There is a simple method that allows us to find a control from the code-behind (android’s activity): findViewById();
Remember to use setContentView(someLayout) before calling the find function to allow the controls to build themselves.
Find a button and bind an acion to it:
final Button button = (Button) findViewById(R.id.button_id);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//some action
}
});
The problem is that we want to bind a field from a custom object. This field is of type different from string (we could use DataGridTextColumn and set its binding like this:
DataGridColumns.Add(new DataGridTextColumn());
((DataGridBoundColumn) DataGridColumns[DataGridColumns.Count - 1]).Binding = new Binding() {Path = new PropertyPath("A")}; )
The only other Column type in SL4 is DataGridTemplateColumn. So we have to create a template, insert a TextBox into it and bind its text to our property. The solution looks as follows:
DataGridColumns.Add(new DataGridTemplateColumn());
string templateString = "<DataTemplate x:Key=\"CustomDataGridColumnTemplate\" "
+ "xmlns=\"http://schemas.microsoft.com/winfx/2006/xaml/presentation\" "
+ "xmlns:x=\"http://schemas.microsoft.com/winfx/2006/xaml\" >"
+ "<TextBox Name=\"CustomTextBox\" Text=\"{Binding [0]}\" />"
+ "</DataTemplate>";
templateString = templateString.Replace("[0]", "A");
DataTemplate mycolumntemplate = XamlReader.Load(templateString) as DataTemplate;
((DataGridTemplateColumn) DataGridColumns[DataGridColumns.Count - 1]).CellTemplate = mycolumntemplate;
DataGridColumns[DataGridColumns.Count - 1].Header = browserColumn.Name;
DataGridColumns[DataGridColumns.Count - 1].Width = DataGridLength.Auto;
Note: You don’t need to include any namespaces if you don’t use x:Name etc.
The problem lies in editing DataGrid style. When you wrap:
<sdk:DataGridCellsPresenter Name="CellsPresenter" />
with a border the header in not synchronized with the body of the grid anymore. The simple solution to this problem is to move:
sdk:DataGridFrozenGrid.IsFrozen="True"
from the Cells presenter to the most outer element you wrap the grid body with. Complete solution with Grid border looks like this:
<!-- CellPresenter content part -->
<Border BorderBrush="Black" BorderThickness="0.25" Controls:Grid.Column="1" sdk:DataGridFrozenGrid.IsFrozen="True">
<sdk:DataGridCellsPresenter Name="CellsPresenter" />
</Border>
When writing CustomValidation remember to include memberNames in ValidationResult. ValidationResult.MemberNames include property names which are validated at a given moment (are connected to the validation result which we received).
Sample validation should look like the following:
public class CustomValidationMethods
{
public static ValidationResult SthNumberValidation(string name, ValidationContext validationContext)
{
string[] memberNames = new string[] { validationContext.MemberName };
if (name.StartsWith("B"))
return ValidationResult.Success;
else
return new ValidationResult("Name does not begin with 'B'", memberNames);
}
}
Never try to use elements of Items collection of ComboBox directly and add them to a GRID like this:
SomeCellContainer.Add(SomeComboItems[iter]);
Everything works fine until you need to change the selected Item. When you press on the ComboBox (Silverlight behaviour) the application crashes with System.InvalidOperationException: Element is already the child of another element.
The purpose of this sample code is to create a DataGrid which rows can be expanded. In others words a combination of DataGrid and a TreeList.
Original post is available here:
I just converted the project from VS2008 to VS2010&SL4:
http://sites.google.com/site/bkosarzyckistorage1/HierarchicalGridDemoVisualStudio2010.7z
