Xamarin 表单中的注册项目错误

Posted 2023-03-25

【中文标题】Xamarin 表单中的注册项目错误

【英文标题】：Registration project error in Xamarin forms

【发布时间】：2022-01-21 19:34:28

【问题描述】：

我是新来的，也是编码新手。我刚刚尝试了 YT 的这个小项目。我复制了所有内容，但无法弄清楚错误有什么问题。 （'x' 是一个未声明的前缀。）

提前致谢！

        <Grid Margin="20,0,20,0" VerticalOptions="CenterAndExpand">
            <Grid.RowDefinitions>
                <RowDefinition Height ="Auto"/>
                <RowDefinition Height ="Auto"/>
                <RowDefinition Height ="Auto"/>
                <RowDefinition Height ="Auto"/>
                <RowDefinition Height ="Auto"/>
            </Grid.RowDefinitions>

            <StackLayout Grid.Row ="0">
                <Entry Placeholder ="UserName" FontSize ="16" x:Name =" EntryUserName"/>

            </StackLayout>
            <StackLayout Grid.Row="1">
                <Entry Placeholder ="PassWord" IsPassword="true"  FontSize ="16" x:Name =" EntryUserPassword"/>
            </StackLayout>
            <StackLayout Grid.Row="2">
                <Entry Placeholder ="Email" FontSize ="16" x:Name =" EntryUserEmail"/>
            </StackLayout>
            <StackLayout Grid.Row="3">
                <Entry Placeholder ="PhoneNumber" FontSize ="16" x:Name =" EntryUserPhoneNumber"/>
            </StackLayout>
            <StackLayout Grid.Row="4">
                <Button Text="Register" HorizontalOptions="CenterAndExpand" WidthRequest="100" TextColor="White" BackgroundColor="Blue" Clicked="Handle_Clicked"/>
            </StackLayout>
        </Grid>

    </StackLayout>

【参考方案1】：

你的Entry的Name属性值以空格为前缀，不合理。

您可以将其替换为其他有效字符。

例如：

替换

        <StackLayout Grid.Row ="0">
            <Entry Placeholder ="UserName" FontSize ="16" x:Name =" EntryUserName"/>
        </StackLayout>

与：

             <StackLayout Grid.Row ="0">
                <Entry Placeholder ="UserName" FontSize ="16" x:Name ="mEntryUserName"   />
            </StackLayout>

其他条目的名称类似。

请参考以下代码：

    <StackLayout>
        <Grid Margin="20,0,20,0" VerticalOptions="CenterAndExpand"   >
            <Grid.RowDefinitions>
                <RowDefinition Height ="Auto"/>
                <RowDefinition Height ="Auto"/>
                <RowDefinition Height ="Auto"/>
                <RowDefinition Height ="Auto"/>
                <RowDefinition Height ="Auto"/>
            </Grid.RowDefinitions>

            <StackLayout Grid.Row ="0">
                <Entry Placeholder ="UserName" FontSize ="16" x:Name ="mEntryUserName"   />

            </StackLayout>
            <StackLayout Grid.Row="1">
                <Entry Placeholder ="PassWord" IsPassword="true"  FontSize ="16" x:Name ="mEntryUserPassword"/>
            </StackLayout>
            <StackLayout Grid.Row="2">
                <Entry Placeholder ="Email" FontSize ="16" x:Name ="mEntryUserEmail"/>
            </StackLayout>
            <StackLayout Grid.Row="3">
                <Entry Placeholder ="PhoneNumber" FontSize ="16" x:Name ="mEntryUserPhoneNumber"/>
            </StackLayout>
            <StackLayout Grid.Row="4">
                <Button Text="Register" HorizontalOptions="CenterAndExpand" WidthRequest="100" TextColor="White" BackgroundColor="Blue" Clicked="Button_Clicked"/>
            </StackLayout>
        </Grid>
    </StackLayout>

然后在YourPage.xaml.cs，你可以访问你在函数Button_Clicked中的入口，如下：

       private void Button_Clicked(object sender, EventArgs e)
    
        System.Diagnostics.Debug.WriteLine("User Name  is : " + mEntryUserName.Text +"<---> PassWord  is = " + mEntryUserPassword.Text);