神马文学网How get click event from button embedded in each item of ListView...
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How get click event from button embedded in each item of ListView...
I have a ListView control with a DataTemplate for displaying some of the columns. Inside of one DataTemplate, I have a button.
When this button is clicked, how do I get the click event in the main window C# code? Will this event also give me the list view item that was clicked, or will I have to figure that out somehow? The button has a name, but that‘s going to be the same for each row.
Thanks for any help...
Redburga you can use
VisualTreeHelper.GetParent(btn) in a loop to go up the tree
lee dOff the top of my head, you should be able to do this in one of two ways:
- Handle the routed click event on your listview - less resources used at runtime, little more logic needed to check what exactly raised the event originally.
- Put the event handler declaration on your Button in the DataTemplate‘s VisualTree - more costly at runtime because every button will have a delegate attached to it, simpler code in the handler since it designed just for that button
HTH,
Drew
Microsoft C# / WPF MVP Drew Marsh
Thanks for the suggestions, folks.
Since I could have a few hundred, or even a few thousand items in the list, I probably don‘t want option 2.
So suppose I want to get the button click event in the window containing the ListView control. The command should bubble up, so I should be able to get it here.
What code do I need to get the button click event so I can handle it and figure out where it came from? I‘m guessing I just need to grab any button click and then I could check the name of the control to see if it‘s the button I care about, then figure where it came from?
I‘m stuck on the generic event handler code. I don‘t have something like MyButton.Click that I can set an event hander to.
RedburgaDrew, I‘ve thought about your answer a little more...
Is this what you meant by suggestion #2:
<Button Width="16" Height="16" Background="Transparent" Margin="5,0,0,0" Click="EditCommentClick" Name="EditComment" BorderThickness="0,0,0,0" >
I can hande the above using this code:
private void EditCommentClick(object sender, RoutedEventArgs e) {...}
I can then use the VisualTreeHelper.GetParent method that lee suggested. My only concern is if this method causes a delegate to be created for each item in my ListView. I‘m still learning how all this stuff gets hooked up.
Thanks for the help..
Redburgathis is how I did it
<Window x:Class="WindowsApplication1.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="WindowsApplication1" Height="300" Width="500" Loaded="OnLoaded"
>
<Grid Width="400">
<Grid.Resources>
<XmlDataProvider x:Key="InventoryData" XPath="Inventory/Books">
<x:XData>
<Inventory xmlns="">
<Books>
<Book ISBN="0-7356-0562-9" Stock="in" Number="9">
<Title>XML in ActionTitle>
<Summary>XML Web TechnologySummary>
Book>
<Book ISBN="0-7356-1370-2" Stock="in" Number="8">
<Title>Programming Microsoft Windows With C#Title>
<Summary>C# Programming using the .NET FrameworkSummary>
Book>
<Book ISBN="0-7356-1288-9" Stock="out" Number="7">
<Title>Inside C#Title>
<Summary>C# Language ProgrammingSummary>
Book>
<Book ISBN="0-7356-1377-X" Stock="in" Number="5">
<Title>Introducing Microsoft .NETTitle>
<Summary>Overview of .NET TechnologySummary>
Book>
<Book ISBN="0-7356-1448-2" Stock="out" Number="4">
<Title>Microsoft C# Language SpecificationsTitle>
<Summary>The C# language definitionSummary>
Book>
Books>
Inventory>
x:XData>
XmlDataProvider>
<DataTemplate x:Key="res1">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding XPath=@Number}">TextBlock>
<Button >click hereButton>
StackPanel>
DataTemplate>
Grid.Resources>
<ListView Button.Click="clicked1" Width="400" ItemsSource="{Binding Source={StaticResource InventoryData},
XPath=Book}"
HorizontalAlignment="Center"
VerticalAlignment="Center"
Margin="0,20,0,0" Name="myListView2" >
<ListView.View>
<GridView>
<GridViewColumn Header="ISBN"
DisplayMemberBinding="{Binding XPath=@ISBN}" />
<GridViewColumn Header="Stock"
DisplayMemberBinding="{Binding XPath=@Stock}" />
<GridViewColumn Header="Number"
CellTemplate="{StaticResource res1}"/>
GridView>
ListView.View>
ListView>
Grid>
Window>
private DependencyObject GetDependencyObjectFromVisualTree(DependencyObject startObject, Type type)
{
//Iterate the visual tree to get the parent(ItemsControl) of this control
DependencyObject parent = startObject;
while (parent != null)
{
if (type.IsInstanceOfType(parent))
break;
else
parent = VisualTreeHelper.GetParent(parent);
}
return parent;
}
void clicked1(object sender, RoutedEventArgs e)
{
ListViewItem lvi = GetDependencyObjectFromVisualTree(e.OriginalSource as DependencyObject, typeof(ListViewItem)) as ListViewItem;
System.Xml.XmlElement ele = (System.Xml.XmlElement)lvi.Content;
MessageBox.Show("you clicked " + ele.Attributes["ISBN"].Value);
}
lee dThanks for the code 
I didn‘t realize I could put the Button.Click in the ListView declaration. It seems to work.
Now, if I have multiple buttons, I believe the Button.Click event handler will get called, regardless of the button. Is there a way to hook the Button.Click event to a specific button name in the xaml? Otherwise, I suppose I can just find the parent to figure out which one was clicked.
Redburga Actually, I don‘t need to look for the parent to figure out which button it is. I just get the button object and ask its name. Then find the parent ListViewItem and I‘m ready to go! RedburgaHow did you accomplish this? I‘m trying to find the parent ListViewItem
private void clicked1(Object sender, RoutedEventArgs e)
{
Button b = e.OriginalSource as Button;
ListViewItem lvi = this.listView.ItemContainerGenerator.ItemFromContainer(b) as ListViewItem;
}
clauden Hey, Lee, you are just coming a long way to do it, why not just write something like the following in the clicked1 event handler: