Question

尝试从MasterDetail菜单启动设置页面时出现错误var all_checked = new Array(); function add_checked(el) { all_checked.push(el.id); }。从研究中我知道，这意味着无法实例化该页面。这是页面的<form action="/action_page.php"> <table id="t01" width="1200" height="10" border="3"> <tbody> <tr><th>DETAILS</th> <th>OK</th> <th>FIXED</th> <th>INCOMPLETE</th> <th>N/A</th> <th>NOTES</th> </tr> <tr> <td><b>MOTOR & REDUCER-</b>Are correct and installed properly.</td> <td><input name="INS1" id="CHK22" onclick="ckChange(this)" type="checkbox"><br></form></td> <td><input name="INS1" id="CHK23" onclick="ckChange(this)" type="checkbox"><br></td> <td><input name="INS1" id="CHK24" onclick="ckChange(this)" type="checkbox"><br></td> <td><input name="INS1" id="CHK25" onclick="ckChange(this);add_checked(this)" type="checkbox"><br></td> <td width="15%"> <textarea placeholder="Type notes and remarks." cols="55"></textarea> </td> </tr> <tr> <td><b>REDUCER LUBRICATION-</b>Reducer is filled with oil (Mobil SHC 634/ISO VG 460)(ISS 0.7).</td> <td><input name="INS2" id="CHK26" onclick="ckChange(this)" type="checkbox"><br></form></td> <td><input name="INS2" id="CHK27" onclick="ckChange(this)" type="checkbox"><br></td> <td><input name="INS2" id="CHK28" onclick="ckChange(this)" type="checkbox"><br></td> <td><input name="INS2" id="CHK29" onclick="ckChange(this);add_checked(this)" type="checkbox"><br></td> <td> <textarea placeholder="Type notes and remarks." cols="55"></textarea> </td> </tr> </table> </form>。

我正在使用James Montenegro的System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation存储设置。

xaml

这是背后的代码

xam.plugins.settings

和ViewModel

    <?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="EIOBoardMobile.Views.SettingsPage"
                         Title="Settings">
    <ContentPage.Content>
        <StackLayout>
            <Label Text="Connection Information" />
            <StackLayout>
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="*" />
                        <RowDefinition Height="*" />
                        <RowDefinition Height="*" />
                        <RowDefinition Height="*" />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <StackLayout Orientation="Vertical" Grid.Row="0" Grid.Column="0"  >
                        <StackLayout.GestureRecognizers>
                            <TapGestureRecognizer 
                                            Tapped="OnServerTapped" 
                                                NumberOfTapsRequired="1" />
                        </StackLayout.GestureRecognizers>
                        <Label Text="Server name" />
                        <Label x:Name="Server" Text="{Binding Connection}" />
                    </StackLayout>
                    <Label Text="{Binding UserName}" Grid.Row="1" Grid.Column="0"/>
                    <Label Text="{Binding Password}" Grid.Row="2" Grid.Column="0"/>
                    <StackLayout Orientation="Vertical" Grid.Row="3" Grid.Column="0" >
                        <Label Text="Test Connection" />
                        <Label Text="Click to test your connection settings" />
                    </StackLayout>
                </Grid>
                <Label Text="Location" />
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="*" />
                        <RowDefinition Height="*" />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="***" />
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <Label Text="Location Tracking" Grid.Row="0" Grid.Column="0" />
                    <Switch IsToggled="{Binding LocationTracking}" Grid.Row="0" Grid.Column="1" />
                    <StackLayout Orientation="Vertical" Grid.Row="1" Grid.Column="0">
                        <Label Text="Location Caching" />
                        <Label Text="WARNING! Experimental! Stores location data while offline." />
                    </StackLayout>
                    <Switch IsToggled="{Binding LocationCaching}" Grid.Row="1" Grid.Column="1" />
                </Grid>
                <Label Text="Logging Options" />
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="*" />
                        <RowDefinition Height="*" />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="***" />
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <StackLayout Orientation="Vertical" Grid.Row="0" Grid.Column="0">
                        <Label Text="Allow Logging" />
                        <Label Text="Collecting crash data" />
                    </StackLayout>
                    <Switch IsToggled="{Binding AllowLogging}" Grid.Row="0" Grid.Column="1" />
                    <StackLayout Orientation="Vertical" Grid.Row="1" Grid.Column="0">
                        <Label Text="Crash log email" />
                        <Label Text="Provide us an email to contact you regarding crash logs" />
                    </StackLayout>
                </Grid>
                <Label Text="Caching Options" />
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="*" />
                        <RowDefinition Height="*" />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="***" />
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <StackLayout Orientation="Vertical" Grid.Row="0" Grid.Column="0">
                        <Label Text="Caching" />
                        <Label Text="CacheSize:" />
                    </StackLayout>
                    <Switch IsToggled="{Binding Caching}" Grid.Row="0" Grid.Column="1" />
                    <StackLayout Orientation="Vertical" Grid.Row="1" Grid.Column="0">
                        <Label Text="Delete Cache" />
                        <Label Text="Click to delete the application cache" />
                    </StackLayout>
                </Grid>
                <Label Text="Updates" />
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="*" />
                        <RowDefinition Height="*" />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="***" />
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <Label Text="Notify me of new updates" Grid.Row="0" Grid.Column="0" />
                    <Switch IsToggled="{Binding UpdateNotify}" Grid.Row="0" Grid.Column="1" />
                    <Label Text="Check for updates" Grid.Row="1" Grid.Column="0" />
                </Grid>
            </StackLayout>
        </StackLayout>
    </ContentPage.Content>
</ContentPage>

