Xaml 如何将ContentView中的CommandParameter绑定到Xamarin表单中父ContentPage中的元素_Xaml_Xamarin.forms

Xaml 如何将ContentView中的CommandParameter绑定到Xamarin表单中父ContentPage中的元素

xaml xamarin.forms

Xaml 如何将ContentView中的CommandParameter绑定到Xamarin表单中父ContentPage中的元素,xaml,xamarin.forms,Xaml,Xamarin.forms,我有一个父ContentPage，在单独的文件中有几个ContentView。我试图将父ContentView中的一个元素作为引用传递给其中一个视图中的CommandParameter，下面是我迄今为止的代码这是父内容页 <?xml version="1.0" encoding="utf-8" ?> <ContentPage x:Class="Acies.NitroT.Views.Shop.RefillPage" x

我有一个父ContentPage，在单独的文件中有几个ContentView。我试图将父ContentView中的一个元素作为引用传递给其中一个视图中的CommandParameter，下面是我迄今为止的代码

这是父内容页

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage
x:Class="Acies.NitroT.Views.Shop.RefillPage"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:base="clr-namespace:Acies.NitroT.ViewModels.Base;assembly=Acies.NitroT.Mobile.Shared"
xmlns:behaviors="clr-namespace:Acies.NitroT.Behaviors;assembly=Acies.NitroT.Mobile.Shared"
xmlns:control="clr-namespace:Acies.NitroT.Controls"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:homeViews="clr-namespace:Acies.NitroT.Views.Home"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:tab="clr-namespace:Syncfusion.XForms.TabView;assembly=Syncfusion.SfTabView.XForms"
xmlns:transViews="clr-namespace:Acies.NitroT.Views.Transaction"
Title="Gas Refill"
Padding="0"
base:ViewManager.AutoWireViewModel="true"
BackgroundColor="{DynamicResource Gray-White}"
NavigationPage.HasNavigationBar="False"
Visual="Material"
mc:Ignorable="d">
<ContentPage.Content>
    <RelativeLayout Padding="0">
        <RelativeLayout.Margin>
            <OnPlatform x:TypeArguments="Thickness">
                <On Platform="iOS" Value="0, 40, 0, 0" />
            </OnPlatform>
        </RelativeLayout.Margin>
        <Grid
            Padding="0"
            RelativeLayout.HeightConstraint="{ConstraintExpression Type=RelativeToParent,
                                                                   Property=Height,
                                                                   Factor=1}"
            RowSpacing="0"
            VerticalOptions="FillAndExpand">
            <Grid.RowDefinitions>
                <RowDefinition Height="auto" />
                <RowDefinition Height="*" />
                <RowDefinition Height="auto" />
            </Grid.RowDefinitions>

            <!--#region Google Map [Row:0] Pins="{Binding Pins}"-->
            <control:GoogleMapView
                x:Name="Map"
                Grid.Row="0"
                Grid.RowSpan="2"
                Margin="0"
                Padding="0"
                HorizontalOptions="FillAndExpand"
                VerticalOptions="FillAndExpand" />
            <!--#endregion-->

            <!--#region Search Control [Row:1]-->
            <Grid
                Grid.Row="1"
                Margin="20"
                VerticalOptions="Start">

                <Grid.RowDefinitions>
                    <RowDefinition Height="*" />
                    <RowDefinition Height="auto" />
                    <RowDefinition Height="auto" />
                </Grid.RowDefinitions>

                <!--#region Search Bar-->
                <homeViews:SearchBarView Grid.Row="0" Padding="0" />
                <!--#endregion-->

                <!--#region Chip Group-->
                <homeViews:AddressChipView Grid.Row="1" />
                <!--#endregion-->

                <!--#region Search Results View-->
                <homeViews:SearchResultsView Grid.Row="2" Padding="0" />
                <!--#endregion-->
            </Grid>
            <!--#endregion-->

            <!--#region Bottom Control [Row:2]-->
            
            <homeViews:CommandButtonsView
                Grid.Row="1"
                Margin="0,0,0,10"
                VerticalOptions="End" />
            <!--#endregion-->
        </Grid>
    </RelativeLayout>
</ContentPage.Content>

