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Im在我的windows phone項目中遇到了一些麻煩。Observable collection not updated
我用編程方式創建並添加到我的視圖中的項目似乎在使用可觀察集合時得到更新。 viewmodel和datacontext是正確的，但在視圖中沒有任何反應。
查看：
async void OnLoaded(object sender, RoutedEventArgs e)
{
if (InspectionMainMenu.Children.Count() > 0)
return;
await InspectionMainPageViewModel.Instance.LoadData();
this.DataContext = InspectionMainPageViewModel.Instance;
int nrOfGridRows = InspectionMainPageViewModel.Instance.MenuItems.Count/2;
//check if there is need to add another row
if (InspectionMainPageViewModel.Instance.MenuItems.Count % 2 > 0)
nrOfGridRows++;
Grid grid1 = new Grid();
grid1.Name = "grid1";
grid1.Margin = new Thickness { Top = 0, Left = 0, Bottom = 12, Right = 0 };
InspectionMainMenu.Children.Add(grid1); // Note: parentControl is whatever control you are added this to
grid1.ColumnDefinitions.Add(new ColumnDefinition());
grid1.ColumnDefinitions.Add(new ColumnDefinition());
//grid1.DataContext = InspectionMainPageViewModel.Instance.MenuItems;
//Binding myBinding = new Binding("MenuItems");
//myBinding.Source = InspectionMainPageViewModel.Instance;
//grid1.SetBinding(Grid.DataContextProperty, myBinding);
//Add the dynamic rows
for (int i = 0; i < nrOfGridRows; i++)
{
grid1.RowDefinitions.Add(new RowDefinition());
}
int currentRow = 0;
int currentColumn = 0;
int currentItem = 0;
foreach(InspectionMenuItem item in InspectionMainPageViewModel.Instance.MenuItems)
{
InspectionCategory menuBox = new InspectionCategory();
menuBox.Title = item.Header;
menuBox.BgColor = App.Current.Resources["Blue"].ToString();
menuBox.SetValue(Grid.RowProperty, currentRow);
menuBox.SetValue(Grid.ColumnProperty, currentColumn);
menuBox.Margin = new Thickness { Top = 0, Left = 6, Bottom = 6, Right = 6 };
menuBox.IconType = "/images/appicons/"+ item.IconName +"";
menuBox.Tap += test2_Tap;
grid1.Children.Add(menuBox);
if (currentItem % 2 > 0)
currentRow++;
if (currentItem % 2 > 0)
currentColumn = 0;
else
currentColumn = 1;
currentItem++;
}
}
型號：
public class InspectionMenuItem : ViewModelBase
{
string _header;
string _bgColor;
string _iconName;
bool _isRead;
public int id { get; set; }
/// <summary>
/// Header.
/// </summary>
public string Header
{
get
{
return _header;
}
set
{
_header = value;
OnPropertyChanged("Header");
}
}
/// <summary>
/// BgColor.
/// </summary>
public string BgColor
{
get
{
return _bgColor;
}
set
{
_bgColor = value;
OnPropertyChanged("BgColor");
}
}
/// <summary>
/// IconName
/// </summary>
public string IconName
{
get
{
return _iconName;
}
set
{
_iconName = value;
OnPropertyChanged("IconName");
}
}
}
視圖模型：
public class InspectionMainPageViewModel : ViewModelBase, INotifyPropertyChanged
{
private static InspectionMainPageViewModel instance;
private TaskCompletionSource<bool> tcs = new TaskCompletionSource<bool>();
private ObservableCollection<InspectionMenuItem> menuItems;
private ObservableCollection<ProtocolItem> protocolItems;
private string chassisNumber;
/// <summary>
/// Initializes a new instance of the <see cref="MainViewModel"/> class.
/// </summary>
public InspectionMainPageViewModel()
{
this.menuItems = new ObservableCollection<InspectionMenuItem>();
this.protocolItems = new ObservableCollection<ProtocolItem>();
}
/// <summary>
/// Gets the instance.
/// </summary>
public static InspectionMainPageViewModel Instance
{
get
{
if (instance == null)
{
instance = new InspectionMainPageViewModel();
}
return instance;
}
}
public ObservableCollection<InspectionMenuItem> MenuItems
{
get
{
return this.menuItems;
}
}
public ObservableCollection<ProtocolItem> ProtocolItems
{
get
{
return this.protocolItems;
}
}
public string ChassisNumber
{
get
{
return this.chassisNumber;
}
}
/// <summary>
/// Gets or sets a value indicating whether this instance is data loaded.
/// </summary>
public bool IsDataLoaded
{
get;
set;
}
public async Task LoadData()
{
if (this.IsDataLoaded)
{
return;
}
GetMenuItems();
GetProtocolItems();
SetDummyData();
// this.news = await CRMService.GetNews();
this.IsDataLoaded = true;
}
private void SetDummyData()
{
this.chassisNumber = "JN1HS36P8LW107899";
}
public void GetMenuItems()
{
this.menuItems.Add(new InspectionMenuItem { Header = "Kund", IconName = "user_128.png", BgColor = "Blue" });
this.menuItems.Add(new InspectionMenuItem { Header = "Fordon", IconName = "car_128.png", BgColor = "Blue" });
this.menuItems.Add(new InspectionMenuItem { Header = "Identifiering", IconName = "check_128.png", BgColor = "Blue" });
this.menuItems.Add(new InspectionMenuItem { Header = "Anmärkning", IconName = "user_128.png", BgColor = "Blue" });
this.menuItems.Add(new InspectionMenuItem { Header = "Test", IconName = "user_128.png", BgColor = "Blue" });
}
public void GetProtocolItems()
{
this.protocolItems.Add(new ProtocolItem { Header = "Spindelled", Summary = "Fastsättning bristfällig", ProtocolImageUri = "user_128.png" , State="Tidigare anmärkningar"});
this.protocolItems.Add(new ProtocolItem { Header = "Färdbroms bromsskiva", Summary = "Risk för bromsbortfall", ProtocolImageUri = "user_128.png", State = "Tidigare anmärkningar" });
this.protocolItems.Add(new ProtocolItem { Header = "Infästning bromssystem", Summary = "Sprickor", ProtocolImageUri = "user_128.png", State = "Tidigare anmärkningar" });
this.protocolItems.Add(new ProtocolItem { Header = "Motor", Summary = "Topplocket sprucket", ProtocolImageUri = "user_128.png", State = "Anmärkningar" });
this.protocolItems.Add(new ProtocolItem { Header = "Lysen", Summary = "Felvinklat halvljus", ProtocolImageUri = "user_128.png", State = "Anmärkningar" });
this.protocolItems.Add(new ProtocolItem { Header = "Kylare", Summary = "Läckande kylare", ProtocolImageUri = "user_128.png", State = "Anmärkningar" });
}
}
上的任何建議，就如何解決這個問題？如果從集合添加或刪除項目
最好的問候， 喬納斯
你已經在那裏發佈了很多代碼，但是從你的問題中不清楚它究竟是什麼不工作。你能澄清嗎？ –
實際上，如果我仍然在視圖中更新viewmodel中可觀察集合中的任何項目時，我的視圖會更新。但是，如果我從另一個視圖更新視圖模型，則在我的手機上回擊沒有任何反應。我究竟做錯了什麼？ –
您是否在更新集合或集合中的項目？ – chustar