WPF绑定一个TextBlock到App物业的成员 [英] Wpf Binding a TextBlock to App Property's member

问题描述

在我的WPF应用程序，我想一个对象CaseDetails予以即通过所有窗口和放大器全球范围内使用;用户控件。 CaseDetails实现INotifyPropertyChanged，并有一个属性CaseName。

In my WPF app, I want an object "CaseDetails" to be used globally i.e. by all windows & user controls. CaseDetails implements INotifyPropertyChanged, and has a property CaseName.

public class CaseDetails : INotifyPropertyChanged
{
    private string caseName, path, outputPath, inputPath;

    public CaseDetails()
    {
    }

    public string CaseName
    {
        get { return caseName; }
        set
        {
            if (caseName != value)
            {
                caseName = value;
                SetPaths();
                OnPropertyChanged("CaseName");
            }
        }
    }
    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(propertyName));
    }

    public event PropertyChangedEventHandler PropertyChanged;

在我App.xaml.cs，我创建CaseDetails的对象

In my App.xaml.cs, I created an object of CaseDetails

public partial class App : Application
{
    private CaseDetails caseDetails;

    public CaseDetails CaseDetails
    {
        get { return this.caseDetails; }
        set { this.caseDetails = value; }
    }

在我的用户控制code后面的一个，我创建CaseDetails的对象，并在App类设置

In one of my user control code behind, I create object of CaseDetails and set in App class

(Application.Current as App).CaseDetails = caseDetails;

和App类的CaseDetails对象被更新。

And the CaseDetails object of App class is updated.

在我MainWindow.xml，我有一个绑定到CaseName CaseDetails财产一个TextBlock。这个文本块不会更新。该XML code是：

In my MainWindow.xml, I have a TextBlock that is bind to CaseName property of CaseDetails. This Textblock doesn't update. The xml code is :

<TextBlock Name="caseNameTxt" Margin="0, 50, 0, 0" FontWeight="Black" TextAlignment="Left" Width="170" Text="{Binding Path=CaseDetails.CaseName, Source={x:Static Application.Current} }"/>

为什么这样的TextBlock文本poperty是没有得到更新？我要去哪里错了??绑定

Why this TextBlock Text poperty is not getting updated ?? Where am I going wrong in Binding ??

推荐答案

绑定没有更新，因为你在你的App类，它不设置 CaseDetails 属性不实现INotifyPropertyChanged。

The binding isn't updated because you are setting the CaseDetails property in your App class, which does not implement INotifyPropertyChanged.

要么你也实现INotifyPropertyChanged在你的应用程序类，或者你刚刚设置的现有CaseDetails实例的属性：

Either you also implement INotifyPropertyChanged in your App class, or you just set properties of the existing CaseDetails instance:

(Application.Current as App).CaseDetails.CaseName = caseDetails.CaseName;
...

的 CaseDetails 属性可能再是只读的：

The CaseDetails property might then be readonly:

public partial class App : Application
{
    private readonly CaseDetails caseDetails = new CaseDetails();

    public CaseDetails CaseDetails
    {
        get { return caseDetails; }
    }
}

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