如何设置ListView的ItemsSource? [英] How to set ItemsSource of ListView?

问题描述

这里我定义了我的数据myListOfEmployeeObjects:

Here I have defined my data myListOfEmployeeObjects:

public class App : Application
{
    public List<Employee> myListOfEmployeeObjects;

    public App ()
    {
        Employee emp1 = new Employee () {
            FirstName = "Max",
            LastName = "Mustermann",
            Twitter = "@fake1"
        };
        Employee emp2 = new Employee () {
            FirstName = "Evy",
            LastName = "Mustermann",
            Twitter = "@fake2"
        };
        myListOfEmployeeObjects = new List<Employee> {
            emp1, emp2
        };
        MainPage = new NavigationPage (new EmployeeListPage ());
    }
}

比我在 XAML 中设置 ItemsSource 的地方:

Than I have my XAML where I set the ItemsSource:

<ListView x:Name="listView"
                IsVisible="false"
                ItemsSource="{x:Static local:App.myListOfEmployeeObjects}"
                ItemSelected="EmployeeListOnItemSelected">

这应该有效吗?因为我得到

Should this work? Because I get

Xamarin.Forms.Xaml.XamlParseException:在 xmlns 中找不到类型应用

Xamarin.Forms.Xaml.XamlParseException: Type App not found in xmlns

public partial class EmployeeListPage : ContentPage {

    private ListView listView;

    private void InitializeComponent() {
        this.LoadFromXaml(typeof(EmployeeListPage)); // here the exception is thrown
        listView = this.FindByName <ListView>("listView");
    }
}

如何设置 XAML 的 ItemsSource?

How can I set the ItemsSource of my XAML?

现在我尝试了来自 user2425632 的建议，如果我进行以下更改，它会起作用:

Now I tried the suggestion from user2425632 and it works if I do the following changes:

1. 将 xmlns:local="clr-namespace:HelloXamarinFormsWorld;assembly=HelloXamarinFormsWorld" 添加到我的 XAML 文件

1. Adding xmlns:local="clr-namespace:HelloXamarinFormsWorld;assembly=HelloXamarinFormsWorld" to my XAML file

现在看起来像下图

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:HelloXamarinFormsWorld;assembly=HelloXamarinFormsWorld"
             x:Class="HelloXamarinFormsWorld.EmployeeListPage"
             Title="Employee List">
    <ContentPage.Content>

当然，您必须更改名称以适合您的项目.

Of course you have to change the names so that it suits to your project.

1. 显示列表视图

我删除了 IsVisible 和 ItemSelected.

<ListView ItemsSource="{x:Static local:App.myListOfEmployeeObjects}">

1. 让一切保持静态

它必须是静态的，否则你会得到

It has to be static, otherwise you get

未找到 local:App.myListOfEmployeeObjects 的静态成员

No static member found for local:App.myListOfEmployeeObjects

public static List<Employee> myListOfEmployeeObjects { private set; get; }

public static void GetAllEmployees(){
    Employee emp1 = new Employee () {
        FirstName = "Max",
        LastName = "Mustermann",
        Twitter = "@fake1"
    };
    Employee emp2 = new Employee () {
        FirstName = "Eva",
        LastName = "Mustermann",
        Twitter = "@fake2"
    };
    myListOfEmployeeObjects = new List<Employee> {
        emp1, emp2
    };
}

public App ()
{
    GetAllEmployees ();
    MainPage = new NavigationPage (new EmployeeListPage ());
}

推荐答案

所以我自己实际上还没有开始做这件事，但是通过阅读文档我有一个建议，可能值得你尝试.

So I haven't actually gotten around to doing this myself but from reading the documentation I have a suggestion which may be worth you trying.

ItemsSource="{x:Static local:App.myListOfEmployeeObjects}"

在您的 xaml 中，您已经说过源代码是静态的，但查看您的 .cs 文件却不是.请尝试以下操作:

In your xaml you've said that the source is static but looking at your .cs file it isn't. Try the following:

public static List<Employee> myListOfEmployeeObjects { private set; get; }

然后尝试使用静态函数设置对象，例如:

and then try and set the object using a static function, eg.:

static App() {
    myListOfEmployeeObjects = something;
}

然后列表应该可以在页面上查看.

Then the list should be viewable on the page.

我使用了您可能会觉得有用的以下链接:

I used the following links which you may find useful:

关于数据的 Xamarin 文档-绑定

示例 cs 代码

示例 xaml 代码

希望有所帮助.

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