<?xml version="1.0" encoding="UTF-8" ?>
<ContentView
x:Class="Acies.NitroT.Views.Home.AddressChipView"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:behaviors="clr-namespace:Acies.NitroT.Behaviors"
xmlns:buttons="clr-namespace:Syncfusion.XForms.Buttons;assembly=Syncfusion.Buttons.XForms"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:controls="clr-namespace:Acies.NitroT.Controls;assembly=Acies.NitroT.Mobile.Shared"
mc:Ignorable="d"

x:Name="ChipView" // set the name of AddressChipView

>

上面的代码给出了以下错误：

09-29 10:52:19.447 I/MonoDroid(25814): UNHANDLED EXCEPTION:
09-29 10:52:19.449 I/MonoDroid(25814): System.InvalidOperationException: Operation is not valid due to the current state of the object.
09-29 10:52:19.449 I/MonoDroid(25814):   at Xamarin.Forms.Binding.ApplyRelativeSourceBinding (Xamarin.Forms.BindableObject targetObject, Xamarin.Forms.BindableProperty targetProperty) [0x00041] in D:\a\1\s\Xamarin.Forms.Core\Binding.cs:153 
09-29 10:52:19.449 I/MonoDroid(25814):   at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__7_0 (System.Object state) [0x00000] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1021 
09-29 10:52:19.449 I/MonoDroid(25814):   at Android.App.SyncContext+<>c__DisplayClass2_0.<Post>b__0 () [0x00000] in <7d2292394f8c488b97f5bc2a0ac0240d>:0 
09-29 10:52:19.449 I/MonoDroid(25814):   at Java.Lang.Thread+RunnableImplementor.Run () [0x00008] in <7d2292394f8c488b97f5bc2a0ac0240d>:0 
09-29 10:52:19.449 I/MonoDroid(25814):   at Java.Lang.IRunnableInvoker.n_Run (System.IntPtr jnienv, System.IntPtr native__this) [0x00008] in <7d2292394f8c488b97f5bc2a0ac0240d>:0 
09-29 10:52:19.449 I/MonoDroid(25814):   at (wrapper dynamic-method) Android.Runtime.DynamicMethodNameCounter.1(intptr,intptr)

09-29 10:52:19.447 I/MonoDroid（25814）：未处理的异常：
09-29 10:52:19.449 I/MonoDroid（25814）：System.InvalidOperationException:由于对象的当前状态，操作无效。
09-29 10:52:19.449 I/MonoDroid（25814）：位于Xamarin.Forms.Binding.ApplyRelativeSourceBinding（Xamarin.Forms.BindableObject targetObject，Xamarin.Forms.BindableProperty targetProperty）[0x00041]，位于D:\a\1\s\Xamarin.Forms.Core\Binding.cs:153
09-29 10:52:19.449 I/MonoDroid（25814）：在/Users/builder/jenkins/workspace/archive mono/2020-02/android/release/mcs/class/referencesource/mscorlib/System/Runtime/CompilerServices/asynchmethodbuilder.cs:1021中的System/Runtime/CompilerServices/Asynchmethod
09-29 10:52:19.449 I/MonoDroid（25814）：在Android.App.SyncContext+c_uuudisplayClass2_0.b_uu0（）[0x00000]in:0
09-29 10:52:19.449 I/MonoDroid（25814）：在Java.Lang.Thread+RunnableImplementor.Run（）[0x00008]中：0
09-29 10:52:19.449 I/MonoDroid（25814）：在Java.Lang.IRunnableInvoker.n_运行（System.IntPtr jnienv，System.IntPtr native_uuthis）[0x00008]in:0
09-29 10:52:19.449 I/MonoDroid（25814）：at（包装器动态方法）Android.Runtime.DynamicMethodNameCounter.1（intptr，intptr）

如何实现所需的结果。

您可以检查以下代码

在AddressChipView.xaml中由于您使用了自定义ContentView，因此需要在ContentView和父ContentPage中的元素之间使用绑定值

