问题
I am a C++ developer and I recently moved to C#. I am working on a wpf app using MVVM pattern. I have a groupboxbox in my xaml file which I have divided into two columns. One column contains the dynamically generated set of radiobuttons and other colums contains a label and many comboboxes.
XAML:
<GroupBox Header="Daughter Cards" Height="Auto" HorizontalAlignment="Stretch" Margin="20,5,20,20" Name="groupBox2" VerticalAlignment="Stretch" Width="Auto">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition Width="220" />
</Grid.ColumnDefinitions>
<Grid Grid.Column="0">
<ItemsControl ItemsSource="{Binding SlotChildren}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<UniformGrid />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<RadioButton Content="{Binding SlotButtons}" Margin="0,10,0,0" IsChecked="{Binding IsChecked}" GroupName="SlotGroup" Height="15" Width="80" HorizontalAlignment="Center" VerticalAlignment="Center"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
<Grid Grid.Column="1">
<ComboBox ItemsSource="{Binding DaughterBoardBoxList}" SelectedItem="{Binding SelectedDaughterBoardBoxList, Mode=TwoWay}" SelectedIndex="0" Height="23" HorizontalAlignment="Center" Margin="0" Name="comboBox5" VerticalAlignment="Center" Width="158" />
<ComboBox ItemsSource="{Binding DaughterVersionBoxList}" SelectedItem="{Binding SelectedDaughterVersionBoxList, Mode=TwoWay}" SelectedIndex="0" Height="23" HorizontalAlignment="Center" Margin="0" Name="comboBox6" VerticalAlignment="Center" Width="158" />
<ComboBox ItemsSource="{Binding DaughterSerialBoxList}" SelectedItem="{Binding SelectedDaughterSerialBoxList, Mode=TwoWay}" SelectedIndex="0" Height="23" HorizontalAlignment="Center" Margin="0" Name="comboBox7" VerticalAlignment="Center" Width="158" />
<Label Content="{Binding DaughterStatus}" Height="25" HorizontalAlignment="Center" Margin="0" Name="DaughterCardLabel" VerticalAlignment="Center" Width="170" />
<ComboBox Height="23" ItemsSource="{Binding I2CAddressList}" SelectedItem="{Binding SelectedI2CAddressList, Mode=TwoWay}" SelectedIndex="0" Grid.Row="0" HorizontalAlignment="Center" Margin="0,0,0,0" Name="comboBox1" VerticalAlignment="Center" Width="200" />
<ComboBox Height="23" ItemsSource="{Binding BoardBoxList}" SelectedItem="{Binding SelectedBoardBoxList, Mode=TwoWay}" SelectedIndex="0" Grid.Row="1" HorizontalAlignment="Center" Margin="0,0,0,0" Name="comboBox2" VerticalAlignment="Center" Width="200" />
<ComboBox Height="23" ItemsSource="{Binding VersionBoxList}" SelectedItem="{Binding SelectedVersionBoxList, Mode=TwoWay}" SelectedIndex="0" Grid.Row="2" HorizontalAlignment="Center" Margin="0,0,0,0" Name="comboBox3" VerticalAlignment="Center" Width="200" />
<ComboBox Height="23" ItemsSource="{Binding SerialBoxList}" SelectedItem="{Binding SelectedSerialBoxList, Mode=TwoWay}" SelectedIndex="0" Grid.Row="3" HorizontalAlignment="Center" Margin="0,0,0,0" Name="comboBox4" VerticalAlignment="Center" Width="200" />
</Grid>
</Grid>
</GroupBox>
EEPROMViewModel Class: DataContext of xaml is set to this class. In the same class:
Byte[] sendBuf = new Byte[256];
Byte[] readBuf = new Byte[256];
public ObservableCollection<EEPROMSlotViewModel> SlotChildren { get; set; }
public ObservableCollection<string> _I2CAddressList;
public ObservableCollection<string> _BoardBoxList;
public ObservableCollection<string> _VersionBoxList;
public ObservableCollection<string> _SerialBoxList;
public ObservableCollection<string> _DBoardBoxList;
public ObservableCollection<string> _DVersionBoxList;
public ObservableCollection<string> _DSerialBoxList;
public EEPROMViewModel()
{
SlotChildren = new ObservableCollection<EEPROMSlotViewModel>();
