C# 在Xamarin.Forms上的Salve计划作业_C#_Xamarin_Xamarin.forms_Schedule

C# 在Xamarin.Forms上的Salve计划作业

c# xamarin xamarin.forms

C# 在Xamarin.Forms上的Salve计划作业,c#,xamarin,xamarin.forms,schedule,C#,Xamarin,Xamarin.forms,Schedule,当我尝试在visual studio上运行应用程序时，出现了一个异常问题。我试图用xamarin表单建立一个时间表，当有人点击相关性（“Prioridade”的4个选项）时，它作为一个新的事件在时间表上得到了补救。每次我试图在模拟上做一件新的事情，我都会犯同样的错误。代码如下： XAML <?xml version="1.0" encoding="UTF-8"?> <ContentPage xmlns ="http://xamarin.com/schemas/2

当我尝试在visual studio上运行应用程序时，出现了一个异常问题。我试图用xamarin表单建立一个时间表，当有人点击相关性（“Prioridade”的4个选项）时，它作为一个新的事件在时间表上得到了补救。每次我试图在模拟上做一件新的事情，我都会犯同样的错误。代码如下：

XAML

    <?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>

为什么要遍历布局，它相当乏味而且容易出错

您可以使用属性：

x:Name

：例如：

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

为什么要遍历布局，它相当乏味而且容易出错

您可以使用属性：

x:Name

：例如：

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

“我也犯了同样的错误。”错误是什么？请发布您收到的错误/异常。System.InvalidCastException foi gerado Speciefied cast无效，并选择以下行：Label LabelPrioridade=（（StackLayout）Linha）.Children[1]作为标签；“我也犯了同样的错误。”错误是什么？请发布您收到的错误/异常。System.InvalidCastException foi gerado Speciefied cast无效，并选择以下行：Label LabelPrioridade=（（StackLayout）Linha）.Children[1]作为标签；

   LabelPrioridade.TextColor = Color.Gray;