首先,抱歉我的英语不好。 我正在使用Xamarin.Form开发iOS和Android项目。
我想要一个可重复使用的“xaml用户控件”,并且我需要使用ICommand使其可点击。
这是StackLayoutButton组件:
<?xml version="1.0" encoding="utf-8" ?>
<StackLayout xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="Installa.Controls.StackLayoutButton">
<Image x:Name="Icon" Source="{Binding Icon}" />
<Label x:Name="Text" Text="{Binding Title}" HorizontalOptions="Center" LineBreakMode="NoWrap" Font="Small" TextColor="Red" />
</StackLayout>
这是 CalendarioPage xaml 页面,组件被使用在该页面上。
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:controls="clr-namespace:Installa.Controls;assembly=Installa"
x:Class="Installa.CalendarioPage">
<StackLayout>
<Label Text="{Binding ViewName}" Font="42" IsVisible="{Binding IsWindowsPhone}" />
<ActivityIndicator IsRunning="{Binding IsLoading}" IsVisible="{Binding IsLoading}" Color="Red" />
<controls:StackLayoutButton BindingContext="{Binding Blog}" TextColor="Blue" /> <!-- Command="{Binding SubmitCommand}" -->
<controls:StackLayoutButton BindingContext="{Binding Facebook}" TextColor="Red" /> <!-- Command="{Binding SubmitCommand}" -->
</StackLayout>
</ContentPage>
这是CalendarioPage的C#页面:
public partial class CalendarioPage : ContentPage
{
private CalendarioViewModel vm;
public CalendarioPage()
{
InitializeComponent();
vm = new CalendarioViewModel();
this.BindingContext = vm;
}
}
这是ViewModel类:
namespace Installa
{
public class CalendarioViewModel: BaseViewModel
{
public CalendarioViewModel()
{
blog = new Activity();
blog.Link = "www.google.it";
blog.Title = "Titolo del blog";
blog.Icon = "logomenu.png";
facebook = new Activity();
facebook.Title = "Tito Fbook";
facebook.Link = "www.facebook.it";
facebook.Icon = "icon.png";
ViewName = "nome della view";
IsLoading = false;
}
Activity blog = null;
public Activity Blog
{
get {return blog;}
}
Activity facebook = null;
public Activity Facebook
{
get { return facebook; }
}
string viewName = string.Empty;
public string ViewName
{
get { return viewName; }
set { SetProperty(ref viewName, value); }
}
public bool IsWindowsPhone
{
get
{
return Device.OS == TargetPlatform.WinPhone;
}
}
bool isLoading = false;
public bool IsLoading
{
get { return isLoading; }
set { SetProperty(ref isLoading, value); }
}
}
}
使用Activity这个简单的类:
public string Title { get; set; }
public string Link { get; set; }
public String Icon { get; set; }
到目前为止,所有的东西都正常工作,但现在我需要实现ICommand接口。
在StackLayoutButton的c#代码中,我尝试添加:
var tapGestureRecognizer = new TapGestureRecognizer();
tapGestureRecognizer.SetBinding(TapGestureRecognizer.CommandProperty, "TapCommand");
Icon.GestureRecognizers.Add(tapGestureRecognizer)
Text.GestureRecognizers.Add(tapGestureRecognizer)
此外,我尝试将INotifyPropertyChanged和'OnTapped'方法添加到CalendarioViewModel中。
在Activity.cs中,我添加了'ICommand tapCommand'和相关的get...但是它没有起作用。
我尝试了其他方法,但是我无法启用StackLayoutButton组件上的点击。
我应该如何做呢?例如,我想要一个可编程的命令...例如,我想要浏览'Activity'的链接属性或能够打开新视图。
谢谢帮助!
更新:
我已经成功将TapGestureRecognizer添加到xaml用户控件(StackLayoutButton.xaml.cs)中,但我想以MVVM方式实现它。
using Xamarin.Forms;
namespace Installa.Controls
{
public partial class StackLayoutButton : StackLayout
{
public StackLayoutButton()
{
InitializeComponent();
TapGestureRecognizer tapGestureRecognizer = new TapGestureRecognizer
{
Command = new Command(OnMyComponentTapped),
CommandParameter = "ciao"
};
this.Icon.GestureRecognizers.Add(tapGestureRecognizer);
this.Text.GestureRecognizers.Add(tapGestureRecognizer);
}
async void OnMyComponentTapped(object parameter)
{
// do action
}
public Color TextColor
{
get { return this.Text.TextColor; }
set { this.Text.TextColor = value; }
}
public Label TextControl
{
get { return this.Text; }
set { this.Text = value; }
}
}
}
有人能给我提供建议吗?
谢谢