如何在窗口電話中將參數傳遞給usercontrol？

Question

我創建了一個用戶控件WPF：

<UserControl 
x:Class="BARCIndia.Mobile.Views.UserControls.SubCategoryUserControl" 
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
xmlns:local="using:BARCIndia.Mobile.Views.UserControls" 
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 Background="DarkCyan">     
    <TextBlock Name="txtName" FontSize="26"></TextBlock> 
    </StackPanel> 
    </Grid>   
</UserControl> 

的代碼背後有一個叫財產「ParamValue」它設置爲我的用戶控制TextBlock:txtName

public sealed partial class SubCategoryUserControl : UserControl 
    {   
     public string ParamValue 
     { 
     get { return (string)GetValue(ParamValueProperty); } 
     set { SetValue(ParamValueProperty, value); } 
     }   
     public static readonly DependencyProperty ParamValueProperty = DependencyProperty.Register 
     (
     "ParamValue", 
     typeof(string), 
     typeof(SubCategoryUserControl), 
     new PropertyMetadata(string.Empty) 
    ); 

    public SubCategoryUserControl() 
    { 
    this.InitializeComponent(); 
    txtName.Text = this.ParamValue; 
    }   
    } 

的文本從XAML調用形式

<Grid > 

<Grid.RowDefinitions> 
<RowDefinition></RowDefinition> 
</Grid.RowDefinitions> 

<Myusercontrol:SubCategoryUserControl x:Name="tempUserControl" ParamValue="From Window" Grid.Row="0"/> 

</Grid> 

這裏我有通參數ParamValue = 「從窗口」當usercontrol加載的文本塊顯示爲空時。

屬性沒有得到更新，同時創造扶養財產

public static readonly DependencyProperty ParamValueProperty = DependencyProperty.Register 
      (
       "ParamValue", 
       typeof(string), 
       typeof(SubCategoryUserControl), 
       **new PropertyMetadata(string.Empty)** 
      ); 

我得到如何分配的值賦予它的表現emtry串即默認值？

Answer 1

在你的情況可能是這樣的：

public sealed partial class SubCategoryUserControl : UserControl 
{ 
    public string ParamValue 
    { 
     get 
     { 
      return (string) GetValue(ParamValueProperty); 
     } 
     set 
     { 
      SetValue(ParamValueProperty, value); 
     } 
    } 

    public static readonly DependencyProperty ParamValueProperty = DependencyProperty.Register 
     (
      "ParamValue", 
      typeof (string), 
      typeof (SubCategoryUserControl), 
      new PropertyMetadata(string.Empty) 
     ); 

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

和XAML：

<UserControl x:Class="BARCIndia.Mobile.Views.UserControls.SubCategoryUserControl" 
      x:Name="Root" 
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
      xmlns:local="using:BARCIndia.Mobile.Views.UserControls" 
      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 Background="DarkCyan">     
    <TextBlock Text="{Binding ParamValue, ElementName=Root}" FontSize="26" /> 
    </StackPanel> 
    </Grid>   
</UserControl>