获取父用户控件的属性值，从孩子的用户控件 [英] Getting value of a property in Parent User control from a Child user control

问题描述

我有一个是一个ParentUserControl内加载的ChildUserControl。主机页面加载ParentUserControl。

I have a ChildUserControl that is loaded inside a ParentUserControl. The host page loads ParentUserControl.

我需要从ChildUserControl访问ParentUserControl属性。

I would need to access properties in ParentUserControl from the ChildUserControl.

感谢您的时间

推荐答案

该平台/语言等不明确，所以这个答案必然是模糊的......不过，一般子控件不能从访问属性母公司（直接），因为很多不同类型的家长控制，可以承载子控件。孩子不应该是硬coded到一个单亲家庭，否则很可能会成为部分母公司。

The platform / language etc isn't clear, so this answer is necessarily vague... however, in general a child control can't access properties from the parent (directly), because lots of different types of parent controls could be hosting the child control. The child shouldn't be hard-coded to a single parent, otherwise it might as well be part of the parent.

通常情况下，你可能想尝试简单地删除的要求 - 这听起来像一个奇怪的设计。然而，一些框架，支持东西的喜欢的这 - 例如，在WPF依赖属性

Generally, you might want to try to simply remove the requirement - it sounds like an odd design. However, some frameworks support something like this - for example, dependency properties in WPF.

这是基于接口的设计（父（多个））是一种方法，但是这不是很干净。对于.NET，事件等都是对孩子与父母沟通另一种常见的方式 - 孩子暴露出其不同的家长可以以不同的方式消耗事件

An interface-based design (for the parent(s)) is one approach, but this isn't very clean. For .NET, events etc are another common way for a child to communicate with a parent - the child exposes events which different parents can consume in different ways.

除此之外，你进入测试区域/压铸父（无论是对一个类或接口），从父访问的细节 - 例如：

Other than that, you're into the territory of testing/casting the parent (either against a class or an interface) to access details from the parent - for example:

ParentControlType parent = this.Parent as ParentControlType;
if(parent != null) {
    // access properties etc of "parent"
}

（也可以在这里使用的接口;还是有点哈克无论哪种方式...）

(could also use an interface here; still a bit hacky either way...)

个人，而不是使用这种类型的投自孩子，我想preFER父采取控制;父的子集的属性，并监听事件（而不是子集的属性回父）：

Personally, rather than use this type of cast from the child, I'd prefer the parent to take control; the parent sets properties on the child, and listens to events (rather than the child set properties back on the parent):

// in the parent
child.SomeProperty = 132;
child.SomePropertyChangd += delegate {
    // do something at the parent
};

这样一来，孩子不知道或关心父母。所有它知道的是，它具有性质（等），并可以通知其他人有趣的变化。

This way, the child doesn't know or care about the parent. All it knows is that it has properties (etc), and can notify other people to interesting changes.

这篇关于获取父用户控件的属性值，从孩子的用户控件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！