我正在使用在简单 WPF 应用程序的 MainWindow 类中定义的 ObservableCollection
。由于某种原因,列表会更新(我可以在调试时看到这一点),但 UI 不会更新。
现在,如果我创建一个 Timer
并循环它,我可以通过设置 ItemSource
来更新 DataGrid
。这可行,但会导致我的 DataGrid 中出现可怕的闪烁。
public ObservableCollection<CalculatedData> calculatedData { get; set; }
进一步深入我的代码,我使用这一行来实际更新数据或将数据添加到列表中。
calculatedData = await CalculateData();
CalculateData
函数定义如下:
private Task<ObservableCollection<CalculatedData>> CalculateData()
{
return Task.Run(() =>
{
ObservableCollection<CalculatedData> cdList = new ObservableCollection<CalculatedData>();
// Do a lot of stuff
return cdList;
});
}
对于我的 xaml
,我有一个简单的 DataGrid,如下所示:
<DataGrid Name="dataGrid" ItemsSource="{Binding calculatedData}" IsReadOnly="True" CanUserReorderColumns="False" CanUserResizeColumns="False" CanUserSortColumns="False" CanUserResizeRows="False" AutoGeneratingColumn="dataGrid_AutoGeneratingColumn" />
问题:为什么 DataGrid 没有更新?由于我没有重新绑定(bind),这会解决我的闪烁问题吗?
-
更新
我什至将我的主要声明更改为以下内容(因为我看到它是这样做的),但我仍然没有让它工作。
private ObservableCollection<CalculatedData> calculatedData = new ObservableCollection<CalculatedData>();
public ObservableCollection<CalculatedData> CalculatedData
{
get { return calculatedData; }
set
{
calculatedData = value;
}
}
XAML:
<DataGrid Name="dataGrid" ItemsSource="{Binding CalculatedData}" IsReadOnly="True" CanUserReorderColumns="False" CanUserResizeColumns="False" CanUserSortColumns="False" CanUserResizeRows="False" AutoGeneratingColumn="dataGrid_AutoGeneratingColumn" />
最佳答案
如果你只是这样做:
private async void Window_Loaded(object sender, RoutedEventArgs e)
{
calculatedData = await CalculateData();
dataGrid1.ItemsSource = calculatedData;
}
它会起作用的。我猜您的 XAML 绑定(bind)可能无法正常工作,因为 DataContext
未定义。
编辑:这是完整的代码,
主窗口:
public partial class MainWindow : Window
{
public ObservableCollection<CalculatedData> calculatedData { get; set; }
public MainWindow()
{
InitializeComponent();
}
private async void Window_Loaded(object sender, RoutedEventArgs e)
{
calculatedData = await CalculateData();
dataGrid1.ItemsSource = calculatedData;
}
private Task<ObservableCollection<CalculatedData>> CalculateData()
{
return Task.Run(() =>
{
ObservableCollection<CalculatedData> cdList = new ObservableCollection<CalculatedData>();
// Do a lot of stuff
cdList.Add(new CalculatedData { Data1 = 1, Data2 = 2, Data3 = 3 });
cdList.Add(new CalculatedData { Data1 = 1, Data2 = 2, Data3 = 3 });
cdList.Add(new CalculatedData { Data1 = 1, Data2 = 2, Data3 = 3 });
cdList.Add(new CalculatedData { Data1 = 1, Data2 = 2, Data3 = 3 });
cdList.Add(new CalculatedData { Data1 = 1, Data2 = 2, Data3 = 3 });
return cdList;
});
}
}
XAML:
<Grid>
<DataGrid x:Name="dataGrid1" Margin="0" />
</Grid>
结果:
编辑 2:添加一个按钮并将代码稍微移动一下,以便您可以测试。
public partial class MainWindow : Window
{
public ObservableCollection<CalculatedData> calculatedData { get; set; }
int i;
public MainWindow()
{
InitializeComponent();
//initialize your binding collection
calculatedData = new ObservableCollection<CalculatedData>();
}
private async void Window_Loaded(object sender, RoutedEventArgs e)
{
i = 1;
//create initial data and bind to data grid
calculatedData = await CalculateData();
dataGrid1.ItemsSource = calculatedData;
}
private Task<ObservableCollection<CalculatedData>> CalculateData()
{
return Task.Run(() =>
{
ObservableCollection<CalculatedData> cdList = new ObservableCollection<CalculatedData>();
// Do a lot of stuff
for (int j = 0; j < 5; j++)
{
cdList.Add(new CalculatedData { Data1 = i, Data2 = i + 1, Data3 = i + 2 });
i++;
}
return cdList;
});
}
private async void button1_Click(object sender, RoutedEventArgs e)
{
//place new data in a temporary collection
ObservableCollection<CalculatedData> newData = await CalculateData();
//add new data to the collection bound to the data grid
//preferably, don't just replace it
//any business logic you may need for adding,
//deleting, filtering data, etc goes here
foreach (CalculatedData cd in newData)
calculatedData.Add(cd);
}
}
关于c# - DataGrid 的数据绑定(bind)不起作用?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/31768551/