属性已由“FrameworkElement"注册 [英] property was already registered by 'FrameworkElement'
问题描述
我正在编写两个依赖项属性，并且在 VS11 的设计窗口中不断收到[Property] 已被 'FrameworkElement' 注册"的错误消息.这是我的代码片段
I am writing two dependency properties and I keep getting the "[Property] was already registered by 'FrameworkElement'" error in the design window of VS11. Here is a snippet of my code
public static readonly DependencyProperty IsEditingNumberProperty =
DependencyProperty.Register("IsEditingNumbers", typeof(bool), typeof(FrameworkElement),
new FrameworkPropertyMetadata(true, FrameworkPropertyMetadataOptions.AffectsRender));
问题似乎是第三个参数(所有者参数 typeof(FrameworkElement)).如果我将第三个参数设置为包含两个依赖属性的类，错误就会消失，但我不能直接从 xaml 使用这些属性.在使用之前，我必须为每个依赖属性添加所有权.
the problem seems to be the 3rd parameter (owner parameter typeof(FrameworkElement)). If I set the 3rd parameter to the class the contains two dependency properties, the error goes away, but I cannot use the properties directly from xaml. I would have to add ownership for each dependency property before I use it.
实际上，它确实呈现正确，但仅当我第一次打开它时.在第一次渲染之后，它会立即给我一个例外.在运行时，它似乎工作得很好.
Actually, It does render correctly, but only when I first open it. Immediately after the first render it will give me an exception. At runtime, it seems to work perfectly.
我做错了什么，有没有办法摆脱这个烦人的错误?
Am I doing something wrong and is there a way to get rid of this annoying error?
---- 编辑 -----
---- Edit -----
这是我的自定义类(包括 2 个依赖属性):
Here is my custom class (includes 2 of the Dependency Properties):
public partial class EditableTextBox : UserControl
{
#region Dependency Properties
public static readonly DependencyProperty IsEditingNumberProperty =
DependencyProperty.Register("IsEditingNumber", typeof(bool), typeof(FrameworkElement),
new FrameworkPropertyMetadata(true, FrameworkPropertyMetadataOptions.AffectsRender));
public static readonly DependencyProperty TextProperty =
DependencyProperty.Register("Text", typeof(string), typeof(FrameworkElement),
new FrameworkPropertyMetadata("0", FrameworkPropertyMetadataOptions.AffectsRender)
{
CoerceValueCallback = new CoerceValueCallback((sender,value) =>
{
return expressionRestaraint.Match((string)value).Value;
})
});
#endregion
public static Regex expressionRestaraint = new Regex("[-a-zA-z0-9+*.\(\)\[\]\{\}]*");
public string Text
{
get { (string)GetValue(TextProperty); }
set
{
SetValue(TextProperty, value);
tbxValue.Text = (string)GetValue(TextProperty);
}
}
public bool IsEditingNumber
{
get
{
return (bool)GetValue(IsEditingNumberProperty);
}
set
{
bool old = (bool)GetValue(IsEditingNumberProperty);
if (old != value)
{
if (!value)
stopEditing();
else
startEditing();
SetValue(IsEditingNumberProperty, value);
}
}
} . . .
在主类中使用:
<Window x:Class="VisualMathExpression.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:edit="clr-namespace:VisualMathExpression.EditableTextBox"
xmlns:all="clr-namespace:VisualMathExpression"
Title="MainWindow" Height="350" Width="525">
<StackPanel>
<edit:EditableTextBox HorizontalAlignment="Center" VerticalAlignment="Center"
Text="af" IsEditingNumber="True" /> . . .
--- 编辑---Wrapper 修复(当所有权属于声明的类时导致 xaml 属性不改变的问题)
--- Edit --- Wrapper fixed (problem that cause xaml property not to change when ownership belonged to the declared class)
public partial class EditableTextBox : UserControl
{
#region Dependency Properties
public static readonly DependencyProperty IsEditingNumberProperty =
DependencyProperty.Register("IsEditingNumber", typeof(bool), typeof(EditableTextBox),
new FrameworkPropertyMetadata(true, FrameworkPropertyMetadataOptions.AffectsRender)
{
PropertyChangedCallback = new PropertyChangedCallback((sender, arg) =>
{
EditableTextBox ed = sender as EditableTextBox;
if (!(bool)arg.NewValue)
ed.stopEditing();
else
ed.startEditing();
}),
});
public static readonly DependencyProperty TextProperty =
DependencyProperty.Register("Text", typeof(string), typeof(EditableTextBox),
new FrameworkPropertyMetadata("0", FrameworkPropertyMetadataOptions.AffectsRender)
{
PropertyChangedCallback = new PropertyChangedCallback((sender,arg) =>
{
EditableTextBox ed = sender as EditableTextBox;
ed.tbxValue.Text = arg.NewValue as string;
}),
CoerceValueCallback = new CoerceValueCallback((sender,value) =>
{
return expressionRestaraint.Match((string)value).Value;
})
});
#endregion
public static Regex expressionRestaraint = new Regex("[-a-zA-z0-9+*.\(\)\[\]\{\}]*");
public string Text
{
get { return (string)GetValue(TextProperty); }
set { SetValue(TextProperty, value); }
}
public bool IsEditingNumber
{
get { return (bool)GetValue(IsEditingNumberProperty); }
set { SetValue(IsEditingNumberProperty, value); }
}
推荐答案
DependencyProperty.Register 方法必须是声明属性的类.
The third parameter ownerType of the DependencyProperty.Register method must be the class that declares the property.
如果您的类是 MyClass，则声明必须如下所示:
If your class is MyClass the declaration would have to look like this:
public class MyClass : DependencyObject
{
public static readonly DependencyProperty IsEditingNumberProperty =
DependencyProperty.Register(
"IsEditingNumber", typeof(bool), typeof(MyClass), ...);
// CLR wrapper
public bool IsEditingNumber
{
get { return (bool)GetValue(IsEditingNumberProperty); }
set { SetValue(IsEditingNumberProperty, value); }
}
}
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