如何在Xamarin Forms MasterDetailPage项目中一次加载detailpage

本文介绍了如何在Xamarin Forms MasterDetailPage项目中一次加载detailpage的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我注意到每次选择主页页面菜单项时都会从头开始加载detailpage(因此每次都调用它的构造函数). 有没有一种方法可以实现一次加载一次的详细信息页面，因此每次选择菜单项时，都会简单地显示/不显示详细信息页面?

I noticed detailpage is loaded from scratch everytime masterpage menu item is selected (so its constructor is called everytime). Is there a way to implement a detailpage which is loaded once, so everytime menu item is selected detailpage is simply showed/not showed?

谢谢， 刘易斯

推荐答案

我解决了在MasterDetailPage中实现字典页面缓存的问题:

I solved implementing a dictionary page cache in MasterDetailPage:

// in constructor MasterPageMenuCache = new Dictionary<Type, Page>(); // in OnItemSelected if (MasterPageMenuCache.Count == 0) MasterPageMenuCache.Add(typeof(FirstDefaultDetailPage), Detail); var item = e.SelectedItem as MasterPageItem; if (item != null) { if (MasterPageMenuCache.ContainsKey(item.TargetType)) { Detail = MasterPageMenuCache[item.TargetType]; } else { Detail = new NavigationPage((Page)Activator.CreateInstance(item.TargetType)); MasterPageMenuCache.Add(item.TargetType, Detail); } masterPage.ListView.SelectedItem = null; IsPresented = false; }