I have a UserControl which is just a textbox with some extra code to achieve the behavior I'd like in the templates.
My issue is that when I bind it to a property on a ViewModel, the textbox does not display the information.
The Codebehind for the UserControl
/// <summary>
/// Contains the Text for the Float TextBox
/// </summary>
public string Text
{
get { return (string)GetValue(TextProperty); }
set
{
SetValue(TextProperty, value);
NotifyPropertyChanged("Text");
}
}
/// <summary>
/// Dependency Property to hold the Text for the Float TextBox.
/// </summary>
public static readonly DependencyProperty TextProperty =
DependencyProperty.Register("Text", typeof(string), typeof(FloatTextBox), null);
The XAML file for the UserControl
<TextBox x:Name="TextBox"
GotFocus="TextBox_GotFocus"
LostFocus="TextBox_LostFocus"
TextChanged="TextBox_TextChanged"
PointerEntered="TextBox_PointerEntered"
PointerExited="TextBox_PointerExited"
PointerPressed="TextBox_PointerPressed"
PointerReleased="TextBox_PointerReleased"
PlaceholderText="{Binding PlaceholderText}"
Header="{Binding PlaceholderText}"
TextWrapping="{Binding TextWrapping}"
Text="{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
IsReadOnly="{Binding IsReadOnly}"
BorderThickness="{Binding BorderThickness}"
BorderBrush="{Binding BorderBrush}"
AcceptsReturn="{Binding AcceptsReturn}"
MaxLength="{Binding MaxLength}"/>
The page I am testing the control on
<Page
x:Class="CustomControlsTestApp.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:CustomControlsTestApp"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:customControls="using:CustomControlLibrary"
mc:Ignorable="d">
<Grid Background="AliceBlue">
<StackPanel Orientation="Vertical">
<TextBlock Text="PasswordBox"
Margin="0,20,0,0"/>
<customControls:FloatPasswordBox PlaceholderHeaderText="Password"
Password="Test"/>
<TextBlock Text="Float TextBox"
Margin="0,20,0,0"/>
<customControls:FloatTextBox PlaceholderText="Sample Text" Text="{Binding TestValue, Mode=TwoWay}"/>
<TextBlock Text="Float TextBox No X"
Margin="0,20,0,0" />
<customControls:FloatTextBox PlaceholderText="Sample Text"
FloatTextMode="NoX"
InputScopeNameValue="Number"/>
<Button Content="To Password Overlay"
Click="Button_Click"
Margin="0,20,0,0" />
<Button Content="Check MyValue"
Click="Button_Click_1" />
</StackPanel>
</Grid>
</Page>
And the code behind for that page
public sealed partial class MainPage : Page, INotifyPropertyChanged
{
private string _testValue;
public string TestValue
{
get { return _testValue; }
set
{
if (_testValue != value)
{
_testValue = value;
NotifyPropertyChanged(nameof(TestValue));
}
}
}
public MainPage()
{
this.InitializeComponent();
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
TestValue = "Do Something Please";
base.OnNavigatedTo(e);
}
private void Button_Click(object sender, RoutedEventArgs e)
{
this.Frame.Navigate(typeof(PasswordOverlayPage));
}
private async void Button_Click_1(object sender, RoutedEventArgs e)
{
await new MessageDialog(TestValue).ShowAsync();
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(string info)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(info));
}
}
解决方案
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