我知道这里有一些类似的话题，但我无法从他们那里得到任何答案。我必须在我的 Windows Phone 7 应用程序中将网格的背景更新为图像或颜色。我使用我的值转换器执行此操作，它工作正常，但我必须重新加载集合，以便它更新颜色或图像。
<Grid Background="{Binding Converter={StaticResource ImageConverter}}" Width="125" Height="125" Margin="6">
转换器接收对象然后从中获取颜色和图像，这里是转换器
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
People myC = value as People;
string myImage = myC.Image;
object result = myC.TileColor;
if (myImage != null)
{
BitmapImage bi = new BitmapImage();
bi.CreateOptions = BitmapCreateOptions.BackgroundCreation;
ImageBrush imageBrush = new ImageBrush();
using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
{
if (myIsolatedStorage.FileExists(myImage))
{
using (
IsolatedStorageFileStream fileStream = myIsolatedStorage.OpenFile(myImage, FileMode.Open,
FileAccess.Read))
{
bi.SetSource(fileStream);
imageBrush.ImageSource = bi;
}
}
else
{
return result;
}
}
return imageBrush;
}
else
{
return result;
}
}
我需要以某种方式更新/刷新网格标签或值转换器，以便它可以显示最新的更改！
编辑
添加了更多代码
该模型 ：
[Table]
public class People : INotifyPropertyChanged, INotifyPropertyChanging
{
private int _peopleId;
[Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)]
public int PeopleId
{
get { return _peopleId; }
set
{
if (_peopleId != value)
{
NotifyPropertyChanging("PeopleId");
_peopleId = value;
NotifyPropertyChanged("PeopleId");
}
}
}
private string _peopleName;
[Column]
public string PeopleName
{
get { return _peopleName; }
set
{
if (_peopleName != value)
{
NotifyPropertyChanging("PeopleName");
_peopleName = value;
NotifyPropertyChanged("PeopleName");
}
}
}
private string _tileColor;
[Column]
public string TileColor
{
get { return _tileColor; }
set
{
if (_tileColor != value)
{
NotifyPropertyChanging("TileColor");
_tileColor = value;
NotifyPropertyChanged("TileColor");
}
}
}
private string _image;
[Column]
public string Image
{
get { return _image; }
set
{
if (_image != value)
{
NotifyPropertyChanging("Image");
_image = value;
NotifyPropertyChanged("Image");
}
}
}
[Column]
internal int _groupId;
private EntityRef<Groups> _group;
[Association(Storage = "_group", ThisKey = "_groupId", OtherKey = "Id", IsForeignKey = true)]
public Groups Group
{
get { return _group.Entity; }
set
{
NotifyPropertyChanging("Group");
_group.Entity = value;
if (value != null)
{
_groupId = value.Id;
}
NotifyPropertyChanging("Group");
}
}
[Column(IsVersion = true)]
private Binary _version;
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
#endregion
#region INotifyPropertyChanging Members
public event PropertyChangingEventHandler PropertyChanging;
private void NotifyPropertyChanging(string propertyName)
{
if (PropertyChanging != null)
{
PropertyChanging(this, new PropertyChangingEventArgs(propertyName));
}
}
#endregion
}
视图模型：
public class PeopleViewModel : INotifyPropertyChanged
{
private PeopleDataContext PeopleDB;
// Class constructor, create the data context object.
public PeopleViewModel(string PeopleDBConnectionString)
{
PeopleDB = new PeopleDataContext(PeopleDBConnectionString);
}
private ObservableCollection<People> _allPeople;
public ObservableCollection<People> AllPeople
{
get { return _allPeople; }
set
{
_allPeople = value;
NotifyPropertyChanged("AllPeople");
}
}
public ObservableCollection<People> LoadPeople(int gid)
{
var PeopleInDB = from People in PeopleDB.People
where People._groupId == gid
select People;
AllPeople = new ObservableCollection<People>(PeopleInDB);
return AllPeople;
}
public void updatePeople(int cid, string cname, string image, string tilecol)
{
People getc = PeopleDB.People.Single(c => c.PeopleId == cid);
getc.PeopleName = cname;
getc.Image = image;
getc.TileColor = tilecol;
PeopleDB.SubmitChanges();
}
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
#endregion
}
申请页面
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<ListBox Margin="0,8,0,0" x:Name="Peoplelist" HorizontalAlignment="Center" BorderThickness="4" ItemsSource="{Binding AllPeople}">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Background="{Binding Converter={StaticResource ImageConverter}}" Width="125" Height="125" Margin="6">
<TextBlock Name="name" Text="{Binding PeopleName}" VerticalAlignment="Center" HorizontalAlignment="Center" TextAlignment="Center" TextWrapping="Wrap"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<toolkit:WrapPanel/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
</Grid>
后面的应用程序页面代码
public partial class PeopleList : PhoneApplicationPage
{
private int gid;
private bool firstRun;
public PeopleList()
{
InitializeComponent();
firstRun = true;
this.DataContext = App.ViewModel;
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
gid = int.Parse(NavigationContext.QueryString["Id"]);
if (firstRun)
{
App.ViewModel.LoadPeople(gid);
firstRun = false;
}
}
}