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。 [英] Cannot looping through wpf treeview parent and its child node ...i get parent node value but its child return null value.
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问题描述
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 horizontalalignment = 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 horizontalalignment = 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 HorizontalAlignment = 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 < span class =code-attribute> 可见性 = 可见 高度 = 15 < span class =code-attribute>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} < span class =code-attribute> 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：
< pre lang =c＃> 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 behind
T 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 is
for eg. Declare Your Image First in your code behind as
Image ImgAlert=new Image();
in your constructor or Loaded method
then on your event You can call this method by
ImgAlert=GetVisualChild<treeview>(this, "ImgAlert"); </treeview>
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