0
下面是完整的程序（XAML和後面的代碼）。在啓動時，你會看到： 
如何獲取Canvas.SetTop以處理ItemsCollection項目？
當你點擊[顯示/隱藏]你看： 
當您取消家庭和文件，然後單擊[應用]你看： 
由於您可以看到，「主頁」和「文檔」文件夾消失，但其他文件夾不會向上移動。查看兩個列表框，您會看到每行三個項目，文件夾標籤，Canvas.SetTop的值以及True：Visibility.Visible或False：Visibility.Collapsed。原始展示位置列表框是原始值。每次點擊[應用]時，新安置列表框會顯示新值。 Visibility值被應用並且結果是可見的，或者文件夾在那裏或不是。但是，應用Canvas.SetTop不起作用。你可以看到Canvas.SetTop的值已經改變。而且，如果你看一下代碼，你會看到，由於能見度應用到它應用到相同的UIElement：
var f = Me[i];
Canvas.SetTop(iec, f.Top); // Why does this not work and
iec.Visibility = f.FolderVisible; // this does work?
我需要的是可見的文件夾上移採取這些的地方，崩潰了。 Canvas.SetTop不起作用。我怎樣才能讓文件夾移動？
這裏是Solution Explorer窗格中，讓你知道什麼是需要： 
這裏是XAML：
<Window x:Class="FolderTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:system="clr-namespace:System;assembly=mscorlib"
xmlns:local="clr-namespace:FolderTest"
Title="Folder Test"
Width="450"
Height="410">
<Grid Margin="10">
<StackPanel Orientation="Horizontal">
<StackPanel Orientation="Vertical">
<!-- Folder Show/Hide Button -->
<Button Name="FolderOptions" Content="Show/Hide" FontSize="8" FontWeight="Bold" Width="50" Height="20" Margin="116, 0, 0, 0" Click="Event_ShowHide_ButtonClick" />
<!-- Folders -->
<Grid>
<Canvas Name="xFolders"
Width="170"
Height="309"
VerticalAlignment="Top"
HorizontalAlignment="Left"
Margin="0,10,0,0">
<Canvas.Resources>
<local:Folders x:Key="myFolders" />
</Canvas.Resources>
<ItemsControl ItemsSource="{Binding Source={StaticResource myFolders}}">
<ItemsControl.Template>
<ControlTemplate>
<ItemsPresenter />
</ControlTemplate>
</ItemsControl.Template>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Canvas />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<DataTemplate.Resources>
</DataTemplate.Resources>
<Canvas Name="FolderCanvas"
Tag="{Binding Path=Number}"
Visibility="{Binding Path=FolderVisible}">
<Path Data="{Binding Path=FolderPath}"
Stroke="{Binding Path=Brush}"
Fill="{Binding Path=Brush}"/>
<StackPanel Orientation="Horizontal"
Canvas.Left="5"
Canvas.Top="2">
<TextBlock Text="{Binding Path=Label}"
FontSize="12"
Margin="20, 0, 0, 0" />
</StackPanel>
</Canvas>
</DataTemplate>
</ItemsControl.ItemTemplate>
<ItemsControl.ItemContainerStyle>
<Style>
<Setter Property="Canvas.Top"
Value="{Binding Top}" />
</Style>
</ItemsControl.ItemContainerStyle>
</ItemsControl>
</Canvas>
</Grid>
</StackPanel>
<StackPanel Orientation="Vertical" Margin="10, 0, 0, 0">
<TextBlock Text="Original Placemet:" />
<ListBox Name="OriginalPlacement" />
<Button Name="Refresh" Content="New Placemet:" Margin="0, 10, 0, 0" Click="Event_OriginalPlacement_ButtonClick" />
<ListBox Name="NewPlacement" />
</StackPanel>
</StackPanel>
</Grid>
</Window>
下面是C＃代碼背後：
using System;
using System.Collections.Generic;
using System.Windows.Media;
using System.Windows.Controls;
using System.Windows;
using System.Collections.ObjectModel;
using System.Windows.Controls.Primitives;
using System.Windows.Input;
namespace FolderTest
{
public struct GD
{
public static MainWindow MainWindow = null;
public static Button Refresh = null;
}
public partial class MainWindow : Window
{
public MainWindow()
{
GD.MainWindow = this;
InitializeComponent();
Loaded += new RoutedEventHandler(MainWindow_Loaded);
}
void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
GD.Refresh = Refresh;
Folders.Placement(ref OriginalPlacement);
}
private void Event_ShowHide_ButtonClick(object sender, RoutedEventArgs e)
{
var pu = Folders.FolderShowPopUp();
pu.PlacementTarget = FolderOptions;
pu.IsOpen = true;
}
private void Event_OriginalPlacement_ButtonClick(object sender, RoutedEventArgs e)
{
Folders.Placement(ref NewPlacement);
}
}
public class Folder
{// Specification for each folder tab seen on the left.
public int Number { get; set; } // Folder sequence number top to bottom starging with 1.
public string Label { get; set; } // The label that appears on the folder tab itself.
public double Top { get; set; } // Position of the upper left corner of this folder.
public SolidColorBrush Brush { get; set; } // Solid Color Brush.
public string FolderPath { get; set; } // Contains the geometric path to draw this folder and its tab.
public Visibility FolderVisible { get; set; } // This folder's Show/Hide flag.
public Folder(int Number, string Label, double Top, SolidColorBrush Brush, string FolderPath, Visibility FolderVisible)
{
this.Number = Number;
this.Label = Label;
this.Top = Top;
this.Brush = Brush;
this.FolderPath = FolderPath;
this.FolderVisible = FolderVisible;
}
}
public class Folders : ObservableCollection<Folder>
{
public static ObservableCollection<Folder> Me = null;
private static string[] Labels = new string[]
{
"Personal",
"Health",
"Finances",
"Home",
"Employment",
"Insurance",
"Documents",
"Contacts",
"Journal"
};
private static Dictionary<string, Tuple<bool, bool>> LabelData = new Dictionary<string, Tuple<bool, bool>>()
{// Label Show Hidable
{Labels[0], new Tuple<bool, bool>(true, false)},
{Labels[1], new Tuple<bool, bool>(true, true)},
{Labels[2], new Tuple<bool, bool>(true, true)},
{Labels[3], new Tuple<bool, bool>(true, true)},
{Labels[4], new Tuple<bool, bool>(true, true)},
{Labels[5], new Tuple<bool, bool>(true, true)},
{Labels[6], new Tuple<bool, bool>(true, true)},
{Labels[7], new Tuple<bool, bool>(true, false)},
{Labels[8], new Tuple<bool, bool>(true, true)}
};
private static string[] FolderColors = new string[]
{
"FF36579E",
"FFDF2024",
"FF16A146",
"FF00B2D4",
"FFF47B20",
"FF9F1F63",
"FF13A89E",
"FFB7B7E7",
"FF50CAF5",
"FFAA9E74",
"FF86787D",
"FF36D146",
};
private static byte[] ARGBColor = new byte[4]; // Byte array for the folder top color.
private static void ColorString2ARGB(ref byte[] bytes, string Hex)
{// Converts 8 char hex string to 4 byte array.
for (int i = 0; i < 8; i += 2)
bytes[i/2] = Convert.ToByte(Hex.Substring(i, 2), 16);
}
private static int colorIndex = -1; // Initial value of the colorIndex.
private static string NextColor()
{// Returns a 8 char string containing the next top FolderColor. If at end, cycle to beginning.