知道我在做什么错吗？ IDE未显示任何错误。我尝试以2种或3种不同方式设置using EIOBoardMobile.ViewModel; using EIOBoardMobile.Views.popups; using Rg.Plugins.Popup.Extensions; using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using Xamarin.Forms; using Xamarin.Forms.Xaml; namespace EIOBoardMobile.Views { [XamlCompilation(XamlCompilationOptions.Compile)] public partial class SettingsPage : ContentPage { public SettingsPage () { InitializeComponent (); BindingContext = new SettingsPageViewModel(); } public async void OnServerTapped(object sender, EventArgs e) { await Navigation.PushPopupAsync(new ConnectionPopupPage()); } } }操作。我是否不能将using EIOBoardMobile.Helpers; using EIOBoardMobile.Model; using System; using System.Collections.Generic; using System.Collections.ObjectModel; using System.ComponentModel; using System.Runtime.CompilerServices; using System.Text; using System.Windows.Input; namespace EIOBoardMobile.ViewModel { public class SettingsPageViewModel : INotifyPropertyChanged { public ICommand ItemSelectedCommand { get; private set; } public SettingsPageViewModel() { } public void OnCreate() { } public string Connection { get { return Settings.ConnectionAddress; } set { Settings.ConnectionAddress = value; } } public string UserName { get { return Settings.UserName; } set { Settings.UserName = value; } } public string Password { get { return Settings.Password; } set { Settings.Password = value; } } public bool LocationTracking { get { return Settings.LocationTracking; } set { Settings.LocationTracking = value; } } public bool LocationCaching { get { return Settings.LocationCaching; } set { Settings.LocationCaching = value; } } public bool AllowLogging { get { return Settings.AllowLogging; } set { Settings.AllowLogging = value; } } public string CrashLogEmail { get { return Settings.CrashLogEmail; } set { Settings.CrashLogEmail = value; } } public bool Caching { get { return Settings.Caching; } set { Settings.Caching = value; } } public bool UpdateNotify { get { return Settings.UpdateNotify; } set { Settings.UpdateNotify = value; } } public event PropertyChangedEventHandler PropertyChanged; protected void RaisePropertyChanged( [CallerMemberName] string caller = "") { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(caller)); } } } }放在OnTapped内？任何帮助将不胜感激。

Answer 1

closest(4, 5) -- prints 5 closest(5.85, 5) -- prints 5 closest(52.4, 5) -- prints 50 closest(93.594664, 9) -- prints 90是GridUnitType：

绝对：将Value属性值解释为设备特定单位的数量。
自动：忽略Value属性值，并选择适合行或列子级的大小。
星号：将Value属性值解释为比例权重，在考虑到具有“绝对”或“自动”的行和列之后进行布局。

因此，根据Xamarin的XAML规则，这将无效：

Enum

这些是有效的：

<ColumnDefinition Width="***" />

您的XAML应该类似于：

<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="100" />

System.Reflection.TargetInvocationException将设置页面实例化为MasterDetail菜单中的导航页面

1 个答案: