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我是一名 C++ 开发人员，最近转向 C#。我正在开发一个 wpf 应用程序，我必须在其中动态生成按钮、标签和文本框。除了动态生成它们之外，我还确保只显示那些通过维护 bool 可用属性而可用的通道。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" />

视图模型：

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：

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，如果您在我的文章中注意到，Bavaria1 Channel您会发现可用的频道很少（真），而且很少有假的。因此在启动时它只显示可用的频道。因此，使用 booltovisibility 类我可以在我的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RefreshAllButton 时，会触发一个调用的方法RefreshAll_Click()，我想检查一个if条件哪些通道可用。如果是，则执行一些语句。我在 C++ 中完成了如下操作：

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
    }

我怎样才能做到这一点？:)

4

2 回答 2

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，因为ObservableCollection<T>implements IList<T>，您可以索引到集合中，就像在您的 C++ 代码中一样：

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

如果您只需要一个布尔值，如果至少有一个通道可用，那么 linq 是最好的：

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

从我之前（现已删除）的评论中移出，这里有一些不请自来的进一步建议：

您应该删除 line channelList = new ObservableCollection<VoltageBoardChannel>();，因为您会通过在下一行 ( channelList = bavaria1Channels;) 中重新分配引用来立即丢弃该对象。实际上，您根本不需要bavaria1Channels（也不需要构造函数）；您可以channelList使用集合初始化表达式声明和初始化，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},     
};
于 2012-10-17T05:23:37.837 回答
1 
if (bavaria1Channels.Any(c => c.IsAvailable)) //Any channel available
{
    //Execute some code :)
}
于 2012-10-17T05:27:18.930 回答