colorIndex++;
if (colorIndex >= FolderColors.Length) colorIndex = 0;
return FolderColors[colorIndex];
}
private class FolderShow
{
public string Label { get; set; }
public bool Show { get; set; }
public bool Hidable { get; set; }
public FolderShow(string label, bool show, bool hidable)
{
Label = label;
Show = show;
Hidable = hidable;
}
}
private static List<FolderShow> FolderShowList = null;
public static Popup FolderShowPopUp()
{
var pu = new Popup()
{
Placement = PlacementMode.Right,
AllowsTransparency = true,
StaysOpen = false
};
var b = new Border()
{
BorderThickness = new Thickness(2),
BorderBrush = new SolidColorBrush() { Color = Colors.Black },
CornerRadius = new CornerRadius(5),
Background = new SolidColorBrush() { Color = Colors.White }
};
var sp = new StackPanel()
{
Orientation = Orientation.Vertical,
Margin = new Thickness(10)
};
var tb = new TextBlock()
{
Text = "Checked Folders will be Displayed: ",
FontSize = 16,
FontWeight = FontWeights.Bold,
};
sp.Children.Add(tb);
foreach (var fs in FolderShowList)
{
var cb = new CheckBox()
{
Content = fs.Label,
IsChecked = fs.Show,
IsEnabled = fs.Hidable,
FontSize = 14,
FontWeight = FontWeights.Bold,
Margin = new Thickness(0, 5, 0, 0)
};
cb.Click += new RoutedEventHandler(Event_CheckBoxFolderList_Click);
sp.Children.Add(cb);
}
var bp = new StackPanel()
{
Orientation = Orientation.Horizontal,
Margin = new Thickness(0, 5, 0, 0)
};
var ba = new Button() { Content = "Apply", Width = 50, Height = 25, BorderBrush = new SolidColorBrush(Colors.Transparent), Tag = pu };
ba.Click += new RoutedEventHandler(Event_ApplyFolderList_Click);
bp.Children.Add(ba);
var bc = new Button() { Content = "Cancel", Width = 50, Height = 25, BorderBrush = new SolidColorBrush(Colors.Transparent), Tag = pu, Margin = new Thickness(7, 0, 0, 0) };
bc.Click += new RoutedEventHandler(Event_CancelFolderList_Click);
bp.Children.Add(bc);
sp.Children.Add(bp);
var tbm = new TextBlock()
{
Text = "Disabled folders cannot be hidden.",
Margin = new Thickness(0, 5, 0, 0),
FontSize = 12,
Foreground = new SolidColorBrush() { Color = Colors.Red }
};
sp.Children.Add(tbm);
b.Child = sp;
pu.Child = b;
return pu;
}
private static void Event_CheckBoxFolderList_Click(object sender, RoutedEventArgs e)
{
var cb = (CheckBox)e.Source;
foreach (var fs in FolderShowList)
{
if (fs.Label == cb.Content as string)
{
fs.Show = (bool)cb.IsChecked;
break;
}
}
}
private static void Event_CancelFolderList_Click(object sender, RoutedEventArgs e)
{
((Popup)((Button)e.Source).Tag).IsOpen = false;
}
private static void Event_ApplyFolderList_Click(object sender, RoutedEventArgs e)
{
foreach (var fs in FolderShowList)
{
var sh = LabelData[fs.Label];
LabelData[fs.Label] = new Tuple<bool, bool>(fs.Show, sh.Item2);
}
((Popup)((Button)e.Source).Tag).IsOpen = false;
int p = 0;
foreach (var f in Me)
{
var fs = LabelData[f.Label].Item1 == true;
f.Top = p * folderPositionFactor;
f.FolderVisible = fs ? Visibility.Visible : Visibility.Collapsed;
if (fs) p += 1;
}
foreach (ItemsControl ic in GD.MainWindow.xFolders.Children)
{
for (int i = 0; i < ic.Items.Count; i++)
{
var ie = (UIElement)ic.ItemContainerGenerator.ContainerFromIndex(i);
var iec = Controls.FindChildByType<Canvas>(ie, "FolderCanvas");
if (iec != null)
{
var f = Me[i];
Canvas.SetTop(iec, f.Top); // Why does this not work and
iec.Visibility = f.FolderVisible; // this does work?
}
}
break;
}
GD.Refresh.RaiseEvent(new RoutedEventArgs(Button.ClickEvent));
}
public static void Placement(ref ListBox lb)
{
lb.Items.Clear();
foreach (ItemsControl ic in GD.MainWindow.xFolders.Children)
{
for (int i = 0; i < ic.Items.Count; i++)
{
var ie = (UIElement)ic.ItemContainerGenerator.ContainerFromIndex(i);
var iec = Controls.FindChildByType<Canvas>(ie, "FolderCanvas");
if (iec != null)
{
var f = Me[i];
lb.Items.Add(f.Label + ": " + f.Top.ToString() + ", " + (f.FolderVisible == Visibility.Visible ? "True" : "False"));
}
}
break;
}
}
public Folders()
{// The constructor, initializes itself by creating a folder for each label in Labels
FolderShowList = new List<FolderShow>();
for (int i = 0; i < Labels.Length; i++)
{
string n = Labels[i];
bool h = LabelData[Labels[i]].Item2;
bool s = h == true ? LabelData[Labels[1]].Item1 == true : true;
FolderShowList.Add(new FolderShow(n, s, h));
}
SetFolders();
Me = this;
}
const double folderPositionFactor = 31; // 21.80;
public void SetFolders()
{
SolidColorBrush[] scb = new SolidColorBrush[Labels.Length]; // Hold the linear solid color brush to assign to the folder.
Color[] pointerColor = new Color[Labels.Length]; // Hold the color to assign to the folder's solid color brush.
for (int i = 0; i < Labels.Length; i++)
{// Create a solid color brush for each folder.
ColorString2ARGB(ref ARGBColor, NextColor()); // Color into byte array.
Color TmpColor = Color.FromArgb(ARGBColor[0], ARGBColor[1], ARGBColor[2], ARGBColor[3]); // Create top color.
pointerColor[i] = TmpColor;
SolidColorBrush TmpSCB = new SolidColorBrush() { Color = TmpColor };
scb[i] = TmpSCB; // Assign the solid color brush.
}
// All is ready to create the individual folders.
const string folderHeight = "56"; // "44";
Brush FontColor = Brushes.Black; // Initial font color for labels.
string fp = "M0,7 A7,7 90 0 1 7,0 L100,0 105,18 150,18 150,FH 0,FH Z".Replace("FH", folderHeight); // Initial geometric path for folder design.
int afp = 0; // Actual Folder Position.
for (int i = 0; i < Labels.Length; i++)
{// Create the individual folders.
bool fs = FolderShowList[i].Show;
Add(new Folder(
i + 1, // Folder sequence count.
Labels[i], // Folder label.
afp * folderPositionFactor, // Position of top of folder.
scb[i % scb.Length], // Solid color brush.
fp, // Geometric path for folder design.
fs ? Visibility.Visible : Visibility.Collapsed // User Hidden.
)
);
if (fs) afp += 1;
if (i == 0)
{// First folder created, now set values for remaining folders.
FontColor = Brushes.White;
fp = "M0,25 A7,7 90 0 1 7,18 L13,18 18,0 100,0 105,18 150,18 150,FH 0,FH Z".Replace("FH", folderHeight);
}
}
}
}
public static class Controls
{
public static T FindChildByType<T>(DependencyObject parent, string childName) where T : DependencyObject
{
if (parent == null) return null; // No parent, get out of here.
T foundChild = null;
int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < childrenCount; i++)
{
var child = VisualTreeHelper.GetChild(parent, i);
// If the child is not of the request child type child
T childType = child as T;
if (childType == null)
{
// recursively drill down the tree
foundChild = FindChildByType<T>(child, childName);
// If the child is found, break so we do not overwrite the found child.
if (foundChild != null) break;
}
else if (!string.IsNullOrEmpty(childName))
{
var frameworkElement = child as FrameworkElement;
// If the child's name is set for search
if (frameworkElement != null && frameworkElement.Name == childName)
{
// if the child's name is of the request name
foundChild = (T)child;
break;
}
}
else
{
// child element found.
foundChild = (T)child;
break;
}
}
return foundChild;
}
}
}
感謝您提供的任何幫助。
的'ItemsControl'包裝在'ContentPresenter'每個元素，你需要確保你設置'Canvas.Top'在'ContentPresenter'，而不是在'ItemTemplate'內的項目。這就是'ItemContainerStyle'的作用 - 它在'ContentPresenter'上設置值 – Rachel