从代码访问DataTemplate的元素 [英] Access elements of a DataTemplate from code
本文介绍了从代码访问DataTemplate的元素的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想找到一种从c#访问 ButtonImage 元素的方法.不能从c#调用 DataTemplate 中包含的所有内容.
I would like to find a way to access the ButtonImage element from c#. Everything contained in the DataTemplate is not callable from c#.
<CarouselView
x:Name="FrasiView"
RelativeLayout.WidthConstraint="{ConstraintExpression
Type=RelativeToParent,
Property=Width,
Factor=1}"
RelativeLayout.YConstraint="{ConstraintExpression
Type=Constant,
Constant=45}"
PeekAreaInsets="18"
HeightRequest="370">
<CarouselView.ItemsLayout>
<LinearItemsLayout Orientation="Horizontal" SnapPointsType="MandatorySingle" SnapPointsAlignment="Center"/>
</CarouselView.ItemsLayout>
<CarouselView.ItemTemplate>
<DataTemplate>
<RelativeLayout>
<RelativeLayout x:Name="FrontView">
<RelativeLayout.GestureRecognizers>
<TapGestureRecognizer Tapped="FlipToBack_Tapped"/>
</RelativeLayout.GestureRecognizers>
<ImageButton
x:Name="CuoreVuoto"
RelativeLayout.YConstraint="{ConstraintExpression
Type=Constant,
Constant=22}"
RelativeLayout.XConstraint="{ConstraintExpression
Type=Constant,
Constant=275}"
Source="IconHeart"
WidthRequest="24"
Clicked="CuoreVuoto_Clicked"
BackgroundColor="Transparent"/>
<ImageButton
x:Name="CuorePieno"
RelativeLayout.YConstraint="{ConstraintExpression
Type=Constant,
Constant=22}"
RelativeLayout.XConstraint="{ConstraintExpression
Type=Constant,
Constant=275}"
Source="IconHeart"
WidthRequest="24"
Clicked="CuorePieno_Clicked"
IsVisible="False"
BackgroundColor="Transparent"/>
</RelativeLayout>
</RelativeLayout>
</DataTemplate>
</CarouselView.ItemTemplate>
</CarouselView>
在C#中，我想回想 CuorePieno 元素我该怎么办?
In c# I would like to recall the CuorePieno element
how could I do?
推荐答案
我希望当用户按下ImageButton时，IsVisible属性会更改
I would like that when the user presses on the ImageButton, the IsVisible property changes
我同意Jason的回复，您可以使用Binding更改ImageButton IsVisible属性，我做了一个示例，您可以看一下:
I agree with Jason's reply, you can use Binding to change ImageButton IsVisible property, I do one sample that you can take a look:
<RelativeLayout>
<CarouselView
x:Name="FrasiView"
HeightRequest="370"
ItemsSource="{Binding lists}"
PeekAreaInsets="18"
RelativeLayout.WidthConstraint="{ConstraintExpression Type=RelativeToParent,
Property=Width,
Factor=1}"
RelativeLayout.YConstraint="{ConstraintExpression Type=Constant,
Constant=45}">
<CarouselView.ItemsLayout>
<LinearItemsLayout
Orientation="Horizontal"
SnapPointsAlignment="Center"
SnapPointsType="MandatorySingle" />
</CarouselView.ItemsLayout>
<CarouselView.ItemTemplate>
<DataTemplate>
<RelativeLayout x:Name="FrontView">
<Label Text="{Binding str}" />
<ImageButton
x:Name="CuoreVuoto"
BackgroundColor="Transparent"
Clicked="CuoreVuoto_Clicked"
IsVisible="{Binding Vuoto}"
RelativeLayout.XConstraint="{ConstraintExpression Type=Constant,
Constant=275}"
RelativeLayout.YConstraint="{ConstraintExpression Type=Constant,
Constant=22}"
Source="c1.png"
WidthRequest="24" />
<ImageButton
x:Name="CuorePieno"
BackgroundColor="Transparent"
Clicked="CuorePieno_Clicked"
IsVisible="{Binding Pieno}"
RelativeLayout.XConstraint="{ConstraintExpression Type=Constant,
Constant=275}"
RelativeLayout.YConstraint="{ConstraintExpression Type=Constant,
Constant=22}"
Source="check.png"
WidthRequest="24" />
</RelativeLayout>
</DataTemplate>
</CarouselView.ItemTemplate>
</CarouselView>
</RelativeLayout>
隐藏代码
public partial class Page1 : ContentPage
{
public ObservableCollection<carouselmodel> lists { get; set; }
public Page1()
{
InitializeComponent();
lists = new ObservableCollection<carouselmodel>()
{
new carouselmodel(){str="test 1",Vuoto=true,Pieno=false},
new carouselmodel(){str="test 2",Vuoto=true,Pieno=false},
new carouselmodel(){str="test 3",Vuoto=true,Pieno=false},
new carouselmodel(){str="test 4",Vuoto=true,Pieno=false},
new carouselmodel(){str="test 5",Vuoto=true,Pieno=false},
new carouselmodel(){str="test 6",Vuoto=true,Pieno=false}
};
this.BindingContext = this;
}
private void CuoreVuoto_Clicked(object sender, EventArgs e)
{
var button = sender as ImageButton;
var model = button.BindingContext as carouselmodel;
if(model.Vuoto==true)
{
model.Vuoto = false;
model.Pieno = true;
}
}
private void CuorePieno_Clicked(object sender, EventArgs e)
{
var button = sender as ImageButton;
var model = button.BindingContext as carouselmodel;
if (model.Pieno == true)
{
model.Pieno = false;
model.Vuoto = true;
}
}
}
public class carouselmodel : ViewModelBase
{
public string str { get; set; }
private bool _Vuoto;
public bool Vuoto
{
get { return _Vuoto; }
set
{
_Vuoto = value;
RaisePropertyChanged("Vuoto");
}
}
private bool _Pieno;
public bool Pieno
{
get
{ return _Pieno; }
set
{
_Pieno = value;
RaisePropertyChanged("Pieno");
}
}
}
ViewModelBase类继承 INotifyPropertyChanged 接口，以更改原始数据.
The ViewModelBase class inherit INotifyPropertyChanged interface, to nofity data changed.
public class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public void RaisePropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
这篇关于从代码访问DataTemplate的元素的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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