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "0 : None", ID = 0 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "1 : None", ID = 1 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "2 : None", ID = 2 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "3 : None", ID = 3 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "4 : None", ID = 4 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "5 : None", ID = 5 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "6 : None", ID = 6 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "7 : None", ID = 7 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "8 : None", ID = 8 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "9 : None", ID = 9 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "10 : None", ID = 10 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "11 : None", ID = 11 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "12 : None", ID = 12 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "13 : None", ID = 13 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "14 : None", ID = 14 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "15 : None", ID = 15 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "16 : None", ID = 16 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "17 : None", ID = 17 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "18 : None", ID = 18 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "19 : None", ID = 19 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "20 : None", ID = 20 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "21 : None", ID = 21 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "22 : None", ID = 22 });
SlotChildren.Add(new EEPROMSlotViewModel() { SlotButtons = "23 : None", ID = 23 });
var myboard = new[]
{
"",
"S1010012", // redhook
"S1010018", // bavaria
"S1010020" // flying dog
};
var myVariant = new[]
{
"",
"001A",
"001B",
"001C",
"002A",
"002B",
"002C",
"003A",
"003B",
"003C",
};
_I2CAddressList = new ObservableCollection<string>();
_BoardBoxList = new ObservableCollection<string>(myboard);
_VersionBoxList = new ObservableCollection<string>(myVariant);
_SerialBoxList = new ObservableCollection<string>();
for (int i = 1; i < 200; i++)
{
_SerialBoxList.Add(i.ToString());
}
//List of I2C Address
_I2CAddressList.Add("0x50");
_I2CAddressList.Add("0x53");
this.SelectedI2CAddressList = this._I2CAddressList[1];
this.SelectedBoardBoxList = this.BoardBoxList[2];
this.SelectedVersionBoxList = this.VersionBoxList[2];
this.SelectedSerialBoxList = this.SerialBoxList[0];
var myDBoards = new[]
{
"",
"S1010013",
"S1010014",
"S1010015",
"S1010017",
"S1010019",
"S1010021",
"S1010023",
"S1010026",
"S1110029",
};
_DBoardBoxList = new ObservableCollection<string>(myDBoards);
_DVersionBoxList = new ObservableCollection<string>(myVariant);
_DSerialBoxList = new ObservableCollection<string>();
for (int j = 1; j < 500; j++)
{
_DSerialBoxList.Add(j.ToString());
}
}
public ObservableCollection<string> I2CAddressList
{
get { return _I2CAddressList; }
set
{
_I2CAddressList = value;
OnPropertyChanged("I2CAddressList");
}
}
private string _SelectedI2CAddressList;
public string SelectedI2CAddressList
{
get { return _SelectedI2CAddressList; }
set
{
_SelectedI2CAddressList = value;
OnPropertyChanged("SelectedI2CAddressList");
}
}
public ObservableCollection<string> BoardBoxList
{
get { return _BoardBoxList; }
set
{
_BoardBoxList = value;
OnPropertyChanged("BoardBoxList");
}
}
private string _SelectedBoardBoxList;
public string SelectedBoardBoxList
{
get { return _SelectedBoardBoxList; }
set
{
_SelectedBoardBoxList = value;
OnPropertyChanged("SelectedBoardBoxList");
}
}
public ObservableCollection<string> VersionBoxList
{
get { return _VersionBoxList; }
set
{
_VersionBoxList = value;
OnPropertyChanged("VersionBoxList");
}
}
private string _SelectedVersionBoxList;
public string SelectedVersionBoxList
{
get { return _SelectedVersionBoxList; }
set
{
_SelectedVersionBoxList = value;
OnPropertyChanged("SelectedVersionBoxList");
}
}
public ObservableCollection<string> SerialBoxList
{
get { return _SerialBoxList; }
set
{
_SerialBoxList = value;
OnPropertyChanged("SerialBoxList");
}
}
private string _SelectedSerialBoxList;
public string SelectedSerialBoxList
{
get { return _SelectedSerialBoxList; }
set
{
_SelectedSerialBoxList = value;
OnPropertyChanged("SelectedSerialBoxList");
}
}
char[] version =
{
'A', 'U', 'D', 'I', 'E', 'N', 'C', 'E', // name
'0', '0', '0', '0', '0', '0', '0', '0' , // reserved, firmware size
'0', '0', '0', '0', '0', '0', '0', '0' , // board number
'0', '0', '0', '0', '0', '0', '0', '0' , // variant, version, serial
'0', '0', '0', '0', '0', '0', '0', '0' // date code, reserved
};
public ObservableCollection<string> DaughterBoardBoxList
{
get { return _DBoardBoxList; }
set
{
_DBoardBoxList = value;
OnPropertyChanged("DaughterBoardBoxList");
}
}
public string _SelectedDBoardBoxList;
public string SelectedDaughterBoardBoxList
{
get { return _SelectedDBoardBoxList; }
set
{
_SelectedDBoardBoxList = value;
OnPropertyChanged("SelectedDaughterBoardBoxList");
}
}
public ObservableCollection<string> DaughterVersionBoxList
{
get { return _DVersionBoxList; }
set
{
_DVersionBoxList = value;
OnPropertyChanged("DaughterVersionBoxList");
}
}
public string _SelectedDVersionBoxList;
public string SelectedDaughterVersionBoxList
{
get { return _SelectedDVersionBoxList; }
set
{
_SelectedDVersionBoxList = value;
OnPropertyChanged("SelectedDaughterVersionBoxList");
}
}
public ObservableCollection<string> DaughterSerialBoxList
{
get { return _DSerialBoxList; }
set
{
_DSerialBoxList = value;
OnPropertyChanged("DaughterSerialBoxList");
}
}
private string _SelectedDSerialBoxList;
public string SelectedDaughterSerialBoxList
{
get { return _SelectedDSerialBoxList; }
set
{
_SelectedDSerialBoxList = value;
OnPropertyChanged("SelectedDaughterSerialBoxList");
}
}
private string _DaughterStatus = "Not Retrieved yet";
public string DaughterStatus
{
get { return _DaughterStatus; }
set
{
_DaughterStatus = value;
OnPropertyChanged("DaughterStatus");
}
}
EEPROMSlotViewModel Class:
EEPROMViewModel mVMModel = new EEPROMViewModel();
private string _SlotButtons;
public string SlotButtons
{
get; set;
}
private int _ID;
public int ID
{
get; set;
}
private bool _isChecked;
public bool IsChecked
{
get { return _isChecked; }
set
{
_isChecked = value;
OnSlotClick(ID);
OnPropertyChanged("IsChecked");
}
}
public void OnSlotClick(int Index)
{
string label = string.Empty;
if (Index >= 0 && Index < 24)
{
//getShortName(Index, label);
if (label == string.Empty)
{
SlotButtons = Convert.ToString(Index + " : None");
}
else
{
SlotButtons = Convert.ToString(Index + " :" + label);
}
}
if (label != string.Empty)
{
label += " - ";
//getLongName(Index, label);
}
else
{
label = "No device found at this slot";
}
mVMModel.DaughterStatus = label; // displays it in the label
}
When I am trying to run the application, it crashes and throws an exception as stackoverflow. The problem seems to be present in EEPROMSlotViewModel when I ccheck any radiobutton and the articular method gets called.
Whats the mistake I am doing here? :( Please help :)
回答1:
Your problem is on mVMModel.DaughterStatus = label; // displays it in the label you are probably instantiating EEPROMViewModel class inside EEPROMSlotViewModel which causes infinite loop.
To solve this you need to access your parentVM it can be done using Interfaces to show only the DaughterStatus but quick answer could be as below :
Add a property to your EEPROMSlotViewModel :
public EEPROMViewModel ParentVM
{
get { return _parentVm; }
set
{
_parentVm = value;
OnPropertyChanged("ParentVM");
}
}
Instead of mVMModel.DaughterStatus = label; put ParentVM.DaughterStatus = label;
And finally :
SlotChildren.Add(new EEPROMSlotViewModel() { ParentVM = this, SlotButtons = "0 : None", ID = 0 });
来源：https://stackoverflow.com/questions/13133800/program-crashes-when-dynamically-generated-radiobuttons-are-created-in-wpf