如何使用 tapGesture (Xamarin.Forms) 从应用程序中的多个标签中删除选定的标签

Posted 2023-02-27

【中文标题】如何使用 tapGesture (Xamarin.Forms) 从应用程序中的多个标签中删除选定的标签

【英文标题】：how to delete a selected label from multiple labels in an application using tapGesture (Xamarin.Forms)

【发布时间】：2016-07-22 10:42:51

【问题描述】：

我有一个按钮，每次点击时都会创建一个标签，假设我点击了 10 次，所以现在我创建了 10 个标签。如何删除我点击的随机标签？

PS: my labels are added to a stackLayout

我的应用程序的想法是创建一个待办事项列表。我有一个输入框和一个按钮。我在输入框中输入我想要执行的操作，然后单击按钮并创建一个标签，我刚刚输入该标签。当我完成某件事后，我想点击特定标签并将其删除，这怎么可能。有什么帮助吗？

代码：

var entry = new Entry();
entry.Placeholder = "type here";
entry.BackgroundColor = Color.White;
entry.PlaceholderColor = Color.Gray;
var newButton = new Button  Text = "+", BackgroundColor = Color.Purple, FontSize = Device.GetNamedSize(NamedSize.Small, typeof(Button)), ;
StackLayout stackLayout = new StackLayout();
stackLayout.Children.Add(entry);
stackLayout.Children.Add(newButton);
this.Content = stackLayout;

var tapGestureRecognizer = new TapGestureRecognizer();
tapGestureRecognizer.Tapped += labelClick;
newButton.Clicked += (sender, args) =>  label = new Label();
label.BackgroundColor = Color.White;
label.TextColor = Color.Black;
label.Text = entry.Text;
entry.Text = "";
stackLayout.Children.Add(label);
label.GestureRecognizers.Add(tapGestureRecognizer);    

【问题讨论】：

拜托，你能添加一些你迄今为止尝试过的代码示例吗？

var entry = new Entry(); entry.Placeholder = "在这里输入"; entry.BackgroundColor = 颜色.白色； entry.PlaceholderColor = 颜色.灰色； var newButton = new Button Text = "+", BackgroundColor = Color.Purple, FontSize = Device.GetNamedSize(NamedSize.Small, typeof(Button)), ; StackLayout stackLayout = new StackLayout(); stackLayout.Children.Add(entry); stackLayout.Children.Add(newButton); this.Content = stackLayout;

var tapGestureRecognizer = new TapGestureRecognizer(); tapGestureRecognizer.Tapped += labelClick; newButton.Clicked += (sender, args) => label = new Label(); label.BackgroundColor = 颜色.白色； label.TextColor = 颜色.黑色；标签.Text = entry.Text; entry.Text = ""; stackLayout.Children.Add(标签);标签.GestureRecognizers.Add(tapGestureRecognizer); ;

【参考方案1】：

嗯，我不知道你的代码是怎样的，这使得回答你的问题有点困难，但这里有一个想法：

如果您使用的是 MVVM 方法（我推荐），您可以使用此标签创建一个视图，将其绑定到具有待办事项数据（Id、名称、详细信息...）的 ViewModel，添加 TapGesture并在 ViewModel 中采取行动。

编辑：

不是最好的方法，也不是我会做的方法。但这是基于您的来源的解决方案：

    public MainPage()
    
        var entry = new Entry();
        entry.Placeholder = "type here";
        entry.BackgroundColor = Color.White;
        entry.PlaceholderColor = Color.Gray;
        var newButton = new Button  Text = "+", BackgroundColor = Color.Purple, FontSize = Device.GetNamedSize(NamedSize.Small, typeof(Button)), ;
        StackLayout stackLayout = new StackLayout();
        stackLayout.Children.Add(entry);
        stackLayout.Children.Add(newButton);
        this.Content = stackLayout;

        newButton.Clicked += (sender, args) =>
        
            var label = new Label();
            label.BackgroundColor = Color.White;
            label.TextColor = Color.Black;
            label.Text = entry.Text;
            entry.Text = "";
            stackLayout.Children.Add(label);

            var tapGestureRecognizer = new TapGestureRecognizer();
            tapGestureRecognizer.Tapped += (sensder, e) => DeleteLabel(stackLayout, label);

            label.GestureRecognizers.Add(tapGestureRecognizer);
        ;
    

    void DeleteLabel(StackLayout stackLayout, Label label)
    
        stackLayout.Children.Remove(label);
    

【讨论】：

var entry = new Entry(); entry.Placeholder = "在这里输入"; entry.BackgroundColor = 颜色.白色； entry.PlaceholderColor = 颜色.灰色； var newButton = new Button Text = "+", BackgroundColor = Color.Purple, FontSize = Device.GetNamedSize(NamedSize.Small, typeof(Button)), ;

StackLayout stackLayout = new StackLayout(); stackLayout.Children.Add(frame1); stackLayout.Children.Add(entry); stackLayout.Children.Add(newButton); this.Content = stackLayout;

var tapGestureRecognizer = new TapGestureRecognizer(); tapGestureRecognizer.Tapped += labelClick;

newButton.Clicked += (sender, args) => label = new Label(); label.BackgroundColor = 颜色.白色； label.TextColor = 颜色.黑色；标签.Text = entry.Text; entry.Text = ""; stackLayout.Children.Add(标签);标签.GestureRecognizers.Add(tapGestureRecognizer); ;

@Rémy 看看我提出的解决方案。