在进行一些异步操作后,我想在控件中设置焦点SearchBox
,并且我想从我的ViewModel中进行。
我怎么可能做到这一点?
编辑
视图模型代码:
private bool _searchBarFocused;
public bool SearchBarFocused
{
get { return _searchBarFocused; }
set
{
_searchBarFocused = value;
base.OnPropertyChanged("SearchBarFocused");
}
}
public async Task InitializeData()
{
// Other operations...
SearchBarFocused = true;
}
View 的代码隐藏代码:
protected override void OnAppearing()
{
base.OnAppearing();
(this.BindingContext as MyViewModel).InitializeData();
}
搜索栏 XAML 代码:
<SearchBar SearchCommand="{Binding SearchItemsCommand}">
<SearchBar.Triggers>
<DataTrigger TargetType="SearchBar"
Binding="{Binding SearchBarFocused, Mode=TwoWay}" Value="True">
<Trigger.EnterActions>
<triggers:SearchBarFocusTriggerAction Focused="True" />
</Trigger.EnterActions>
<Trigger.ExitActions>
<triggers:SearchBarFocusTriggerAction Focused="False" />
</Trigger.ExitActions>
</DataTrigger>
</SearchBar.Triggers>
</SearchBar>
触发动作代码:
public class SearchBarFocusTriggerAction : TriggerAction<SearchBar>
{
public bool Focused { get; set; }
protected override void Invoke(SearchBar searchBar)
{
if (Focused)
searchBar.Focus();
else
searchBar.Unfocus();
}
}