c# - 在使用 ItemsSource 和帮助使用 Combo Box 之前，WPF Items 集合必须为空

Question

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="1.5*"/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>  



    <Grid Grid.Column="0" Background="DarkCyan">
        <Grid.ColumnDefinitions>
            <ColumnDefinition/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>    
            <ComboBox ItemsSource="{Binding Path=charList}" x:Name="comboBox" VerticalAlignment="Top" Width="Auto" Grid.ColumnSpan="2">
            <ComboBoxItem>
                <StackPanel Orientation="Horizontal">
                    <Image Source="Pictures\bagi_warrior.jpg" Width="100" Height="150"/>
                    <Grid>
                        <Grid.RowDefinitions>
                            <RowDefinition/>
                            <RowDefinition Height="6*"/>
                        </Grid.RowDefinitions>
                        <Label Grid.Row="0" Content="{Binding Path=Character.Name}" FontSize="30"/>
                        <Label Grid.Row="1" Content="{Binding Path=Character.Level}" FontSize="20"/>
                    </Grid>
                </StackPanel>
            </ComboBoxItem>
            <ComboBoxItem>
                <StackPanel Orientation="Horizontal">
                    <Image Source="Pictures\azure_knight.jpg" Width="100" Height="130"/>
                    <Grid>
                        <Grid.RowDefinitions>
                            <RowDefinition/>
                            <RowDefinition Height="6*"/>
                        </Grid.RowDefinitions>
                        <Label Grid.Row="0" Content="Azure Knight"  FontSize="30"/>
                        <Label Grid.Row="1" Content="Level 158"  FontSize="20"/>
                    </Grid>
                </StackPanel>
            </ComboBoxItem>
        </ComboBox>
        <Label x:Name="strLabel" Grid.Column="0" VerticalAlignment="Bottom" Height="30" Content="Str: " HorizontalContentAlignment="Center" FontSize="16"/>
        <Label x:Name="intLabel" Grid.Column="1" VerticalAlignment="Bottom" Height="30" Content="Int: " HorizontalContentAlignment="Center" FontSize="16"/>
        <Label x:Name="dexLabel" Grid.Column="0" Grid.Row="1" VerticalAlignment="Center" Height="30" Content="Dex: " HorizontalContentAlignment="Center" FontSize="16"/>
        <Label x:Name="goldLabel" Grid.Column="1" Grid.Row="1" VerticalAlignment="Center" Height="30" Content="Gold: " HorizontalContentAlignment="Center" FontSize="16"/>


    </Grid>
    <Grid Grid.Column="1">
        <Grid.RowDefinitions>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <DataGrid x:Name="MyGrid" ItemsSource="{Binding Path=Item}"></DataGrid>
    </Grid>
</Grid>

我的 XAML 是这样的，它看起来像这样:

http://puu.sh/aLLrx.png

http://puu.sh/aLLsQ.jpg

我的代码是:

 public partial class MainWindow : Window
 {

    Character aloken;
    Character azureKnight;
    Character bagiWarrior;
    Character incarMagician;
    Character segitaHunter;
    Character segnale;
    Character viciousSummoner;
    private List<Character> _charList = new List<Character>();

    public MainWindow()
    {
        InitializeComponent();
        charList.Add(new Character("Bagi Warrior"));
        this.Item = new ObservableCollection<Item>();
        this.Character = new ObservableCollection<Character>();

        this.DataContext = this;
        //Character.Add(new Character(name: "Bagi Warrior", level: 197, characterClass: CharacterClass.Bagi_Warrior, gender: Gender.Male, strength: 450, intelligence: 4, dexterity: 84, gold: 147203352));
        //Character.Add(new Character(name: "Azure Knight", level: 158, characterClass: CharacterClass.Azure_Knight, gender: Gender.Male, strength: 390, intelligence: 120, dexterity: 92, gold: 204220567));
        //Character.Add(new Character(name: "Incar Magician", level: 169, characterClass: CharacterClass.Incar_Magician, gender: Gender.Female, strength: 4, intelligence: 512, dexterity: 57, gold: 172223520));
        //Character.Add(new Character(name: "Vicious Summoner", level: 203, characterClass: CharacterClass.Vicious_Summoner, gender: Gender.Male, strength: 423, intelligence: 89, dexterity: 45, gold: 114225587));

