Question

当我尝试在Visual Studio上运行该应用程序时，我遇到了一个例外。我正在尝试使用xamarin表单构建时间表，当有人单击相关性（“ Prioridade”的4个选项）时，它将时间表作为新事件保存。每当我尝试在仿真中尝试新的事情时，都会遇到相同的错误。以下是代码：

XAML

> new Date(new Date().setHours(0, 0, 0, 0))
2019-12-03T23:00:00.000Z

我遇到了大多数问题的C＃

    <?xml version="1.0" encoding="UTF-8"?>
<ContentPage
    xmlns ="http://xamarin.com/schemas/2014/forms"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    x:Class="XPerfilEMenu.Tarefas.Cadastro">
    <ContentPage.Content>
        <StackLayout Margin="40" Spacing="40">
            <Label FontAttributes="Bold" Text="Nome da tarefa" />
            <Entry x:Name="TarefaDigitada"/>
            <Label FontAttributes="Bold" Text="Prioridade da tarefa" />
            <StackLayout x:Name="SLPrioridades" Spacing="30">

                <!--URGENTE E IMPORTANTE-->
                    <StackLayout Spacing="10" Orientation="Horizontal">
                        <!--<Image Source="4.png"/>-->
                    <Image>
                        <Image.Source>
                            <OnPlatform
                                x:TypeArguments="FileImageSource">
                                <On
                                    Platform="iOS, Android"
                                    Value="Vermelho.png" />
                            </OnPlatform>
                        </Image.Source>
                    </Image>
                    <Label
                            Text="Urgente e importante"
                            TextColor="Gray"
                            HorizontalOptions="FillAndExpand" />

                    <StackLayout.GestureRecognizers>
                        <TapGestureRecognizer Tapped="PrioridadeEscolhida" />
                    </StackLayout.GestureRecognizers>

                    </StackLayout>

                <!--URGENTE E NÃO IMPORTANTE-->
                <StackLayout
                    Spacing="10"
                    Orientation="Horizontal">
                    <Image
                        Source="Laranja.png" />
                    <Label
                        Text="Urgente e não importante"
                        HorizontalOptions="FillAndExpand"
                        TextColor="Gray" />

                    <StackLayout.GestureRecognizers>
                        <TapGestureRecognizer
                            Tapped="PrioridadeEscolhida" />
                    </StackLayout.GestureRecognizers>
                </StackLayout>

                <!--NÃO URGENTE E IMPORTANTE-->
                <StackLayout
                    Spacing="10"
                    Orientation="Horizontal">
                    <Image
                        Source="Amarelo.png" />
                    <Label
                        Text="Não urgente e importante"
                        HorizontalOptions="FillAndExpand"
                        TextColor="Gray" />
                    <StackLayout.GestureRecognizers>
                        <TapGestureRecognizer
                            Tapped="PrioridadeEscolhida" />
                    </StackLayout.GestureRecognizers>
                </StackLayout>

                <!--NÃO URGENTE E NÃO IMPORTANTE-->
                <StackLayout
                    Spacing="10"
                    Orientation="Horizontal">
                    <Image
                        Source="Verde.png" />
                    <Label
                        Text="Não urgente e não importante"
                        HorizontalOptions="FillAndExpand"
                        TextColor="Gray" />
                    <StackLayout.GestureRecognizers>
                        <TapGestureRecognizer
                            Tapped="PrioridadeEscolhida" />
                    </StackLayout.GestureRecognizers>
                </StackLayout>

                <!-- ADICIONAR BOTÃO -->
                <Button HorizontalOptions="End" Margin="20" Clicked="AdicionarTarefa">
                    <Button.ImageSource>
                        <OnPlatform
                            x:TypeArguments="FileImageSource">
                            <On
                                Platform="iOS, Android"
                                Value="AddBotao.png" />
                        </OnPlatform>
                    </Button.ImageSource>
                </Button> 
            </StackLayout>
        </StackLayout>
    </ContentPage.Content>
</ContentPage>

Answer 1

为什么要遍历布局，这很繁琐且容易出错。

您可以使用属性：x:Name：例如：

               <Label
                    x:Name="LabelPrioridade"
                    Text="Urgente e não importante"
                    HorizontalOptions="FillAndExpand"
                    TextColor="Gray" />

像这样使用，非常简单：

   LabelPrioridade.TextColor = Color.Gray;

在Xamarin.Forms上执行计划作业

1 个答案: