如何检查列表中的可用频道<>

Question

我是C ++开发人员，最近转移到了C＃。 我正在使用wpf应用程序，必须动态生成按钮，标签和文本框。 除了动态生成它们之外，我还通过维护bool available属性来确保仅显示那些可用的通道。 这是代码：

XAML：

<Grid Visibility="{Binding IsAvailable, Converter={StaticResource booltovisibility}}">          

    <Label Grid.Column="0" Content="{Binding ChannelName}" />
    <TextBox Grid.Column="1" Text="{Binding VoltageText}" PreviewTextInput="VoltageBox_PreviewTextInput"  />
    <Button Grid.Column="1" Content="Set" CommandParameter="{Binding}" Command="{Binding VoltageCommand}" />
    <Label Grid.Column="2" Content="{Binding CurrentText}" />
    <ToggleButton Grid.Column="3" Content="On" Command="{Binding VoltageToggleCommand}" IsChecked="{Binding Path=IsChecked}" />
</Grid>

    <Button Content="Refresh All" Grid.Column="1" Command="{Binding Path=RefreshAllButtonCommand}" Name="RefreshAllBtn" />

ViewModel：

public ObservableCollection<VoltageBoardChannel> channelList = null;
public ObservableCollection<VoltageBoardChannel> bavaria1Channels = new ObservableCollection<VoltageBoardChannel>
    {
         new VoltageBoardChannel { ChannelName = "VDD__MAIN", IsAvailable = true, ID = 1},
         new VoltageBoardChannel { ChannelName = "VDD__IO", IsAvailable = true, ID = 2},
         new VoltageBoardChannel { ChannelName = "VDD__CODEC", IsAvailable = true, ID = 3},
         new VoltageBoardChannel { ChannelName = "VDD__LDO", IsAvailable = true, ID = 4},
         new VoltageBoardChannel { ChannelName = "VDD__AMP", IsAvailable = true, ID = 5},   
         new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 6}, 
         new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 7}, 
         new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 8}, 
         new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 9}, 
         new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 10}, 
         new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 11}, 
         new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 12}, 
    };        

    public VoltageViewModel()
    {
        channelList = new ObservableCollection<VoltageBoardChannel>();
        channelList = bavaria1Channels;         

    }
public ObservableCollection<VoltageBoardChannel> VoltageChannelList
    {
        get 
        { 
            return channelList; 
        }

        set
        { 
            channelList = value;
            OnPropertyChanged("ChannelList");
        }
    }

void RefreshAllClick()
{
    //Here I want to check if channel are available or not. If yes then execute few statements.
}

型号类别：

private string mChannelName;
    public string ChannelName
    {
        get
        {
            return mChannelName;
        }
        set
        {
            mChannelName = value;
            OnPropertyChanged("ChannelName");
        }
    }

    private bool mIsAvailable;
    public bool IsAvailable
    {
        get
        {
            return mIsAvailable;
        }
        set
        {
            mIsAvailable = value;
            OnPropertyChanged("IsAvailable");
        }
    }

    double voltageText;
    public double VoltageText
    {
        get
        {
            return voltageText;
        }

        set
        {
            if (value > 5.0D || value < 0.0D)
                throw new InvalidOperationException();
            voltageText = value;
            OnPropertyChanged("VoltageText");
        }
    }

    string currentText = "0";
    public string CurrentText
    {
        get
        {
            return currentText + " V";                
        }

        set
        {
            currentText = value;
            OnPropertyChanged("CurrentText");
        }
    }          

    int index ;
    public int ID
    {
        get
        {
            return index;
        }

        set
        {
            index = value;
            OnPropertyChanged("ID");
        }
    }

因此，如果您在我的Bavaria1 Channel注意到，您会发现很少有可用频道（true），而很少有错误频道。 因此，在启动时，它仅显示可用通道。 因此，使用booltovisibility类，我可以在网格中设置可见性并相应地显示现在，这是我想要实现的目标：

当我单击RefreshAll Button时，将触发一个名为RefreshAll_Click()的方法，我想检查if有条件可用的通道。 如果是，则执行一些语句。 我在C ++中做到了如下：

if(m_voltageChannels[channel].available) // Here channel is 12 as you can notice in bavaria1 list
{
    cmd = (0x8400 | (channel & 0xFF));  

    String OldValue = m_labelCurrentVoltage[channel]->getText();
            //Some Code
    }

我该如何实现？ :)

Answer 1

我会使用foreach循环或linq。 由于您是从C＃开始的，因此这里是foreach方法：

void RefreshAllClick() 
{
    foreach (var channel in channelList)
        if (channel.IsAvailable)
            //some code here 
} 

或者，由于ObservableCollection<T>实现了IList<T> ，因此可以像在C ++代码中一样索引到集合中：

if (channelList[channel].IsAvailable)
    //some code here

如果只需要一个布尔值，并且至少有一个通道可用，则最好使用linq：

var anyChannelIsAvailable = channelList.Any(c => c.IsAvailable);

从我之前的评论（现已删除）中移出，这是一些未经请求的进一步建议：

您应删除channelList = new ObservableCollection<VoltageBoardChannel>(); ，因为您要通过在下一行中重新分配引用来立即丢弃该对象（ channelList = bavaria1Channels; ）。 实际上，您根本不需要bavaria1Channels （也不需要构造函数）。 您可以使用集合初始值设定项表达式声明和初始化channelList ，如下所示：

public ObservableCollection<VoltageBoardChannel> channelList = new ObservableCollection<VoltageBoardChannel>    
{    
     new VoltageBoardChannel { ChannelName = "VDD__MAIN", IsAvailable = true, ID = 1},    
     new VoltageBoardChannel { ChannelName = "VDD__IO", IsAvailable = true, ID = 2},    
     new VoltageBoardChannel { ChannelName = "VDD__CODEC", IsAvailable = true, ID = 3},    
     new VoltageBoardChannel { ChannelName = "VDD__LDO", IsAvailable = true, ID = 4},    
     new VoltageBoardChannel { ChannelName = "VDD__AMP", IsAvailable = true, ID = 5},       
     new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 6},     
     new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 7},     
     new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 8},     
     new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 9},     
     new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 10},     
     new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 11},     
     new VoltageBoardChannel { ChannelName = "", IsAvailable = false, ID = 12},     
};            

Answer 2

if (bavaria1Channels.Any(c => c.IsAvailable)) //Any channel available
{
    //Execute some code :)
}