使用 MVVM 的 Metro Flyout [英] Metro Flyouts with MVVM

问题描述

我正在尝试在我的应用程序中使用 MahApps.Metro 的 Flyouts.所以我将这部分添加到我的 MainWindow.xaml 中:

I'm trying to use the Flyouts from MahApps.Metro in my application. So I added this part to my MainWindow.xaml:

<controls:MetroWindow.Flyouts>
    <controls:FlyoutsControl ItemsSource="{Binding Flyouts}">
        <controls:FlyoutsControl.ItemTemplate>
            <DataTemplate DataType="{x:Type viewModel:SettingsViewModel}">
                <view:SettingsFlyout/>
            </DataTemplate>
        </controls:FlyoutsControl.ItemTemplate>
    </controls:FlyoutsControl>
</controls:MetroWindow.Flyouts>

ItemTemplate 将包含从我的视图模型到视图的映射.Flyouts 是一个 ObservableCollection，目前只包含我的 SettingsViewModel.

The ItemTemplate will contain the mappings from my viewmodels to the views. Flyouts is an ObservableCollection<IFlyoutViewModel> and currently only contains my SettingsViewModel.

IFlyoutViewModel 定义:

using System.ComponentModel;

namespace MyApplication.ViewModel
{
    internal interface IFlyoutViewModel : INotifyPropertyChanged
    {
        bool Visible { get; set; }
    }
}

以及我如何使用 Visible 属性:

And how I use the Visible-property:

<controls:Flyout x:Class="MyApplication.View.SettingsFlyout"
                 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                 xmlns:controls="http://metro.mahapps.com/winfx/xaml/controls"
                 Header="Settings"
                 Position="Right"
                 IsOpen="{Binding Visible}"
                 Width="300">
    ...
</controls:Flyout>

所以现在我设置了 SettingsViewModel 的 Visible 属性，但是 Flyout 不会打开.我做错了什么?

So now I set the Visible-property of my SettingsViewModel, but the Flyout won't open. What am I doing wrong?

我只是尝试分配 IsOpen="true" 硬编码，但这也不起作用.所以用数据模板显示弹出窗口似乎是问题...

I just tried to assign IsOpen="true" hardcoded but this didn't work, too. So displaying the flyout with a datatemplate seems to be the problem...

推荐答案

我按照 Eldho 链接的问题讨论中的描述构建了它，现在它可以工作了.关键是要定义ItemContainerStyle 并在那里绑定IsOpen！

I built it like described in the issue dicussion linked by Eldho, now it works. The key ist to define ItemContainerStyle and bind IsOpen there!

新的MainWindow.xaml:

<controls:MetroWindow.Flyouts>
    <controls:FlyoutsControl ItemsSource="{Binding Flyouts}">
        <controls:FlyoutsControl.Resources>
            <view:FlyoutPositionConverter x:Key="FlyoutPositionConverter"/>
        </controls:FlyoutsControl.Resources>
        <controls:FlyoutsControl.ItemTemplate>
            <DataTemplate DataType="{x:Type viewModel:SettingsViewModel}">
                <view:SettingsFlyout/>
            </DataTemplate>
        </controls:FlyoutsControl.ItemTemplate>
        <controls:FlyoutsControl.ItemContainerStyle>
            <Style BasedOn="{StaticResource {x:Type controls:Flyout}}"
               TargetType="{x:Type controls:Flyout}">
                <Setter Property="Header"
                    Value="{Binding Header}" />
                <Setter Property="IsOpen"
                    Value="{Binding Visible}" />
                <Setter Property="Position"
                    Value="{Binding Position, Converter={StaticResource FlyoutPositionConverter}}" />
                <Setter Property="IsModal"
                    Value="{Binding IsModal}" />
                <Setter Property="Theme" Value="Accent" />
            </Style>
        </controls:FlyoutsControl.ItemContainerStyle>
    </controls:FlyoutsControl>
</controls:MetroWindow.Flyouts>

新的IFlyoutViewModel:

using System.ComponentModel;

namespace MyApplication.ViewModel
{
    internal interface IFlyoutViewModel : INotifyPropertyChanged
    {
        string Header { get; }
        bool Visible { get; set; }
        Position Position { get; set; }
        bool IsModal { get; set; }
    }

    public enum Position
    {
        Top,
        Left,
        Right,
        Bottom
    }
}

FlyoutPositionConverter 只是我的位置枚举和 MahApps.Metro.Controls.Position 之间的映射器，因为我不想在我的视图模型中使用真实的位置界面.

The FlyoutPositionConverter is just a mapper between my position enum and the MahApps.Metro.Controls.Position because I didn't want to use the real positon in my viewmodel interface.

此外，视图现在不再需要是 Flyout，它可以是普通的用户控件.

Also the view now no longer needs to be a Flyout, it can be a normal usercontrol.

这篇关于使用 MVVM 的 Metro Flyout的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！