如何从其他 UserControl 访问 SimpleChildWindow

Question

我在 wpf 中有两个用户控件，并且我在它们两个中都定义了简单的子窗口现在我想以 Uc1 有 child1 和 Uc2 有 child2 的方式访问它们我想从 Uc1 访问 child2，反之亦然从代码后面。

Answer 1

我这样做的方式是通过主窗口。您不想在两个控件之间创建依赖关系。这是因为重用了用户控件。

这是一个通过事件传递孩子的示例。我不会将主窗口作为引用传递给 UserControl 的构造函数。

如果你想这样做，你应该创建一个接口并在 MainWindow 上实现它并将它作为接口传递。

喜欢：

UC1-(event)>MainWindow-(methodcall)>UC2-(methodcall)>UC2.child

---

伪代码：

// event args.
public class RequestChildEventArgs : EventArgs
{
    public Child2 Child { get;set; }
}

public class UC1
{
    // do something when you need the child2
    public void DoSomething()
    {
        var child2 = GetChild2();
        if(child2 == null)
            // cry.
    }

    // this method requests a reference of child2
    private Child2 GetChild2()
    {
        // check if the event is assigned.
        if(RequestChild == null)
            return null;

        RequestChildEventArgs args = new RequestChildEventArgs();
        RequestChild2(this, args);
        return args.Child;
    }

    public event EventHandler<RequestChildEventArgs> RequestChild2;
}

// user control 2
public class UC2
{
    public Child2 Child2 { get; } = new Child2();
}

// the mainwindow that tunnels the Child2
public class MainWindow
{
    private UC1 _uc1;
    private UC2 _uc2;

    public MainWindow()
    {
        _uc1 = new UC1();
        _uc2 = new UC2();

        _uc1.RequestChild2 += (s, e) => e.Child = _uc2.Child2;
    }
}

---

反之亦然：

伪代码：

// event args.
public class RequestChildEventArgs<T> : EventArgs
{
    public T Child { get; set; }
}

public class UC1
{
    public Child1 Child1 { get; } = new Child1();

    // do something when you need the child2
    public void DoSomething()
    {
        var child2 = GetChild2();
        if (child2 == null)
            // cry.
    }

    // this method requests a reference of child2
    private Child2 GetChild2()
    {
        // check if the event is assigned.
        if(RequestChild2 == null)
            return null;

        RequestChildEventArgs<Child2> args = new RequestChildEventArgs<Child2>();
        RequestChild2(this, args);
        return args.Child;
    }

    public event EventHandler<RequestChildEventArgs<Child2>> RequestChild2;
}

// user control 2
public class UC2
{
    public Child2 Child2 { get; } = new Child2();

    // do something when you need the child1
    public void DoSomething()
    {
        var child1 = GetChild1();
        if(child1 == null)
            // cry.
    }

    // this method requests a reference of child1
    private Child1 GetChild1()
    {
        // check if the event is assigned.
        if(RequestChild1 == null)
            return null;

        RequestChildEventArgs<Child1> args = new RequestChildEventArgs<Child1>();
        RequestChild1(this, args);
        return args.Child;
    }

    public event EventHandler<RequestChildEventArgs<Child1>> RequestChild1;
}

// the mainwindow that tunnels the Childs
public class MainWindow
{
    private UC1 _uc1;
    private UC2 _uc2;

    public MainWindow()
    {
        _uc1 = new UC1();
        _uc2 = new UC2();

        _uc1.RequestChild2 += (s, e) => e.Child = _uc2.Child2;
        _uc2.RequestChild1 += (s, e) => e.Child = _uc1.Child1;
    }
}

这样你的用户控件不依赖于主窗口或单例对象。