无法循环遍历wpf treeview parent及其子节点...我获取父节点值但其子节点返回null值。

本文介绍了无法循环遍历wpf treeview parent及其子节点...我获取父节点值但其子节点返回null值。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 29岁程序员，3月因学历无情被辞！ 无法循环遍历wpf treeview parent及其子节点...我得到父节点值但其子节点返回空值。 下面是我的WPF树视图和#code如何绑定。我使用DataContext绑定数据，这是正常的。 我想隐藏/显示ImgLogin图像，以便从代码后面动态显示。 < treeview margin = 368 ，61,0,0 itemssource = {Binding} x：名称 = tvGroupUsers horizo​​ntalalignment = 左 verticalalignment = 顶部 width = 245 height = 375 rendertransformorigin = -4.929,1.701 grid.column = 1 xmlns： x = ＃unknown > < treeview.resources > < datatemplate x：key = childrenDataTemplate > < stackpanel orientation = 水平 > < border 名称 = CornersMask 已删除 = SkyBlue cornerradius = 50 height = 30 width = 30 horizo​​ntalalignment = 左 margin = - 25,5,5,5 verticalalignment = Top / > < 图像 名称 = image1 Source = {Binding DisplayedImage} 拉伸 = 填充 UseLayoutRounding = True 高度 = 30 宽度 = 30 Horizo​​ntalAlignment = 左 保证金 = -34,4,0,0 VerticalAlignment = Top > < Image.OpacityMask > < visualbrush visual = {Binding ElementName = CornersMask} / > < /Image.OpacityMask> < Image.Effect > < dropshadoweffect / > < / Image.Effect > < / Image > < 标签 内容 = {Binding Path = Name} > < / Label > < 图像 名称 = ImgAlert 可见性 = 可见 高度 = 16 宽度 = 16 标签 = {Binding Path = UserID} 来源 = {Binding ImgAlertMsg} > < / Image > < 图像 名称 = ImgLogin 可见性 = 可见 高度 = 15 宽度 = 16 标记 = {Binding Path = UserID} 来源 = {Binding ImgLogin} > < / Image > < 标签 内容 = {Binding Path = UserID} 可见性 = 隐藏 / > < / stackpanel > < / datatemplate > < / treeview.resources > < treeview.itemtemplate > < hierarchicaldatatemplate itemssource = {Binding Path = ClientsList} itemtemplate = {StaticResource ResourceK ey = childrenDataTemplate} > < textblock text = {Binding Path = ChatGroup} fontweight = 粗体 / > < / hierarchicaldatatemplate > < / treeview.itemtemplate > < / treeview > 以下是代码背后的代码.. lstGroups = proxy.GetExistingGroups（）; if （lstGroups.Count > 0 ） { for （ int i = 0 ; i < lstGroups.Count; i ++） { SVC.Groups objGroups = new SVC.Groups（）; objGroups.GroupID = lstGroups [i] .GroupID; objGroups.ChatGroup = objUtilities.ConvertToCamelCase（lstGroups [i] .ChatGroup）; if （objGroups.GroupID == 0 ） { lstClient = proxy.GetUsers（ this .localClient.UserID.ToString（））; finallstClient = new 列表< SVC.Client>（）; for （ int k = 0 ; k < lstClient.Count; k ++） { objUtilities = new Utilities（）; SVC.Client objClient = new SVC.Client（）; objClient.DisplayedImage = ; objClient.FirstName = lstClient [k] .FirstName; objClient.LastName = lstClient [k] .LastName; objClient.UserID = lstClient [k] .UserID; objClient.PersonalMail = lstClient [k] .PersonalMail; objClient.Name = lstClient [k] .FirstName + + lstClient [k] 。姓; objClient.Picture = lstClient [k] .Picture; objClient.ImgAlertMsg = ImgAlertMsg; objClient.ImgLogin = ImgLogin; if （lstClient [k] .Picture！= null ） { objClient.DisplayedImage = CreateUserImages（objClient）; } else { objClient.DisplayedImage = defaultPath; } finallstClient.Add（objClient）; AllClients.Add（lstClient [k] .UserID.ToString（），objClient）; } objGroups.ClientsList = finallstClient; } else { lstClient = proxy.GetGroupUsers（objGroups.GroupID.ToString（），此 .localClient.UserID.ToString（））; if （lstClient.Count > 0 ） { finallstClient = new 列表< SVC.Client>（）; for （ int j = 0 ; j < lstClient.Count; j ++） { objUtilities = new Utilities（）; SVC.Client objClient = new SVC.Client（）; objClient.DisplayedImage = ; objClient.FirstName = lstClient [j] .FirstName; objClient.LastName = lstClient [j] .LastName; objClient.UserID = lstClient [j] .UserID; objClient.PersonalMail = lstClient [j] .PersonalMail; objClient.Name = lstClient [j] .FirstName + + lstClient [j] 。