public void When_Modified_From_Callback_And_TwoWay()
{
var dp1 = new MyDP();
var dp2 = new MyDP();
var binding = new Binding
{
Source = dp1,
Path = new PropertyPath(nameof(MyDP.MyInt)),
Mode = BindingMode.TwoWay
};
BindingOperations.SetBinding(dp2, MyDP.MyIntProperty, binding);
var callbackCount = 0;
dp1.RegisterPropertyChangedCallback(MyDP.MyIntProperty, OnMyIntChanged);
dp2.MyInt = 11;
Assert.AreEqual(42, dp1.MyInt);
Assert.AreEqual(11, dp2.MyInt);
Assert.AreEqual(2, callbackCount);
void OnMyIntChanged(DependencyObject sender, DependencyProperty dpInner)
{
callbackCount++;
(sender as MyDP).MyInt = 42;
}
}
public void When_TwoWay_And_ConvertBack()
{
var dp1 = new MyDP();
var dp2 = new MyDP();
var conv = new IncrementConverter();
var binding = new Binding
{
Source = dp1,
Path = new PropertyPath(nameof(MyDP.MyInt)),
Mode = BindingMode.TwoWay,
Converter = conv
};
BindingOperations.SetBinding(dp2, MyDP.MyIntProperty, binding);
Assert.AreEqual(1, dp2.MyInt);
Assert.AreEqual(1, conv.ConvertCount);
Assert.AreEqual(0, conv.ConvertBackCount);
dp2.MyInt = 7;
Assert.AreEqual(dp2.MyInt, 7);
Assert.AreEqual(dp1.MyInt, 8);
Assert.AreEqual(1, conv.ConvertCount);
Assert.AreEqual(1, conv.ConvertBackCount);
dp1.MyInt = 19;
Assert.AreEqual(19, dp1.MyInt);
Assert.AreEqual(20, dp2.MyInt);
Assert.AreEqual(2, conv.ConvertCount);
Assert.AreEqual(1, conv.ConvertBackCount);
}
public void When_TwoWay_And_ConvertBack_Normal_Binding()
{
var dp1 = new MyDP();
var dp2 = new MyDP();
var conv = new StringToDoubleConverter();
var binding = new Binding
{
Source = dp1,
Path = new PropertyPath(nameof(MyDP.MyDouble)),
Mode = BindingMode.TwoWay,
Converter = conv
};
BindingOperations.SetBinding(dp2, MyDP.MyStringProperty, binding);
Assert.AreEqual("¤0.00", dp2.MyString);
Assert.AreEqual(1, conv.ConvertCount);
Assert.AreEqual(0, conv.ConvertBackCount);
dp2.MyString = "42";
// For normal bindings, the source update through the converter
// is ignored. Therefore, only the ConvertBack method is invoked as
// the UpdateSource method is ignored because a two-way binding is
// in progress. This behavior is different with x:Bind.
Assert.AreEqual("42", dp2.MyString);
Assert.AreEqual(42, dp1.MyDouble);
Assert.AreEqual(1, conv.ConvertCount);
Assert.AreEqual(1, conv.ConvertBackCount);
}
public void When_Modified_From_Callback()
{
var dp = new MyDP();
var callbackCount = 0;
dp.RegisterPropertyChangedCallback(MyDP.MyIntProperty, OnMyIntChanged);
dp.MyInt = 11;
Assert.AreEqual(42, dp.MyInt);
Assert.AreEqual(2, callbackCount);
void OnMyIntChanged(DependencyObject sender, DependencyProperty dpInner)
{
callbackCount++;
(sender as MyDP).MyInt = 42;
}
}
public void When_TwoWay_And_ConvertBack_Normal_xBind()
{
var dp1 = new MyDP();
var dp2 = new MyDP();
var conv = new StringToDoubleConverter();
var binding = new Binding
{
Path = new PropertyPath(nameof(MyDP.MyDouble)),
Mode = BindingMode.TwoWay,
Converter = conv,
CompiledSource = dp1,
};
BindingOperations.SetBinding(dp2, MyDP.MyStringProperty, binding);
dp2.ApplyXBind();
Assert.AreEqual("¤0.00", dp2.MyString);
Assert.AreEqual(1, conv.ConvertCount);
Assert.AreEqual(0, conv.ConvertBackCount);
dp2.MyString = "42";
// For x:Bind, the source update through the converter raises
// a property change, which is in turn sent back to the target
// after another Convert invocation.
//
// There is no loop happening because the binding engine is ignoring
// the UpdateSource invocation as a two-way binding is still happening.
//
// This behavior is different with a normal binding.
Assert.AreEqual("¤42.00", dp2.MyString);
Assert.AreEqual(42, dp1.MyDouble);
Assert.AreEqual(2, conv.ConvertCount);
Assert.AreEqual(1, conv.ConvertBackCount);
}
