【发布时间】：2019-02-28 04:05:49
【问题描述】：
MVVM 新手正在寻找有关数据网格绑定的一些指导。我很难设置我可以看到数据网格单元格的内容已更改的属性。我一开始很简单，我试图用货币代码设置一个可更新的国家列表。有没有办法可以将我的网格列单元格绑定到视图模型中的属性？到目前为止，我刚刚介绍了 CurrencyCode 的属性，但我从未执行过 setter。我究竟做错了什么？
型号：
using System.Linq;
使用 System.Collections.ObjectModel；
命名空间 AdminTool.DataModel.Repositories { 公共类 AccountingRepository : BaseRepository { 私有 AdminToolEntities 实体 = new AdminToolEntities();
// Country List
public ObservableCollection<CountryData> GetCountryList()
{
var result = (from c in entities.Countries
from u in entities.Currencies.Where(u => u.ID == c.CurrencyID).DefaultIfEmpty()
select new CountryData { IsChanged = false,
ID = c.ID,
CountryName = c.CountryName,
CountryCodeISO = c.CountryCodeISO,
CurrencyCode = u.CurrencyCode})
.OrderBy(o => o.CountryName)
.ToList();
return new ObservableCollection<CountryData>(result);
}
public void SaveCountryList(ObservableCollection<CountryData> countryList)
{
var result = (from l in countryList
from c in entities.Countries.Where(c => c.ID == l.ID)
from u in entities.Currencies.Where(u => u.CurrencyCode == l.CurrencyCode).DefaultIfEmpty()
where l.IsChanged
select l)
.ToList();
foreach (CountryData cd in result)
{
Country c = (Country)entities.Countries.Where(l => l.ID == cd.ID).FirstOrDefault();
if (c == null) // new entry
{
c = new Country();
entities.Countries.Add(c);
}
c.CountryName = cd.CountryName;
c.CountryCodeISO = cd.CountryCodeISO;
c.Currency = entities.Currencies.Where(u => u.CurrencyCode == cd.CurrencyCode).FirstOrDefault();
}
entities.SaveChanges();
}
}
/// <summary>
/// Data structures
/// </summary>
public class CountryData
{
public int ID { get; set; }
public string CountryName { get; set; }
public string CountryCodeISO { get; set; }
public string CurrencyCode { get; set; }
public bool IsChanged { get; set; }
}
}
查看：
<Window x:Class="AdminTool.Desktop.View.CountryList"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:diag="clr-namespace:System.Diagnostics;assembly=WindowsBase"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:vm="clr-namespace:AdminTool.Desktop.ViewModel"
Title="AdminTool" Height="600" Width="500">
<Window.DataContext>
<vm:AccountingViewModel/>
</Window.DataContext>
<Grid>
<DataGrid Name="dgCountryList"
ItemsSource="{Binding CountryList, Mode=TwoWay}"
SelectedItem="{Binding Path=SelectedCountry, Mode=TwoWay}"
HorizontalAlignment="Left" VerticalAlignment="Top" Height="450" Width="450" Margin="20,20,0,0"
AutoGenerateColumns="False"
SelectionMode="Single"
SelectionUnit="FullRow"
GridLinesVisibility="All"
CanUserDeleteRows="True"
CanUserAddRows="True">
<DataGrid.RowStyle>
<Style TargetType="{x:Type DataGridRow}">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsChanged}" Value="true" >
<Setter Property="Background" Value="LightGreen" />
</DataTrigger>
</Style.Triggers>
</Style>
</DataGrid.RowStyle>
<DataGrid.Columns>
<!--<DataGridTextColumn Header="ID" Binding="{Binding ID}" Width="50" />-->
<DataGridTextColumn Header="Country" Binding="{Binding Path=CountryName, Mode=TwoWay}" Width="250" />
<DataGridTextColumn Header="ISO Code" Binding="{Binding Path=CountryCodeISO, Mode=TwoWay}" Width="80" />
<DataGridTextColumn Header="Currency" Binding="{Binding Path=CurrencyCode, Mode=TwoWay}" Width="80" />
</DataGrid.Columns>
</DataGrid>
<Button Content="Save" Command="{Binding Path=SaveCommand}" IsEnabled="{Binding Path=UpdateButtonEnabled}" HorizontalAlignment="Left" Margin="223,512,0,0" VerticalAlignment="Top" Width="75"/>
<Button Content="Cancel" Command="{Binding Path=CancelCommand}" HorizontalAlignment="Left" Margin="343,512,0,0" VerticalAlignment="Top" Width="75"/>
</Grid>
视图模型：
using System.Collections.ObjectModel;
使用 AdminTool.DataModel.Repositories； 使用 AdminTool.Helpers;
命名空间 AdminTool.Desktop.ViewModel {
public class AccountingViewModel : ViewModelBase
{
private ObservableCollection<CountryData> _countryList;
public ObservableCollection<CountryData> CountryList
{
get { return _countryList; }
set
{
_countryList = value;
RaisePropertyChanged("CountryList");
}
}
private CountryData _selectedCountry;
public CountryData SelectedCountry
{
get { return _selectedCountry; }
set
{
_selectedCountry = value;
RaisePropertyChanged("SelectedCountry");
}
}
private string currencyCode;
public string CurrencyCode
{
get { return currencyCode; }
set {
currencyCode = value;
SelectedCountry.IsChanged = true;
}
}
private bool updateButtonEnabled = false;
public bool UpdateButtonEnabled
{
get { return updateButtonEnabled; }
set { updateButtonEnabled = value;
RaisePropertyChanged("UpdateButtonEnabled");
}
}
#region Commands -----------------------------------------------------------------------------------
public RelayCommand SaveCommand { get; set; }
public RelayCommand CancelCommand { get; set; }
#endregion
/// <summary>
/// Initializes a new instance of the MainViewModel class.
/// </summary>
public AccountingViewModel()
{
SaveCommand = new RelayCommand(Save);
CancelCommand = new RelayCommand(Cancel);
AccountingRepository repo = new AccountingRepository();
CountryList = repo.GetCountryList();
}
#region Public methods -----------------------------------------------------------------------------
void Save(object parameter)
{
AccountingRepository repo = new AccountingRepository();
repo.SaveCountryList(CountryList);
}
void Cancel(object parameter)
{
}
#endregion
}
}
提前感谢您的帮助。
【问题讨论】：
-
我不知道你是否处理了事件属性更改？
标签： c# wpf mvvm binding datagrid