姓; objClient.Picture = lstClient [j] .Picture; objClient.ImgAlertMsg = ImgAlertMsg; objClient.ImgLogin = ImgLogin; if （lstClient [j] .Picture！= null ） { objClient.DisplayedImage = CreateUserImages（objClient）; } else { objClient.DisplayedImage = defaultPath; } finallstClient.Add（objClient）; } objGroups.ClientsList = finallstClient; } } finallstGroups.Add（objGroups）; } tvGroupUsers.DataContext = finallstGroups; 紧急请尽快回复... 在此先感谢.. 我尝试过： foreach （ object parent in items.Items） { TreeViewItem treeItem = this .tvGroupUsers.ItemContainerGenerator.ContainerFromItem（parent） as TreeViewItem; ItemsControl childControl = ItemsControl.ItemsControlFromItemContainer（treeItem）; foreach （ object child in treeItem.Items） { TreeViewItem childtreeview = this .tvGroupUsers.ItemContainerGenerator.ContainerFromItem（child） as TreeViewItem; } } childtreeview return null 解决方案 在代码背后使用此Helper方法 T GetVisualChild< t>（DependencyObject parent， string name）其中 T：Visual { T child = 默认（T）; int numVisuals = VisualTreeHelper.GetChildrenCount（parent）; for （ int i = 0 ; i < numVisuals; i ++） { Visual v =（Visual）VisualTreeHelper.GetChild（parent，i）; child = v as T; if （child == null ） { child = GetVisualChild< t>（v，name）; } if （child！= null ） { break ; } } return child; } < / t > < / t > 您只需要 例如。在您的代码中首先声明您的图像 图像ImgAlert = new 图像（）; 你的构造函数或加载方法 然后你的活动你可以这个叫方法by ImgAlert = GetVisualChild< treeview>（ this ， ImgAlert）; < / treeview > Cannot looping through wpf treeview parent and its child node ...I get Parent node value but its child return null value.Below is my WPF treeview and #code how it is binding . I am using DataContext to bind data , which is working fine .I want to hide / show the ImgLogin image to dynamically from code behind.<treeview margin="368,61,0,0" itemssource="{Binding}" x:name="tvGroupUsers" horizontalalignment="Left" verticalalignment="Top" width="245" height="375" rendertransformorigin="-4.929,1.701" grid.column="1" xmlns:x="#unknown"> <treeview.resources> <datatemplate x:key="childrenDataTemplate"> <stackpanel orientation="Horizontal"> <border name="CornersMask" removed="SkyBlue" cornerradius="50" height="30" width="30" horizontalalignment="Left" margin="-25,5,5,5" verticalalignment="Top" /> <Image Name="image1" Source="{Binding DisplayedImage}" Stretch="Fill" UseLayoutRounding="True" Height="30" Width="30" HorizontalAlignment="Left" Margin="-34,4,0,0" VerticalAlignment="Top"> <Image.OpacityMask> <visualbrush visual="{Binding ElementName=CornersMask}" /> </Image.OpacityMask> <Image.Effect> <dropshadoweffect /> </Image.Effect> </Image> <Label Content="{Binding Path=Name}"></Label> <Image Name="ImgAlert" Visibility="Visible" Height="16" Width="16" Tag="{Binding Path=UserID}" Source="{Binding ImgAlertMsg}"></Image> <Image Name="ImgLogin" Visibility="Visible" Height="15" Width="16" Tag="{Binding Path=UserID}" Source="{Binding ImgLogin}"></Image> <Label Content="{Binding Path=UserID}" Visibility="Hidden"/> </stackpanel> </datatemplate> </treeview.resources> <treeview.itemtemplate> <hierarchicaldatatemplate itemssource="{Binding Path=ClientsList}" itemtemplate="{StaticResource ResourceKey=childrenDataTemplate}"> <textblock text="{Binding Path=ChatGroup}" fontweight="Bold" /> </hierarchicaldatatemplate> </treeview.itemtemplate> </treeview>Below is my Code behind