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage
x:Class="Acies.NitroT.Views.Shop.RefillPage"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:base="clr-namespace:Acies.NitroT.ViewModels.Base;assembly=Acies.NitroT.Mobile.Shared"
xmlns:behaviors="clr-namespace:Acies.NitroT.Behaviors;assembly=Acies.NitroT.Mobile.Shared"
xmlns:control="clr-namespace:Acies.NitroT.Controls"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:homeViews="clr-namespace:Acies.NitroT.Views.Home"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:tab="clr-namespace:Syncfusion.XForms.TabView;assembly=Syncfusion.SfTabView.XForms"
xmlns:transViews="clr-namespace:Acies.NitroT.Views.Transaction"
Title="Gas Refill"
Padding="0"
base:ViewManager.AutoWireViewModel="true"
BackgroundColor="{DynamicResource Gray-White}"
NavigationPage.HasNavigationBar="False"
Visual="Material"
mc:Ignorable="d">
<ContentPage.Content>
    <RelativeLayout Padding="0">
        <RelativeLayout.Margin>
            <OnPlatform x:TypeArguments="Thickness">
                <On Platform="iOS" Value="0, 40, 0, 0" />
            </OnPlatform>
        </RelativeLayout.Margin>
        <Grid
            Padding="0"
            RelativeLayout.HeightConstraint="{ConstraintExpression Type=RelativeToParent,
                                                                   Property=Height,
                                                                   Factor=1}"
            RowSpacing="0"
            VerticalOptions="FillAndExpand">
            <Grid.RowDefinitions>
                <RowDefinition Height="auto" />
                <RowDefinition Height="*" />
                <RowDefinition Height="auto" />
            </Grid.RowDefinitions>

            <!--#region Google Map [Row:0] Pins="{Binding Pins}"-->
            <control:GoogleMapView
                x:Name="Map"
                Grid.Row="0"
                Grid.RowSpan="2"
                Margin="0"
                Padding="0"
                HorizontalOptions="FillAndExpand"
                VerticalOptions="FillAndExpand" />
            <!--#endregion-->

            <!--#region Search Control [Row:1]-->
            <Grid
                Grid.Row="1"
                Margin="20"
                VerticalOptions="Start">

                <Grid.RowDefinitions>
                    <RowDefinition Height="*" />
                    <RowDefinition Height="auto" />
                    <RowDefinition Height="auto" />
                </Grid.RowDefinitions>

                <!--#region Search Bar-->
                <homeViews:SearchBarView Grid.Row="0" Padding="0" />
                <!--#endregion-->

                <!--#region Chip Group-->
                <homeViews:AddressChipView Grid.Row="1" />
                <!--#endregion-->

                <!--#region Search Results View-->
                <homeViews:SearchResultsView Grid.Row="2" Padding="0" />
                <!--#endregion-->
            </Grid>
            <!--#endregion-->

            <!--#region Bottom Control [Row:2]-->
            
            <homeViews:CommandButtonsView
                Grid.Row="1"
                Margin="0,0,0,10"
                VerticalOptions="End" />
            <!--#endregion-->
        </Grid>
    </RelativeLayout>
</ContentPage.Content>

<?xml version="1.0" encoding="UTF-8" ?>
<ContentView
x:Class="Acies.NitroT.Views.Home.AddressChipView"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:behaviors="clr-namespace:Acies.NitroT.Behaviors"
xmlns:buttons="clr-namespace:Syncfusion.XForms.Buttons;assembly=Syncfusion.Buttons.XForms"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:controls="clr-namespace:Acies.NitroT.Controls;assembly=Acies.NitroT.Mobile.Shared"
mc:Ignorable="d"

x:Name="ChipView" // set the name of AddressChipView

>

现在您可以在ContentPage中绑定它了

<homeViews:AddressChipView Grid.Row="1"  AddressSelectionChangedCommand={Binding xxxCommand}  CurrentMapView = {Binding Source={x:Reference Map}, Path=.} />

嗨，是的，成功了。谢谢这很有效！问题，如何更改从ContentView发送回ContentPage的CommandParameter？我尝试将propertychanged:添加到BindableProperty声明的末尾，但这不起作用。需要明确的是，CommandParameter按原样工作，但我想在返回之前在ContentView.xamal.cs页面中将其修改为不同的模型。

<homeViews:AddressChipView Grid.Row="1"  AddressSelectionChangedCommand={Binding xxxCommand}  CurrentMapView = {Binding Source={x:Reference Map}, Path=.} />