XAML> ViewModel命令参数-无法从对象转换为布尔值? [英] XAML > ViewModel Command parameter - Cannot convert from object to bool?

问题描述

我有这个XAML

<Label.GestureRecognizers>
   <TapGestureRecognizer Command="{Binding TapGestureForUpdateCategories, Source={x:Reference MainPage}}" CommandParameter="false" />
</Label.GestureRecognizers>

以及此代码在我的ViewModel中

and this code in my ViewModel

public Command TapGestureForUpdateCategories => new Command(val =>
{
    App.DB.UpdateAllCategoryGroups(val);
    App.DB.UpdateAllCategory(val);
});

我正在尝试从XAML传递参数true或false，但是在命令C#代码中val下有一行，写着无法从对象转换为布尔值".有人可以帮我吗?

I am trying to pass the parameter true or false from the XAML but in the command C# code there is a line under val saying "Cannot convert from object to bool". Can anyone help me with this?

推荐答案

进行如下修改，我们可以通过TapGestureRecognizer.CommandParameter

Modify as below , we can define the type we want by x:type inside TapGestureRecognizer.CommandParameter

<Label.GestureRecognizers>
    <TapGestureRecognizer Command="{Binding TapGestureForUpdateCategories, Source={x:Reference MainPage}}">
        <TapGestureRecognizer.CommandParameter>
            <x:Boolean>True</x:Boolean>
        </TapGestureRecognizer.CommandParameter>
    </TapGestureRecognizer>
</Label.GestureRecognizers>

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