    }

    public List<Character> charList
    {
        get { return _charList; }
        set { _charList = value; }
    }


    private ObservableCollection<Character> _Character;

    public ObservableCollection<Character> Character
    {
        get { return _Character; }
        set { _Character = value; }
    }


    private ObservableCollection<Item> _Item;
    public ObservableCollection<Item> Item
    {
        get { return _Item; }
        set { _Item = value; }
    }

}

字符类(以防万一): http://pastebin.com/GFycKqDC

元素等级(以防万一): http://pastebin.com/RgXzbFHk

这是一个 RPG 项目，您必须对组合框使用数据绑定(bind)并为组合框创建 ObservableCollection 并查看每个角色。

我遇到的问题是:在我的组合框中，我希望能够显示带有“图像”的角色以及旁边的“级别”和“名称”

但我不希望它是静态的，我想创建一个角色列表并将 ItemsSource 绑定(bind)到我的组合框，这样无论我选择哪个角色，基于该角色的信息都会更新。我该怎么做？

有人告诉我，创建一个字符列表，然后为 ComboBox Item 创建一个数据模板，其中包含绑定(bind)到 selectedItem 的图片、名称和级别就可以完成这项工作(我将其称为 charList)，但我是否这样做在代码或 XAML 中，它抛出一个异常，指出在我绑定(bind)到它之前集合必须为空。

我想将数据模板中的属性绑定(bind)到 selectedItem，以便标签和信息适当更新。

我哪里做错了，为什么会抛出这个异常？

编辑

好的，现在问题已经解决了!但是，为什么我的 Label 绑定(bind)仍然不适用于 Character.Name 和 Character.Level？

http://puu.sh/aLPr7.jpg

编辑 2 公共(public)主窗口() { 初始化组件(); Character.Add(new Character("Bagi Warrior")); Character.Add(new Character("碧蓝骑士")); this.Item = new ObservableCollection(); this.Character = new ObservableCollection();

        this.DataContext = this;
        //Character.Add(new Character(name: "Bagi Warrior", level: 197, characterClass: CharacterClass.Bagi_Warrior, gender: Gender.Male, strength: 450, intelligence: 4, dexterity: 84, gold: 147203352));
        //Character.Add(new Character(name: "Azure Knight", level: 158, characterClass: CharacterClass.Azure_Knight, gender: Gender.Male, strength: 390, intelligence: 120, dexterity: 92, gold: 204220567));
        //Character.Add(new Character(name: "Incar Magician", level: 169, characterClass: CharacterClass.Incar_Magician, gender: Gender.Female, strength: 4, intelligence: 512, dexterity: 57, gold: 172223520));
        //Character.Add(new Character(name: "Vicious Summoner", level: 203, characterClass: CharacterClass.Vicious_Summoner, gender: Gender.Male, strength: 423, intelligence: 89, dexterity: 45, gold: 114225587));

    }

    //public List<Character> charList
    //{
    //    get { return _charList; }
    //    set { _charList = value; }
    //}


    private ObservableCollection<Character> _Character;

    public ObservableCollection<Character> Character
    {
        get { return _Character; }
        set { _Character = value; }
    }

然后是 XAML:

<Grid Grid.Column="0" Background="DarkCyan">
        <Grid.ColumnDefinitions>
            <ColumnDefinition/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <ComboBox ItemsSource="{Binding Path=Character}" x:Name="comboBox" VerticalAlignment="Top" Width="Auto" Grid.ColumnSpan="2">
            <ComboBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <Image x:Name="image" Source="{Binding Source={StaticResource ImageConverter}}" Width="100" Height="150"/>
                        <Grid>
                            <Grid.RowDefinitions>
                                <RowDefinition/>
                                <RowDefinition Height="6*"/>
                            </Grid.RowDefinitions>
                            <Label Grid.Row="0" Content="{Binding Path=Character.Name}" FontSize="30"/>
                            <Label Grid.Row="1" Content="{Binding Path=Character.Level}" FontSize="20"/>
                        </Grid>
                    </StackPanel>
                </DataTemplate>
            </ComboBox.ItemTemplate>

Answer 1

您定义了 ItemsSource 两次。

一次使用

ItemsSource="{Binding charList}"

然后再用

<ComboBoxItem>

您需要将 ComboBoxItem 元素替换为 ComboBox.ItemTemplate 并为您的 ComboxItem 创建一个 DataTemplate .然后您需要将 Image Source 绑定(bind)到 Character 类的属性或使用 ItemTemplateSelector让它为项目使用适当的 DataTemplate。如果只有图像源位置发生变化，您还可以使用绑定(bind)到定义字符类的属性的数据触发器。