code ..lstGroups = proxy.GetExistingGroups(); if (lstGroups.Count > 0) { for (int i = 0; i < lstGroups.Count; i++) { SVC.Groups objGroups = new SVC.Groups(); objGroups.GroupID = lstGroups[i].GroupID; objGroups.ChatGroup = objUtilities.ConvertToCamelCase(lstGroups[i].ChatGroup); if (objGroups.GroupID == 0) { lstClient = proxy.GetUsers(this.localClient.UserID.ToString()); finallstClient = new List<SVC.Client>(); for (int k = 0; k < lstClient.Count; k++) { objUtilities = new Utilities(); SVC.Client objClient = new SVC.Client(); objClient.DisplayedImage = ""; objClient.FirstName = lstClient[k].FirstName; objClient.LastName = lstClient[k].LastName; objClient.UserID = lstClient[k].UserID; objClient.PersonalMail = lstClient[k].PersonalMail; objClient.Name = lstClient[k].FirstName + " " + lstClient[k].LastName; objClient.Picture = lstClient[k].Picture; objClient.ImgAlertMsg = ImgAlertMsg; objClient.ImgLogin = ImgLogin; if (lstClient[k].Picture != null) { objClient.DisplayedImage = CreateUserImages(objClient); } else { objClient.DisplayedImage = defaultPath; } finallstClient.Add(objClient); AllClients.Add(lstClient[k].UserID.ToString(), objClient); } objGroups.ClientsList = finallstClient; } else { lstClient = proxy.GetGroupUsers(objGroups.GroupID.ToString(), this.localClient.UserID.ToString()); if (lstClient.Count > 0) { finallstClient = new List<SVC.Client>(); for (int j = 0; j < lstClient.Count; j++) { objUtilities = new Utilities(); SVC.Client objClient = new SVC.Client(); objClient.DisplayedImage = ""; objClient.FirstName = lstClient[j].FirstName; objClient.LastName = lstClient[j].LastName; objClient.UserID = lstClient[j].UserID; objClient.PersonalMail = lstClient[j].PersonalMail; objClient.Name = lstClient[j].FirstName + " " + lstClient[j].LastName; objClient.Picture = lstClient[j].Picture; objClient.ImgAlertMsg = ImgAlertMsg; objClient.ImgLogin = ImgLogin; if (lstClient[j].Picture != null) { objClient.DisplayedImage = CreateUserImages(objClient); } else { objClient.DisplayedImage = defaultPath; } finallstClient.Add(objClient); } objGroups.ClientsList = finallstClient; } } finallstGroups.Add(objGroups); } tvGroupUsers.DataContext = finallstGroups;Its urgent Please reply asap...Thanks in Advance..What I have tried:foreach (object parent in items.Items) { TreeViewItem treeItem = this.tvGroupUsers.ItemContainerGenerator.ContainerFromItem(parent) as TreeViewItem; ItemsControl childControl = ItemsControl.ItemsControlFromItemContainer(treeItem); foreach (object child in treeItem.Items) { TreeViewItem childtreeview = this.tvGroupUsers.ItemContainerGenerator.ContainerFromItem(child) as TreeViewItem; } }childtreeview return null 解决方案 Use this Helper method in code behindT GetVisualChild<t>(DependencyObject parent, string name) where T : Visual { T child = default(T); int numVisuals = VisualTreeHelper.GetChildrenCount(parent); for (int i = 0; i < numVisuals; i++) { Visual v = (Visual)VisualTreeHelper.GetChild(parent, i); child = v as T; if (child == null) { child = GetVisualChild<t>(v, name); } if (child != null) { break; } } return child; }</t></t>You just Need isfor eg. Declare Your Image First in your code behind asImage ImgAlert=new Image();in your constructor or Loaded methodthen on your event You can call this method byImgAlert=GetVisualChild<treeview>(this, "ImgAlert");</treeview> 这篇关于无法循环遍历wpf treeview parent及其子节点...我获取父节点值但其子节点返回null值。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！ 上岸，阿里云！