[英]How can I have the respective object in a CollectionView?
我正在尝试使用使用CollectionView
的动态创建的布局来显示 class 的一系列属性,所有属性都基于列表,我想使其中一个属性是Combobox
。 我怎么知道 object 和ComboBox
需要引用什么?
这是我的CollectionView
:
<CollectionView x:Name="taskList">
<CollectionView.ItemTemplate>
<DataTemplate x:DataType="models:Task">
<VerticalStackLayout Margin="15">
<Entry Text="{Binding name}" IsReadOnly="True" />
<Entry Text="{Binding departmentsString}" IsReadOnly="True"/>
<HorizontalStackLayout>
<inputs:SfComboBox BackgroundColor="Black" TextColor="Green" DropDownIconColor="Green"/>
<Entry Text="{Binding deadline}" IsReadOnly="True" />
<Entry Text="{Binding author.fullName}" IsReadOnly="True"/>
</HorizontalStackLayout>
<Entry Text="{Binding description}" IsReadOnly="True" />
</VerticalStackLayout>
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
它的 ItemsSource 声明如下:
taskList.ItemsSource = tasks;
任务是:
ObservableCollection<Classes.Task> tasks { get; set; }
这是任务 class:
public class Task
{
public Task(string name, List<string> departments, Status status, DateOnly deadline, Employee author, string description)
{
this.name = name;
this.departments = departments;
this.status = status;
this.deadline = deadline;
this.author = author;
this.description = description;
}
public string name { get; private set; }
public List<string> departments { get; private set; } = new List<string>();
public string departmentsString
{
get
{
string _ = "";
foreach (var department in departments)
{
_ += department + (department == departments.Last() ? "": ", ");
}
return _;
}
}
public Status status { get; private set; }
public DateOnly deadline { get; private set; }
public Employee? author { get; set; }
public string description { get; private set; }
public List<Employee> employees { get; private set; } = new List<Employee>();
public void AddEmployee(Employee employee)
{
if (departments.Contains(employee.department))
{
employees.Add(employee);
}
}
}
我该怎么做才能根据更改的ComboBox
确定 class Task
的实例?
这是用户界面的样子:
尝试将 combobox 绑定到 Status 属性
您可以尝试为SfComboBox
的属性ItemsSource
设置数据列表,并将字段绑定到SfComboBox
的属性SelectedItem
。
假设您将departments
绑定到SfComboBox
的ItemsSource
,那么我们需要添加一个字段(例如SelectedItem
)绑定到SfComboBox
的属性SelectedItem
:
然后我们需要为MyTask.cs
实现接口INotifyPropertyChanged
并添加字段SelectedItem
。(为了防止与我项目中的Task
class 冲突,我将其命名为MyTask
)
//add SelectedItem here
private string _selectedItem;
public string SelectedItem
{
get => _selectedItem;
set => SetProperty(ref _selectedItem, value);
}
MyTask
的全部代码
public class MyTask: INotifyPropertyChanged
{
public MyTask(string name, List<string> departments, int status, DateTime deadline, Employee author, string description)
{
this.name = name;
this.departments = departments;
this.status = status;
this.deadline = deadline;
this.author = author;
this.description = description;
}
//add SelectedItem here
private string _selectedItem;
public string SelectedItem
{
get => _selectedItem;
set => SetProperty(ref _selectedItem, value);
}
bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = null)
{
if (Object.Equals(storage, value))
return false;
storage = value;
OnPropertyChanged(propertyName);
return true;
}
protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
public event PropertyChangedEventHandler PropertyChanged;
public string name { get; set; }
public List<string> departments { get; private set; } = new List<string>();
public string departmentsString
{
get
{
string _ = "";
foreach (var department in departments)
{
_ += department + (department == departments.Last() ? "" : ", ");
}
return _;
}
}
public int status { get; private set; }
public DateTime deadline { get; private set; }
public Employee? author { get; set; }
public string description { get; private set; }
public List<Employee> employees { get; private set; } = new List<Employee>();
public void AddEmployee(Employee employee)
{
if (departments.Contains(employee.department))
{
employees.Add(employee);
}
}
}
然后我们可以这样使用:
<editors:SfComboBox BackgroundColor="Black" TextColor="Green"
DropDownIconColor="Green"
WidthRequest="250"
ItemsSource="{Binding departments}"
SelectedItem="{Binding SelectedItem}"
/>
笔记:
然后如果我们更改SfComboBox
的选项, SelectedItem
的值也会自动更新。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.