我正在面对这个奇怪的问题。它看起来像是众所周知的问题。我试图找到解决方案。花了一整天。但仍然没有用。我尝试的所有解决方案都没有帮助我。
<ListBox ItemsSource="{Binding ElementName=root,Path=ItemsSource,UpdateSourceTrigger=PropertyChanged}" DisplayMemberPath="Category" Background="Coral"></ListBox>
root是用户控制的名称,而项目源是依赖项属性。
public static readonly DependencyProperty ItemsSourceProperty =
DependencyProperty.Register("ItemsSource", typeof(IEnumerable), typeof(LineBarChart));
public IEnumerable ItemsSource
{
get { return (IEnumerable)GetValue(ItemsSourceProperty); }
set {
SetValue(ItemsSourceProperty, value); }
}
现在,在mainwindow.xaml中,我创建了一个用户控件的实例,并以这种方式与UserControl的项目源相结合。
ItemsSource="{Binding ElementName=Window,Path=LineBarData,UpdateSourceTrigger=PropertyChanged}"
windows是主窗口的名称
主窗口后面的代码是:
public partial class MainWindow : Window
{
private ObservableCollection<LineBarChartData> lineBarData;
internal ObservableCollection<LineBarChartData> LineBarData
{
get
{
return lineBarData;
}
set
{
lineBarData = value;
}
}
public MainWindow()
{
InitializeComponent();
LineBarData = new ObservableCollection<LineBarChartData>();
LineBarData.Add(new LineBarChartData() { Category = "January", ValueX = 10, ValueY = 50 });
LineBarData.Add(new LineBarChartData() { Category = "February", ValueX = 20, ValueY = 60 });
LineBarData.Add(new LineBarChartData() { Category = "March", ValueX = 30, ValueY = 70 });
LineBarData.Add(new LineBarChartData() { Category = "April", ValueX = 40, ValueY = 80 });
}
和LineBarchartData类如下
public class LineBarChartData : INotifyPropertyChanged
{
private string _category;
public string Category
{
get { return this._category; }
set { this._category = value; this.OnPropertyChanged("Category"); }
}
private double _valueX;
public double ValueX
{
get { return this._valueX; }
set { this._valueX = value; this.OnPropertyChanged("ValueX"); }
}
private double _valueY;
public double ValueY
{
get { return this._valueY; }
set { this._valueY= value; this.OnPropertyChanged("ValueY"); }
}
//private Brush _color;
//public Brush Color
//{
// get { return this._color; }
// set { this._color = value; this.OnPropertyChanged("Color"); }
//}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
在列表框中没有显示任何内容。我找不到我的错误。请帮助!
谢谢。
wpf数据绑定仅适用于公共属性,因此
internal ObservableCollection<LineBarChartData> LineBarData { get; set; }
应该是
public ObservableCollection<LineBarChartData> LineBarData { get; set; }
您也可能会删除衬板并写下属性(仅读(:
public ObservableCollection<LineBarChartData> LineBarData { get; }
= new ObservableCollection<LineBarChartData>();
然后添加这样的值:
public MainWindow()
{
InitializeComponent();
LineBarData.Add(new LineBarChartData() { ... });
...
}
注意,在绑定上设置 UpdateSourceTrigger=PropertyChanged
仅在是twoway或OnewayTosource绑定时具有效果,并且绑定实际上更新了源属性。在您的绑定中并非如此。