尝试编辑类型化DataTemplate时出现奇怪的绑定错误 [英] Weird binding error while trying to edit typed DataTemplate
问题描述
我有一个ViewModel（TestViewModel），它有一个只读的 """"属性。在这个ViewModel中，我有一个名为Model（TestModel）的属性，它也有一个"Name"。属性不是只读的。然后我定义一个DataTemplate为TestViewModel到的它的模型属性
显示名称和说明字段
现在，当我从"打开MainWindow.xaml;表达混合"并从资源选项卡尝试编辑此DataTemplate我收到以下错误：
" TwoWay或OneWayToSource绑定无法在'DataTemplateError类型的只读属性'Name'上工作。 TestViewModel'。"
DataTemplate在项目运行时按预期工作;所以绑定是正确的。但是当尝试通过Blend编辑/设计DataTemplate时，它无法正常工作。虽然我将StackPanel的DataContext设置为Model，但它给出的错误就像TextBox
for """"属性 结合至 仅"读;姓名"  TestViewModel的属性：
我提供以下必要的代码的文件和我使用表达混合4 SP1
提前致谢
--------------------------- -------------------------------------------------- -------------------------------------------------- ---------------------------------------------
TestModel类如下：
使用 System;
使用 System.ComponentModel;
命名空间 DataTemplateError {
public class < span style ="color：＃2b91af"> TestModel ： INotifyPropertyChanged {
; privatestring _Name = " Runtime Model Name" ;
;&NBSP;&NBSP;&NBSP;的私有&NBSP;的串&NBSP; _Description&NBSP; =&NBSP;的"运行时 型号 描述" ;
public string 名称 {
get { return 此 ._名称; }
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;的设置&NBSP; {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ; _Name = value ;
this .NotifyPropertyChanged（"姓名" ）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;}
&NBSP;&NBSP;&NBSP;&NBSP;}
public string 说明 {
get { return 此 ._说明; }
设置 {
_Description = value ;
this .NotifyPropertyChanged（" Description" ; ）; }
}
; public event &n bsp; PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged（ String info） {
if （PropertyChanged ！= null ） {
PropertyChanged（ this ， new PropertyChangedEventArgs （info））;
} }
}
}
TestViewModel类如下：
使用 系统;
使用 System.ComponentModel;
< span style ="color：blue">命名空间 DataTemplateError {
public class TestViewModel ： INotifyPropertyChanged {
private string _Name = " Runtime ViewModel Name" ;
public string 名称 {
; get { return 这个 ._名称; }
private 设置&NBSP; {
&NBSP;&NBSP;&NBSP;&NBSP ; _Name = value ;
此 .NotifyPropertyChanged（" Name" ）;
; } }
private TestModel _Model = new TestModel （）;
public TestModel 型号 {
get { ; 返回 此 ._型号; }
; 设置 {
&n bsp; _Model = value ;
此 .NotifyPropertyChanged（" Model" ）;
} }
public < span style ="color：blue"> void UpdateNameMethod（） {
if （！ this .Name.EndsWith（" Updated Value" ， ; StringComparison .Ordinal）） {
Name = Name ; + " - 已更新 值" ; }
}
&n bsp; public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged（ String info） {
if （PropertyChanged ！= null ） {
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;的PropertyChanged（的此，&NBSP;的新&NBSP; <跨度风格= "颜色：＃2b91af"> PropertyChangedEventArgs （信息））;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;}
&NBSP;&NBSP;&NBSP;&NBSP;} <无线电通信/> }
}
看起来好像是因为它实际上是针对您的Test上的Name属性ViewModel类，具有私有集方法：
public string Name {
get {return this._Name; }
private set {
_Name = value;
this.NotifyPropertyChanged（" Name"）;
}
}
Hi,
I have a ViewModel (TestViewModel) which has a read only "Name" property. In this ViewModel I have property named Model(TestModel) which also has a "Name" property which is NOT read only. Then I defined a DataTemplate for TestViewModel to show Name and Description fields of it's Model property.
Now when I open MainWindow.xaml from "Expression Blend" and from the resources tab try to edit this DataTemplate I get the following error:
"A TwoWay or OneWayToSource binding cannot work on the read-only property 'Name' of type 'DataTemplateError.TestViewModel'."
The DataTemplate works as expected when the project runs; so the bindings are correct. But when trying to edit/design DataTemplate through Blend it's not working. Although I set the DataContext of StackPanel to Model it's giving the error as if the TextBox for "Name" property is bound to read only "Name" property of TestViewModel:
I've supplied the necessary code files below and I'm using Expression Blend 4 SP1.
Thanks in advance
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TestModel class is below:
using System;
using System.ComponentModel;
namespace DataTemplateError {
public class TestModel : INotifyPropertyChanged {
private string _Name = "Runtime Model Name";
private string _Description = "Runtime Model Description";
public string Name {
get { return this._Name; }
set {
_Name = value;
this.NotifyPropertyChanged("Name");
}
}
public string Description {
get { return this._Description; }
set {
_Description = value;
this.NotifyPropertyChanged("Description");
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String info) {
if (PropertyChanged != null) {
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}
}
}
TestViewModel class is below:
using System;
using System.ComponentModel;
namespace DataTemplateError {
public class TestViewModel : INotifyPropertyChanged {
private string _Name = "Runtime ViewModel Name";
public string Name {
get { return this._Name; }
private set {
_Name = value;
this.NotifyPropertyChanged("Name");
}
}
private TestModel _Model = new TestModel();
public TestModel Model {
get { return this._Model; }
set {
_Model = value;
this.NotifyPropertyChanged("Model");
}
}
public void UpdateNameMethod() {
if (!this.Name.EndsWith("Updated Value", StringComparison.Ordinal)) {
Name = Name + " - Updated Value";
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String info) {
if (PropertyChanged != null) {
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}
}
}
It looks like it is because it is actually targeting the Name property on your TestViewModel class, which has a private set method:
public string Name { get { return this._Name; } private set { _Name = value; this.NotifyPropertyChanged("Name"); } }
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