/// <summary>
/// 从表达式中得到值
/// </summary>
/// <param name="expression"></param>
/// <param name="target"></param>
/// <param name="propertyName"></param>
/// <returns></returns>
private static object ProvideValue(string expression, object target, string propertyName)
{
var extension = MarkupExtensionFactory.Create(expression);
if (extension == null)
{
return(expression); //不是标记，直接返回表达式作为值
}
var value = extension.ProvideValue(target, propertyName);
var exp = value as Expression;
if (exp != null)
{
//如果是表达式，那么执行表达式后再获取值
value = exp.GetValue(target, propertyName);
}
return(value);
}
private static MarkupExtension CreateMarkupExtension(string attrValue)
{
return(MarkupExtensionFactory.Create(attrValue));
}
