问题描述
尝试学习如何将对象绑定到各种类型的控件。在这种情况下,我想在我的对象中获取样本数据显示在ComboBox中。代码运行,但显示的代替值(David,Helen,Joe)是文本TheProtect.UserControls.Client)
XAML:(ucDataBindingObject.xaml) p>
< UserControl x:Class =TheProject.UserControls.ucDataBindingObject
xmlns =http://schemas.microsoft .com / winfx / 2006 / xaml / presentation
xmlns:x =http://schemas.microsoft.com/winfx/2006/xaml
xmlns:d =http:// schemas .microsoft.com / expression / blend / 2008
xmlns:mc =http://schemas.openxmlformats.org/markup-compatibility/2006
Width =Auto
高度=Auto
mc:Ignorable =d>
< Grid Width =130
Height =240
Margin =0>
< ComboBox Width =310
HorizontalAlignment =Left
VerticalAlignment =Top
ItemsSource ={Binding Path = Clients}/> ;
< / Grid>
< / UserControl>
C#:ucDataBindingObject.xaml.cs
使用系统;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Controls;
namespace TheProject.UserControls
{
public partial class ucDataBindingObject:UserControl
{
public List< Client>客户{get;组; }
public ucDataBindingObject()
{
Clients = new List< Client>();
Clients.Add(new Client(1,David)); // sample data
Clients.Add(new Client(2,Helen));
Clients.Add(new Client(3,Joe));
InitializeComponent();
this.DataContext = this;
}
}
C#Client.cs
使用System;
using System.Linq;
命名空间TheProject.UserControls
{
public class Client
{
public int ID {get;组; }
public string Name {get;组; }
public Client(int id,string name)
{
this.ID = id;
this.Name = name;
}
}
}
有几种方法告诉框架要显示什么
1)使用(这将显示命名属性):
< ComboBox ItemsSource ={Binding Path = Clients}
DisplayMemberPath =Name
/>
2)在ComboBox上设置 ItemTemplate
这就像#1,除了允许你定义一个模板显示,而不只是一个属性:
< ComboBox ItemsSource ={Binding Path = Clients}>
< ComboBox.ItemTemplate>
< DataTemplate>
< Border BorderBrush =GreenBorderThickness =1Padding =5>
< TextBlock Text ={Binding Path = Name,StringFormat ='Name:{0}'}/>
< / Border>
< / DataTemplate>
< /ComboBox.ItemTemplate>
< / ComboBox>
3)添加 ToString()
到源类。如果你总是想给一个给定的类显示相同的字符串,这是有用的。 (注意,默认的 ToString()
只是类类型名称,这就是为什么你看到TheProtect.UserControls.Client。)
public class Client
{
// ...
public override string ToString()
{
return string.Format({0}({1}),Name,ID);
}
}
4)添加到XAML资源。这对于将给定类类型与更复杂或风格化的模板相关联非常有用。
< UserControl xmlns:local =clr -namespace:TheProject.UserControls>
< UserControl.Resources>
< DataTemplate DataType =local:Client>
< TextBlock Text ={Binding Name}/>
< / DataTemplate>
< /UserControl.Resources>
// ...
< / UserControl>
Trying to learn how to bind objects to various types of controls. In this instance, I want to get sample data in my object to appear in ComboBox. The code runs but what appears instead of values (David, Helen, Joe) is text "TheProtect.UserControls.Client")
XAML: (ucDataBindingObject.xaml)
<UserControl x:Class="TheProject.UserControls.ucDataBindingObject"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
Width="Auto"
Height="Auto"
mc:Ignorable="d">
<Grid Width="130"
Height="240"
Margin="0">
<ComboBox Width="310"
HorizontalAlignment="Left"
VerticalAlignment="Top"
ItemsSource="{Binding Path=Clients}" />
</Grid>
</UserControl>
C#: ucDataBindingObject.xaml.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Controls;
namespace TheProject.UserControls
{
public partial class ucDataBindingObject : UserControl
{
public List<Client> Clients { get; set; }
public ucDataBindingObject()
{
Clients = new List<Client>();
Clients.Add(new Client(1, "David")); // sample data
Clients.Add(new Client(2, "Helen"));
Clients.Add(new Client(3, "Joe"));
InitializeComponent();
this.DataContext = this;
}
}
C# Client.cs
using System;
using System.Linq;
namespace TheProject.UserControls
{
public class Client
{
public int ID { get; set; }
public string Name { get; set; }
public Client(int id, string name)
{
this.ID = id;
this.Name = name;
}
}
}
There are several ways to tell the framework what to display
1) Use DisplayMemberPath
on the ComboBox (this will display the named property):
<ComboBox ItemsSource="{Binding Path=Clients}"
DisplayMemberPath="Name"
/>
2) Set ItemTemplate
on the ComboBox. This is like #1, except allows you to define a template to display, rather than just a property:
<ComboBox ItemsSource="{Binding Path=Clients}">
<ComboBox.ItemTemplate>
<DataTemplate>
<Border BorderBrush="Green" BorderThickness="1" Padding="5">
<TextBlock Text="{Binding Path=Name,StringFormat='Name: {0}'}" />
</Border>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
3) Add a ToString()
override to source class. Useful if you always want to display the same string for a given class. (Note that the default ToString()
is just the class type name, which is why you see "TheProtect.UserControls.Client".)
public class Client
{
// ...
public override string ToString()
{
return string.Format("{0} ({1})", Name, ID);
}
}
4) Add a DataTemplate
to the XAML resources. This is useful for associating a given class type with a more complex or stylized template.
<UserControl xmlns:local="clr-namespace:TheProject.UserControls">
<UserControl.Resources>
<DataTemplate DataType="local:Client">
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</UserControl.Resources>
// ...
</UserControl>
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