public void ReadOnlyDependencyPropertiesTest()
{
ReadOnlyElement element = new ReadOnlyElement();
Assert.AreEqual(0, element.Value1);
element.SetValue(ReadOnlyElement._private_Value1Key, 1);
Assert.AreEqual(1, element.Value1);
try
{
element.SetValue(ReadOnlyElement.Value1Property, 2);
Assert.Fail();
}
catch (Exception e)
{
Assert.IsTrue(e is Exception);
}
try
{
IDependencyPropertyValueEntry entry = element.GetValueEntry(ReadOnlyElement.Value1Property);
entry.SetBaseValue((int)BaseValueSource.Local, 3);
Assert.Fail();
}
catch (Exception e)
{
Assert.IsTrue(e is Exception);
}
try
{
DependencyPropertyKey fakeKey = new DependencyPropertyKey(ReadOnlyElement.Value1Property);
element.SetValue(fakeKey, 4);
Assert.Fail();
}
catch (Exception e)
{
Assert.IsTrue(e is Exception);
}
try
{
DependencyPropertyKey fakeKey = DependencyProperty.RegisterReadOnly("Value1", typeof(int), typeof(ReadOnlyElement), new PropertyMetadata());
Assert.Fail();
}
catch (Exception e)
{
Assert.IsTrue(e is Exception);
}
}
private void SetValue(DependencyProperty dependencyProperty, DependencyPropertyKey dependencyPropertyKey, object value, bool setCurrentValue = false, BaseValueSource source = BaseValueSource.Unknown)
{
VerifyReadOnlyProperty(dependencyProperty, dependencyPropertyKey);
IExpressionProvider newExpressionProvider = value as IExpressionProvider;
if (newExpressionProvider == null && !dependencyProperty.IsValidValue(value))
{
return; // invalid value
}
IDependencyPropertyValueEntry entry = GetInitializedValueEntry(dependencyProperty);
IExpression oldExpression = setCurrentValue ?
entry.GetBaseValue(false) as IExpression : // current value may be set in the top priority expression
entry.GetBaseValue((int)source, false) as IExpression;
if (newExpressionProvider != null)
{
value = newExpressionProvider.CreateExpression(this, dependencyProperty);
}
else if (oldExpression != null && oldExpression.SetValue(value))
{
return; // value (current or not) was set in the existing expression, nothing else to do
}
if (setCurrentValue)
{
entry.SetCurrentValue(value);
return; // base value isn't changed
}
if (oldExpression is IDisposable) // expression is being replaced
{
((IDisposable)oldExpression).Dispose();
}
entry.SetBaseValue((int)source, value);
entry.ClearCurrentValue();
}
public void SetBaseValue(int priority, object value)
{
source.SetBaseValue(priority, value);
}