Question

我正在使用通用应用程序（Windows 8.1）。

我想通过点击UserControl中的按钮来增加主页中的“Number”属性。

（上面的代码就是一个例子）

Mainpage.xaml：

<Page
    x:Class="App3.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:App3"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    xmlns:uc="using:App3"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <Grid>
        <uc:MyUserControl1></uc:MyUserControl1>
    </Grid>
</Page>

Mainpage.xaml.cs：

namespace App3
{
    public sealed partial class MainPage : Page
    {
        public int number { get; set; }

        public MainPage()
        {
            this.InitializeComponent();

            this.NavigationCacheMode = NavigationCacheMode.Required;
        }

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
        }
    }
}

MyUserControl1.xaml

<UserControl
    x:Class="App3.MyUserControl1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:App3"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300"
    d:DesignWidth="400">

    <Grid>
        <StackPanel>
        <TextBlock Text="Test" />
        <TextBlock Text="Test" />
        <TextBlock Text="Test" />
        <Button Height="20"
                Width="50"
                Content="click"
                Click="Button_Click"/>
            <TextBlock Text="Test" />
            <TextBlock Text="Test" />
            <TextBlock Text="Test" />
        </StackPanel>
    </Grid>
</UserControl>

MyUserControl1.xaml.cs

namespace App3
{
    public sealed partial class MyUserControl1 : UserControl
    {
        public MyUserControl1()
        {
            this.InitializeComponent();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            //TODO : ?
        }
    }
}

我该怎么办？我不想在app.cs中使用属性......

Answer 1

在Usercontrol中创建一个事件，如下所示：

namespace App3
{
public sealed partial class MyUserControl1 : UserControl
{
    public event EventHandler ButtonClicked;

    public MyUserControl1()
    {
        this.InitializeComponent();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        //TODO : ?
        if (ButtonClicked != null)
            ButtonClicked(this, new EventArgs());
    }
}
}

然后在你的XAML中为MainPage设置一个用户控件中的ButtonClicked事件的事件处理程序，如此

<uc:MyUserControl1 ButtonClicked="Increment_Click"></uc:MyUserControl1>

然后在代码Behind for MainPage中创建Increment_Click方法：

private void Increment_Click(Object sender, RoutedEventArgs e)
{
    number++;
}

Answer 2

在usercontrol中定义一个Dependency属性，并使用依赖属性将此属性绑定到MainPage.by中的一个属性，usercontrol就像一个独立的控件一样，就像一些Button Control等。它将给你一个如何使用DependencyProperty的例子太

在您的usercontrol中添加此代码

public sealed partial class MyUserControl1 : UserControl
{
    public MyUserControl1()
    {
        this.InitializeComponent();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        //TODO : ?
       Caption = 2;
    }

    public int Caption
    {
         get { return (int)GetValue(CaptionProperty); }
            set { SetValue(CaptionProperty, value); }
    }

    public static readonly DependencyProperty CaptionProperty =
            DependencyProperty.Register("Caption", typeof(int), typeof(MyUserControl1),
            new PropertyMetadata(0, null));

}

在你的MainPage.xaml中绑定这个标题属性。

 <Grid>
    <uc:MyUserControl1 Caption="{Binding SomeValue,Mode=TwoWay}" ></uc:MyUserControl1>
</Grid>

将属性添加到MainPage.Xaml.cs中。

public sealed partial class MainPage : Page
{
    public MainPage()
    {
        this.InitializeComponent();
        this.DataContext = this;
    }

    public string SomeValue
    {
        set
        {
            string df = value; // put a break point here and check
        }
    }
}

Now put a break point on Set and see if is it changing or not.

UserControl与Windows 8.1上的父页面进行通信

2 个答案: