如何从后面的代码访问xaml中声明的全局变量

时间:2013-04-01 16:41:37

标签: c# wpf xaml resources

我想从wpf中的不同导航页面访问一个对象。为此,我创建了一个类并在app.xaml中声明。我可以从xaml中的多个导航页面访问该类,但是当我想在代码后面创建按钮点击事件时,我无法访问该类。

继承人我做了什么。

该类(SerialComm.cs)。

class SerialComm : INotifyPropertyChanged
{
    private SerialPort _serialPortComm;

    public SerialComm()
    {
        _serialPortComm = new SerialPort();
    }

    public SerialPort SerialPortComm
    {
        get { return _serialPortComm; }
        set
        {
            _serialPortComm = value;
            OnPropertyChanged("SerialPortComm");
        }
    }

    #region NotifyPropertyChange handler
    public event PropertyChangedEventHandler PropertyChanged;

    [NotifyPropertyChangedInvocator]
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
    }
    #endregion

}

资源字典(/Resources/DataSourceResources.xaml)

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                xmlns:sys="clr-namespace:System;assembly=mscorlib" 
                xmlns:local="clr-namespace:RemoteConfigurator"
                xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
                mc:Ignorable="d" 
                >
<local:SerialComm x:Key="SerialCommDataSource" d:IsDataSource="True" />

app.xaml中的声明

<Application x:Class="RemoteConfigurator.App"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:local="clr-namespace:RemoteConfigurator"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         mc:Ignorable="d" 
         StartupUri="MainWindow.xaml">
<Application.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="/Resources/DataSourceResources.xaml"/>
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</Application.Resources>

我可以访问该对象的导航页面。

<UserControl x:Class="RemoteConfigurator.Content.SerialSettings"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         xmlns:ports="clr-namespace:System.IO.Ports;assembly=System"
         xmlns:sys="clr-namespace:System;assembly=mscorlib" 
         xmlns:local="clr-namespace:RemoteConfigurator"
         mc:Ignorable="d" 
         d:DesignHeight="600" d:DesignWidth="600" Loaded="SerialSettings_Loaded">

<Grid Style="{StaticResource ContentRoot}" DataContext="{Binding Source={StaticResource SerialCommDataSource}}" >
    <ScrollViewer>
        <StackPanel >
            <StackPanel Orientation="Horizontal" Margin="4">
                <TextBlock TextWrapping="Wrap" Text="Baud Rate (bps)" VerticalAlignment="Center" MinWidth="150"/>
                <TextBox x:Name="tbbaudRate" Height="23" TextWrapping="Wrap" MinWidth="200" Text="{Binding SerialPortComm.BaudRate}" />
            </StackPanel>
        </StackPanel>
    </ScrollViewer>
    **<Button Content="Connect" HorizontalAlignment="Right" VerticalAlignment="Bottom" Click="Button_Connect"/>**
</Grid>

问题在于我如何从代码后面访问SerialPort?该类实际声明在哪里。 iirc,我从不调用任何串口构造函数。

这里有代码。

        private void Button_Connect(object sender, RoutedEventArgs e)
    {
        **//SerialPortComm - doesnt work**
        **//SerialCommDataSource - doest work**
    }

如何从代码后面访问串口对象?

感谢。

1 个答案:

答案 0 :(得分:3)

你可以做到

App.Current.Resources["SerialCommDataSource"] as SerialCom;

基本上,当您添加了一个包含密钥SerialCommDataSource的全局资源时,您可以像上面那样获得它