Give a name and declare event handler of a button Created at run time with C# XamlReader

问题

I am working on a project in C# and WPF that dynamically creates a grid layout that has some text, an image, and a button. I create many of these grids, and add them to a stack panel. I create this grid using the XamlReader.Create() function. Here is the whole code, and i apologize that the Xaml code is so long

string xaml = "<Grid Height='92' Margin='0,10,0,0' xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>"+
            "<Grid.Background>"+
                "<LinearGradientBrush EndPoint='0.5,1' StartPoint='0.5,0'>"+
                    "<GradientStop Color='#FFACD7FF' Offset='0.172'/>"+
                    "<GradientStop Color='#FFACD7FF' Offset='0.508'/>"+
                    "<GradientStop Color='#FF69B5FF' Offset='0.996'/>"+
                    "<GradientStop Color='#FF79BEFB' Offset='0.017'/>"+
                    "<GradientStop Color='#FFACD7FF' Offset='0.877'/>"+
                "</LinearGradientBrush>"+
            "</Grid.Background>"+
            "<Grid.RowDefinitions>"+
                "<RowDefinition Height='0.522*'/>"+
                "<RowDefinition Height='0.478*'/>"+
            "</Grid.RowDefinitions>"+
            "<Grid.ColumnDefinitions>"+
                "<ColumnDefinition Width='133'/>"+
                "<ColumnDefinition Width='73.5'/>"+
                "<ColumnDefinition Width='0.833*'/>"+
                "<ColumnDefinition Width='0.167*'/>"+
                "<ColumnDefinition Width='108.775'/>"+
            "</Grid.ColumnDefinitions>"+
            "<Image Source='stockHome.jpg' Margin='8' Grid.Column='4' Grid.RowSpan='2'/>"+
            "<TextBlock TextWrapping='Wrap' Text='Details: "+
            addHouse.description+
            "' Margin='8' Grid.Column='2' HorizontalAlignment='Center'/>"+
            "<Button Content='View Full Description' Grid.Column='2' HorizontalAlignment='Center' Margin='4,8,0,8' Grid.Row='1' Width='134.667'/>"+
            "<Label Content='$"+
            addHouse.cost+
            "' Margin='8,8,0,0' FontSize='21.333' FontFamily='Segoe UI Semibold' HorizontalAlignment='Left' RenderTransformOrigin='0.53,1.474'/>"+
            "<Label Content='"+
            addHouse.neighborhood+
            "' Margin='8,0,0,8' Grid.Row='1' HorizontalAlignment='Left' Width='117' FontSize='18.667'/>"+
            "<TextBlock Grid.Column='1' Margin='8,15,8,8' Grid.RowSpan='2' TextWrapping='Wrap'><Run Text='"+
            addHouse.type+
            "'/><LineBreak/><Run Text='"+
            addHouse.bedrooms+
            " Bed'/><LineBreak/><Run Text='"+
            addHouse.bathrooms+
            " Bath'/><LineBreak/><Run Text='ID: "+
            addHouse.ID+
            "'/></TextBlock>"+
            "<Image Grid.Column='3' Margin='8,23.667,8,20.251' Grid.RowSpan='2' Source='HeartPop.png'/>"+
            "</Grid>";  


            // Load the panel
        StringReader stringReader = new StringReader(xaml);
        XmlReader xmlReader = XmlReader.Create(stringReader);
        Grid readerLoadGrid = (Grid)XamlReader.Load(xmlReader);

This has worked fine for me, and i thought this would be the correct way to generate a grid layout at runtime, but now that i need to name the button, and define an event handler, this falls apart. when i try to change the button description to

 <Button x:Name = 'houseButton' Click = 'descriptionButtonClick' ...

I get a XAMLParse exception. After reading about this, i am not so sure that you can declare these things in xaml at runtime. So now, I am very confused on how else to do this. I cant just change the name after i have created the grid, as it has no name to be called by. is there a way to access a child of a UIElement even if it has no name? or is there a way to declare the name in XAML at runtime and im just doing it wrong?

回答1:

You can define the Grid on runtime like you can do it with most other controls. here is a page showing an example how:

http://sullivan.net/blog/2009/09/creating-a-wpf-grid-programmatically-code-behind/

than you'll be able to use button objects and access them using c# like:

Button myBtn = new Button(); Button.Click += new ....

回答2:

You CAN set the Name property of the Button.

//... xaml definition
<Button Name='houseButton' ... />
//... xaml definition

and you can get the button for attaching event to it:

var xamlObj = XmlReader.Create(new StringReader(xamlString));
Grid grid = XamlReader.Load(xamlObj);
var btn = (Button)grid.FindName("houseButton");
btn.Click += ...

来源：https://stackoverflow.com/questions/8398027/give-a-name-and-declare-event-handler-of-a-button-created-at-run-time-with-c-sha

标签

wpf

xaml

xamlparseexception

xamlreader