WPF中下列代码中运行出来滚动条怎么不出来，求大神解答，谢谢！
前台代码，Name=canGroupInfoContent的Canvas里面的内容是动态添加的，为什么超过好多了还不显示？
<Grid Width="494">
<Border BorderThickness="1" BorderBrush="LightBlue">
<!--Height="279" Width="494"-->
<ScrollViewer HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Auto">
<Canvas>
<Canvas Height="26" Name="canGroupInfoHeader" Background="LightGray" Width="494" VerticalAlignment="Top" MouseLeftButtonUp="Canvas_MouseLeftButtonUp">
<Label Content="+ 图组信息" Height="26" HorizontalAlignment="Left" Margin="10,0,0,0" Name="lbGroupInfo" VerticalAlignment="Top" />
</Canvas>
<Canvas Canvas.Top="26" Visibility="Hidden" Name="canGroupInfoContent">
<Border Width="128" Height="24">
<TextBox IsReadOnly="True" Text="图组名" TextAlignment="Center" />
</Border>
<Border Canvas.Left="128" Width="366" Height="24">
<TextBox Text="" />
</Border>
<Border Canvas.Top="24" Width="128" Height="24">
<TextBox IsReadOnly="True" Text="图组名" TextAlignment="Center" />
</Border>
<Border Canvas.Top="24" Canvas.Left="128" Width="366" Height="24">
<TextBox Text="" />
</Border>
</Canvas>
<Canvas Height="26" Width="494" Name="canFileInfoHeader" Background="LightGray" Canvas.Top="26" MouseLeftButtonUp="Canvas_MouseLeftButtonUp">
<Label Content="+ 文件信息" Height="26" HorizontalAlignment="Left" Margin="10,0,0,0" Name="lbFileInfo" VerticalAlignment="Top" />
</Canvas>
<Canvas Canvas.Top="52" Name="canFileInfoContent" Visibility="Hidden"></Canvas>
</Canvas>
</ScrollViewer>
</Border>
</Grid>
后台代码：
double top = 0;
private void Canvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
Canvas can = sender as Canvas;
if (can != null)
{
switch (can.Name)
{
case "canGroupInfoHeader":
if (canGroupInfoContent.Visibility == System.Windows.Visibility.Hidden)
{
canGroupInfoContent.Visibility = System.Windows.Visibility.Visible;
lbGroupInfo.Content = "- 基本信息";
XmlDocument xmlDoc = new XmlDocument();
string strPath = System.Environment.CurrentDirectory;
string xmlPath = System.IO.Path.Combine(strPath, @"XML\WordCoding.xml");
if (File.Exists(xmlPath) == false)
{
MessageBox.Show("没有找到配置文件请检查！", "系统提示");
return;
}
xmlDoc.Load(xmlPath);
XmlNodeList InforMation = xmlDoc.DocumentElement.SelectNodes("Information/basic");
foreach (XmlNode info in InforMation)
{
Border border = new Border();
border.Width = 128;
border.Height = 24;
//border.SetValue(Canvas.LeftProperty, 128);
border.SetValue(Canvas.TopProperty, top);
TextBox textbox = new TextBox();
textbox.IsReadOnly = true;
textbox.Text = info.Attributes["name"].Value;
textbox.TextAlignment = TextAlignment.Center;
border.Child = textbox;
Border border1 = new Border();
border1.Width = 366;
border1.Height = 24;
border1.SetValue(Canvas.LeftProperty, (double)128);
border1.SetValue(Canvas.TopProperty, top);
TextBox textbox1 = new TextBox();
// textbox1.Name = info.Attributes["value"].Value.ToString();
border1.Child = textbox1;
canGroupInfoContent.Children.Add(border);
canGroupInfoContent.Children.Add(border1);
top = top + 24;
}
canFileInfoHeader.SetValue(Canvas.TopProperty, top);
//ScrollViewer.SetHorizontalScrollBarVisibility(Orientation.Vertical,ScrollBarVisibility.Visible);
}
else
{
canGroupInfoContent.Visibility = System.Windows.Visibility.Hidden;
lbGroupInfo.Content = "+ 基本信息";
canFileInfoHeader.SetValue(Canvas.TopProperty, (double)26);
top = 0;
}
break;
case "canFileInfoHeader":
if (canFileInfoContent.Visibility == System.Windows.Visibility.Hidden)
{
canFileInfoContent.Visibility = System.Windows.Visibility.Visible;
lbFileInfo.Content = "- 文件详细信息";
XmlDocument xmlDoc = new XmlDocument();
string strPath = System.Environment.CurrentDirectory;
string xmlPath = System.IO.Path.Combine(strPath, @"XML\WordCoding.xml");
if (File.Exists(xmlPath) == false)
{
MessageBox.Show("没有找到配置文件请检查！", "系统提示");
return;
}
xmlDoc.Load(xmlPath);
XmlNodeList InforMation = xmlDoc.DocumentElement.SelectNodes("Information/FileBasic");
double top = 0;
foreach (XmlNode info in InforMation)
{
Border border = new Border();
border.Width = 128;
border.Height = 24;
//border.SetValue(Canvas.LeftProperty, 128);
border.SetValue(Canvas.TopProperty, top);
TextBox textbox = new TextBox();
textbox.IsReadOnly = true;
textbox.Text = info.Attributes["name"].Value;
textbox.TextAlignment = TextAlignment.Center;
border.Child = textbox;
Border border1 = new Border();
border1.Width = 366;
border1.Height = 24;
border1.SetValue(Canvas.LeftProperty, (double)128);
border1.SetValue(Canvas.TopProperty, top);
TextBox textbox1 = new TextBox();
// textbox1.Name = info.Attributes["value"].Value.ToString();
border1.Child = textbox1;
canFileInfoContent.Children.Add(border);
canFileInfoContent.Children.Add(border1);
top = top + 24;
}
//canFileInfoHeader.SetValue(Canvas.TopProperty, top);
//canFileInfoHeader.SetValue(Canvas.TopProperty, (double)(26 + 48));
}
else
{
canFileInfoContent.Visibility = System.Windows.Visibility.Hidden;
lbFileInfo.Content = "+ 文件详细信息";
//canFileInfoHeader.SetValue(Canvas.TopProperty, (double)26);
}
break;
}
}
[解决办法]
第一层的Canvas需要设置高度或最小高度。
