C# DataGridView not updated when datasource is changed
Quick and dirty solution:
dataGridView.DataSource = null;
dataGridView.DataSource = phase3Results;
Clean and correct solution:
Use a BindingList<T>
instead of List<T>
as your DataSource. List<T>
does not fire events when its collection changes.
Also, if you additionally implement INotifyPropertyChanged
for T
, BindingList<T>
automatically subscribes to property changes for each T
in the collection and lets the view know about the change.
Try using a BindingList<> instead of List<> and (as already suggested by Daniel), implement INotifyPropertyChanged. However, I think you can also call .Refesh() if you didn't want to implement the INotifyPropertyChanged interface.
Here's an example ripped from here
public class Car : INotifyPropertyChanged
{
private string _make;
private string _model;
private int _year;
public event PropertyChangedEventHandler PropertyChanged;
public Car(string make, string model, int year)
{
_make = make;
_model = model;
_year = year;
}
public string Make
{
get { return _make; }
set
{
_make = value;
this.NotifyPropertyChanged("Make");
}
}
public string Model
{
get { return _model; }
set
{
_model = value;
this.NotifyPropertyChanged("Model");
}
}
public int Year
{
get { return _year; }
set
{
_year = value;
this.NotifyPropertyChanged("Year");
}
}
private void NotifyPropertyChanged(string name)
{
if(PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(name));
}
}
_dgCars.AutoGenerateColumns = false;
DataGridViewTextBoxColumn makeColumn = new DataGridViewTextBoxColumn();
makeColumn.DataPropertyName = "Make";
makeColumn.HeaderText = "The Car's Make";
DataGridViewTextBoxColumn modelColumn = new DataGridViewTextBoxColumn();
modelColumn.DataPropertyName = "Model";
modelColumn.HeaderText = "The Car's Model";
DataGridViewTextBoxColumn yearColumn = new DataGridViewTextBoxColumn();
yearColumn.DataPropertyName = "Year";
yearColumn.HeaderText = "The Car's Year";
_dgCars.Columns.Add(makeColumn);
_dgCars.Columns.Add(modelColumn);
_dgCars.Columns.Add(yearColumn);
BindingList<Car> cars = new BindingList<Car>();
cars.Add(new Car("Ford", "Mustang", 1967));
cars.Add(new Car("Shelby AC", "Cobra", 1965));
cars.Add(new Car("Chevrolet", "Corvette Sting Ray", 1965));
_dgCars.DataSource = cars;
You need to implement the INotifyPropertyChanged interface on the object that is storing the data. Each property needs to raise that event during the set call of a property if the value changed. Then the grid will automatically get the update.