数据网格 WPF 字段

Question

我有一个包含 3 个 DataGridTextColumns 的数据网格

<DataGrid.Columns>
    <DataGridTextColumn   Header="Field Name" Binding="{Binding Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"  />
    <DataGridTextColumn  x:Name="BeginFields"  Header="Begin" Binding="{Binding Begin, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
    <DataGridTextColumn  x:Name="LengthFields"  Header="Length" Binding="{Binding Length, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
</DataGrid.Columns>

所有三个 DataGridTextColumns 数据都添加到一个 ObservableCollection 中。我遍历集合以获取一个实例，并为下一行设置值。

如果任何字段得到更新，程序需要相应地更新。

现在我只能操作开始字段，不能操作长度字段。

将起始字段视为文本文档中的一行，将长度字段视为文本文档中的下一行，这两个字段必须完全分开并且永远不会相互重叠，我希望我在我想要完成的事情我对编程还很陌生，而且我的算法技能并不强大。请帮助我，如果我说的话没有意义，请告诉我，我会尽我所能详细说明。有关详细信息，请参阅代码。

谢谢！！

The DataGrid View

我现在将过去的代码

public MainWindow()
{

    InitializeComponent();
    dataGrid.ItemsSource = MWVM.FieldsCollection;

    fileButton.Click += FileButton_Click;
    loadPresetButton.Click += LoadPresetButton_Click;
    savePresetButton.Click += SavePresetButton_Click;
    clipboardButton.Click += ClipboardButton_Click;
    saveButton.Click += SaveButton_Click;

    ****dataGrid.SelectedCellsChanged += ((o, e) =>
    {
        int track = 0;

        foreach (Field f in MWVM.FieldsCollection)
        {
            track += f.Length;


            f.Begin = track - f.Length;
        }
    }); ****
}

public class Field : ViewModelsBase
{

    private string _name;
    public string Name
    {
        get
        {
            return _name;
        }
        set
        {
            _name = value;
            RaisePropertyChanged("Name");

        }

    }
    private int _begin;

    public int Begin
    {
        get
        {
            return _begin;
        }
        set
        {
            if (value != _begin)
            {
                _begin = value;
                RaisePropertyChanged("Begin");
            }

        }
    }


    private int _length;
    public int Length
    {
        get { return _length; }

        set
        {
            if (value != _length)
            {
                _length = value;
                RaisePropertyChanged("Length");
            }
        }
    }

    [JsonIgnore]
    public string Blank { get; set; } = "";
}

public class MainWindowViewModel : ViewModelsBase
{
    public ObservableCollection<Field> fieldsCollection;

    public MainWindowViewModel()
    {
        _fields = CreateFieldsCollection();
    }



    private ObservableCollection<Field> CreateFieldsCollection()
    {
        fieldsCollection = new ObservableCollection<Field>();
        return fieldsCollection;  
    }

    ObservableCollection<Field> _fields;

    public ObservableCollection<Field> FieldsCollection
    {
        get

        {
            return _fields;
        }
        set
        {
            if (_fields != value)
            {
                _fields = value;
                RaisePropertyChanged("FieldsCollection"); 
            }

        }
    }
}

Answer 1

您应该在视图模型中处理此逻辑class。

您可以处理添加到 ObservableCollection<Field> 的每个 Field 对象的 PropertyChanged 事件，并相应地重新计算 Begin 和 Length 字段。请参考以下示例代码，您应该可以从中得到启发：

public class MainWindowViewModel : ViewModelsBase
{
    public MainWindowViewModel()
    {
        _fields = CreateFieldsCollection();
        _fields.CollectionChanged += _fields_CollectionChanged;
    }

    private ObservableCollection<Field> CreateFieldsCollection()
    {
        ObservableCollection<Field> fieldsCollection = new ObservableCollection<Field>();
        fieldsCollection.Add(new Field() { Begin = 0, Length = 5 });
        fieldsCollection.Add(new Field() { Begin = 5, Length = 5 });
        fieldsCollection.Add(new Field() { Begin = 10, Length = 5 });
        fieldsCollection.Add(new Field() { Begin = 15, Length = 5 });
        fieldsCollection.Add(new Field() { Begin = 20, Length = 5 });
        foreach (Field field in fieldsCollection)
            field.PropertyChanged += item_PropertyChanged;
        return fieldsCollection;
    }

    private void _fields_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
    {
        if (e.NewItems != null)
        {
            foreach (object field in e.NewItems)
            {
                (field as INotifyPropertyChanged).PropertyChanged
                    += new PropertyChangedEventHandler(item_PropertyChanged);
            }
        }

        if (e.OldItems != null)
        {
            foreach (object country in e.OldItems)
            {
                (country as INotifyPropertyChanged).PropertyChanged
                    -= new PropertyChangedEventHandler(item_PropertyChanged);
            }
        }

    }

    private void item_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        if (_fields.Count < 2)
            return;

        switch(e.PropertyName)
        {
            case "Length":
                //recalculate the begin of each field
                RecalculateBegin();
                break;
            case "Begin":
                Field modifiedField = sender as Field;
                int indexOfModifiedField = FieldsCollection.IndexOf(modifiedField);
                if(indexOfModifiedField > 0)
                {
                    //recalculate the length of the previous field:
                    Field previousField = FieldsCollection[indexOfModifiedField - 1];
                    previousField.Length = modifiedField.Begin - previousField.Begin;
                }
                //...and the recalculate the begin of the rest of the fields:
                RecalculateBegin();
                break;
        }
    }

    private void RecalculateBegin()
    {
        int length = _fields[0].Begin + _fields[0].Length;
        for (int i = 1; i < FieldsCollection.Count; ++i)
        {
            FieldsCollection[i].Begin = length;
            length += FieldsCollection[i].Length;
        }
    }

    private ObservableCollection<Field> _fields;
    public ObservableCollection<Field> FieldsCollection
    {
        get { return _fields; }
        set
        {
            if (_fields != value)
            {
                _fields = value;
                RaisePropertyChanged("FieldsCollection");
            }
        }
    }
}

数据网格 WPF 字段

DataGrid WPF Fields

c#

wpf

datagrid

field

cell