[英]wpf fire PropertyChanged event in binding source that binding gets updated
I'm trying to make some CustomControl Textboxes with validation features. 我正在尝试制作一些具有验证功能的CustomControl文本框。 (for example a number only textbox or a zip-code textbox etc.) It should realized in a .dll library file.
(例如,仅数字文本框或邮政编码文本框等。)应在.dll库文件中实现。
My project contains a CustomControl for the textbox, a class wich handles the validations, and a ErrMsgGui CustomControl that should show a error message in a TextBlock (exmp.: Only numbers allowed...) 我的项目包含一个用于文本框的CustomControl,一个用于处理验证的类以及一个ErrMsgGui CustomControl,该控件应在TextBlock中显示错误消息(示例:仅允许数字...)
My problem is that I don't get the TextBlock Text updated when a method in the validation class is called 我的问题是,当调用验证类中的方法时,我没有更新TextBlock Text
Is there a way to trigger the PropertyChangeEvent which updates the Textblock text within the validaiton class? 有没有一种方法可以触发PropertyChangeEvent来更新validaiton类中的Textblock文本?
(Im quite new to wpf) (对wpf来说还很陌生)
Generic.xaml: Generic.xaml:
<Style TargetType="{x:Type local:NumTb}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:NumTb}">
<TextBox Background="{TemplateBinding Background}" Text="{Binding Source={StaticResource NumTbVm}, Path=NumTbText, UpdateSourceTrigger=PropertyChanged}"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style TargetType="{x:Type local:ErrMsgGui}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:ErrMsgGui}">
<TextBlock Text="{ Binding Source={StaticResource val}, Path=ErrMsgGuiText, UpdateSourceTrigger=PropertyChanged}" Background="{TemplateBinding Background}"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Validations.cs: Validations.cs:
private const string ONLY_NUMBERS_REGEX = @"^[0-9]+$"; //Nur Zahlen
private string _ErrMsgGuiText;
public string ErrMsgGuiText
{
get { return _ErrMsgGuiText; }
set
{
_ErrMsgGuiText = value;
Debug.Print("QueryText: " + value);
OnPropertyChanged("ErrMsgGuiText");
}
}
public object[] onlyNumbers(string s2c, bool output)
{
object[] objRes = new object[2];
bool result = true;
string errMsg = "";
Regex regex = new Regex(ONLY_NUMBERS_REGEX);
if (s2c != null && s2c != "" && !regex.IsMatch(s2c))
{
result = false;
errMsg = "Nur Zahlen sind zulässig";
}
objRes[0] = result;
objRes[1] = errMsg;
if (output == true)
{
ErrMsgGuiText = errMsg;
}
return objRes;
}
public void onlyNumbers(string s2c)
{
onlyNumbers(s2c, true);
}
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
#endregion
protected void OnPropertyChanged(string prop)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(prop));
}
}
NumTbViewModel.cs: NumTbViewModel.cs:
Validations val = null;
public NumTbViewModel()
{
val = new Validations();
}
private string _NumTbText;
public string NumTbText
{
get { return _NumTbText; }
set
{
_NumTbText = value;
this.OnPropertyChanged("NumTbText");
val.onlyNumbers(_NumTbText);
}
}
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
#endregion
protected void OnPropertyChanged(string prop)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(prop));
}
}
It looks like the TextBlock source is looking at a static resource for the Validations class and the Validations called in your NumTbViewModel is NOT the same as the static resource. 看来TextBlock源正在为Validations类寻找静态资源,并且您的NumTbViewModel中调用的Validations与静态资源不同。 A solution could be to add a property to NumTbViewModel.cs and point your binding to that property so the Validations class instances will be the same.
一种解决方案是向NumTbViewModel.cs添加一个属性,然后将您的绑定指向该属性,以便Validations类实例相同。 In NumTbViewModel.cs add:
在NumTbViewModel.cs中添加:
Validations _val;
public Validations Val
{
get { return _val; }
set
{
_val = value;
this.OnPropertyChanged("Val");
}
}
Change your source and path in xaml binding on the TextBlock: 在TextBlock上的xaml绑定中更改源和路径:
<TextBlock Text="{ Binding Source={StaticResource NumTbVm}, Path=Val.ErrMsgGuiText, UpdateSourceTrigger=PropertyChanged}" Background="{TemplateBinding Background}"/>
Another way: You could also set the Val property of your NumTbViewModel when you define your static resource like so: 另一种方法:在定义静态资源时,还可以设置NumTbViewModel的Val属性,如下所示:
<local:Validations x:Key="val" />
<local:NumTbViewModel x:Key="NumTbVm" Val="{StaticResource val}" />
Doing this you can keep the bindings like you originally had. 这样做可以使绑定保持原来的样子。
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