[英]UWP User Control DependencyProperty not working
我正在學習UWP用戶控制並面對以下代碼:
<Page
x:Class="LearningUWP.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:LearningUWP"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<StackPanel>
<local:MyUserControl Username="aaa" Password="bbb" fillcolor="Blue" />
</StackPanel>
</Page>
我已經定義了一個具有三個依賴項屬性的用戶控件,用戶名,密碼和fillcolor。 以下代碼顯示了我的用戶控件xaml
<UserControl
x:Name="myctrl"
x:Class="LearningUWP.MyUserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:LearningUWP"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
>
<RelativePanel>
<Rectangle Fill="{Binding fillcolor, ElementName=myctrl}" x:Name="Rec" Height="100" RelativePanel.AlignRightWithPanel="True" />
<TextBlock Text="Username_lbl" RelativePanel.AlignRightWithPanel="True" TextAlignment="Center" RelativePanel.Below="Rec" x:Name="Username_lb" Margin="0,50,0,0" RelativePanel.AlignLeftWithPanel="True" />
<TextBox x:Name="Username_input" RelativePanel.Below="Username_lb" RelativePanel.AlignRightWithPanel="True" RelativePanel.AlignLeftWithPanel="True" Margin="0,20,0,0" Text="{Binding Username, ElementName=myctrl}" ></TextBox>
<TextBlock Text="Password_lbl" x:Name="Password_lb" RelativePanel.AlignRightWithPanel="True" TextAlignment="Center" RelativePanel.Below="Username_input" RelativePanel.AlignLeftWithPanel="True" Margin="0,20,0,0" ></TextBlock>
<TextBox x:Name="Password_input" RelativePanel.Below="Password_lb" RelativePanel.AlignRightWithPanel="True" RelativePanel.AlignLeftWithPanel="True" Margin="0,20,0,0" Text="{Binding Password, ElementName=myctrl}" ></TextBox>
</RelativePanel>
</UserControl>
和代碼隱藏:
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
namespace LearningUWP
{
public sealed partial class MyUserControl : UserControl
{
public MyUserControl()
{
this.InitializeComponent();
}
public string Username
{
get { return (string)GetValue(UsernameProperty); }
set { SetValue(UsernameProperty, value); }
}
public static readonly DependencyProperty UsernameProperty =
DependencyProperty.Register("Username", typeof(string), typeof(MyUserControl), null);
public string Password
{
get { return (string)GetValue(PasswordProperty); }
set { SetValue(PasswordProperty, value); }
}
public static readonly DependencyProperty PasswordProperty =
DependencyProperty.Register("Password", typeof(string), typeof(MyUserControl), null);
public string fillcolor
{
get { return (string)GetValue(fillcolorProperty); }
set { SetValue(fillcolorProperty, value); }
}
public static readonly DependencyProperty fillcolorProperty =
DependencyProperty.Register("fillcolor", typeof(string), typeof(MyUserControl), null);
}
}
用戶名和密碼正常工作,因為我可以在屏幕上看到“aaa”和“bbb”,但顏色不起作用。 怎么解決?
UPDATE1
我將fillcolor屬性修改為以下代碼:
public Brush fillcolor
{
get { return (Brush)GetValue(fillcolorProperty); }
set { SetValue(fillcolorProperty, value); }
}
public static readonly DependencyProperty fillcolorProperty =
DependencyProperty.Register("fillcolor", typeof(Brush), typeof(MyUserControl), null);
但它仍然無法正常工作。
UPDATE2
我更新了下面顯示的MainPage.xaml:
<Page
x:Class="LearningUWP.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:LearningUWP"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Page.Resources>
<SolidColorBrush x:Key="MyBlueColor" Color="#0000FF"/>
</Page.Resources>
<StackPanel>
<local:MyUserControl Username="aaa" Password="bbb" fillcolor="{StaticResource MyBlueColor}" />
</StackPanel>
</Page>
但它仍然無法正常工作。
您的綁定似乎是正確的,您的問題在'fillcolor'屬性的Type
中。 您將它綁定為字符串,而您應該將其綁定為Brush
public Brush fillcolor
{
get { return (Brush)GetValue(fillcolorProperty); }
set { SetValue(fillcolorProperty, value); }
}
public static readonly DependencyProperty fillcolorProperty =
DependencyProperty.Register("fillcolor", typeof(Brush), typeof(MyUserControl), null);
Fill屬性需要一個Brush才能正常工作,你可以在這里看到Shape.Fill
我忘了提到你不需要在這種情況下指定元素名稱,因為你使用你的代碼作為'ViewModel',所以,下面的代碼將為你做到這一點:
<Rectangle Fill="{x:Bind fillcolor}" x:Name="Rec" Height="100" RelativePanel.AlignRightWithPanel="True" />
此外,您需要在頁面的資源中將Brush
指定為純色畫筆,因此您可以編寫:
<Page
x:Class="LearningUWP.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:LearningUWP"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Page.Resources>
<SolidColorBrush x:Key="MyBlueColor" Color="#0000FF"/> <!-- or Blue -->
</Page.Resources>
<StackPanel>
<local:MyUserControl Username="aaa" Password="bbb" fillcolor="{StaticResource MyBlueColor}" />
</StackPanel>
</Page>
並且,根據綁定與xbind之間的區別我們需要使用x:Bind
Binding不支持框架元素。
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