public MessagePage()
{
MessageViewModel = new MessagePageViewModel();
this.InitializeComponent();
this.Loaded += MessagePage_Loaded;
// Always use the cached page
// this.NavigationCacheMode = NavigationCacheMode.Required;
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
if (model == null)
{
model = new MessagePageViewModel();
model.MessageId = Convert.ToInt32(NavigationContext.QueryString["id"]);
DataContext = model;
LoadMessage();
}
}
/// <summary>
/// Populates the page with content passed during navigation. Any saved state is also
/// provided when recreating a page from a prior session.
/// </summary>
/// <param name="sender">
/// The source of the event; typically <see cref="NavigationHelper" />
/// </param>
/// <param name="e">
/// Event data that provides both the navigation parameter passed to
/// <see cref="Frame.Navigate(Type, Object)" /> when this page was initially requested and
/// a dictionary of state preserved by this page during an earlier
/// session. The state will be null the first time a page is visited.
/// </param>
private void NavigationHelper_LoadState(object sender, LoadStateEventArgs e)
{
_vm = (MessagePageViewModel)DataContext;
if (e.PageState != null && e.PageState.ContainsKey("userEntity") && App.UserAccountEntity == null)
{
string savedStateJson = e.PageState["userAccountEntity"].ToString();
App.UserAccountEntity = JsonConvert.DeserializeObject <UserAccountEntity>(savedStateJson);
savedStateJson = e.PageState["userEntity"].ToString();
_user = JsonConvert.DeserializeObject <UserAccountEntity.User>(savedStateJson);
App.UserAccountEntity.SetUserEntity(_user);
}
var jsonObjectString = (string)e.NavigationParameter;
_messageGroup = JsonConvert.DeserializeObject <MessageGroupEntity.MessageGroup>(jsonObjectString);
_vm.SetMessages(_messageGroup.MessageGroupId, App.UserAccountEntity);
}
public MessagePage(MessagePageViewModel ViewModel)
{
InitializeComponent();
this.BindingContext = ViewModel;
}
public MessagePage()
{
Title = "Monkey Chat";
var _messagePageViewModel = new MessagePageViewModel();
var MessagesListView = new ListView()
{
BackgroundColor = Color.White,
VerticalOptions = LayoutOptions.FillAndExpand,
HorizontalOptions = LayoutOptions.FillAndExpand,
ItemTemplate = new MyDataTemplateSelector(),
ItemsSource = _messagePageViewModel.Messages,
HasUnevenRows = true,
SeparatorVisibility = SeparatorVisibility.None,
//SelectedItem = ""
};
var MessageEntry = new Entry()
{
Keyboard = Keyboard.Chat,
HeightRequest = 25,
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.CenterAndExpand,
};
MessageEntry.SetBinding(Entry.TextProperty, "OutGoingText");
var SentButton = new Button()
{
Text = "发送",
HorizontalOptions = LayoutOptions.CenterAndExpand,
VerticalOptions = LayoutOptions.CenterAndExpand,
Command = _messagePageViewModel.SendCommand
};
var MessageControls = new Grid()
{
Padding = 5,
BackgroundColor = Color.FromHex("efeff4"),
VerticalOptions = LayoutOptions.End,
HorizontalOptions = LayoutOptions.FillAndExpand,
RowDefinitions =
{
new RowDefinition {
Height = new GridLength(30, GridUnitType.Absolute)
}
},
ColumnDefinitions =
{
new ColumnDefinition {
Width = GridLength.Auto
},
new ColumnDefinition {
Width = new GridLength(100, GridUnitType.Absolute)
},
}
};
MessageControls.Children.Add(MessageEntry, 0, 0);
MessageControls.Children.Add(SentButton, 0, 1);
var ChatLayout = new StackLayout
{
Spacing = 0,
VerticalOptions = LayoutOptions.FillAndExpand,
Children =
{
MessagesListView,
MessageControls
}
};
Content = ChatLayout;
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
ViewModel = e.Parameter as MessagePageViewModel;
}
