static Expression <Func <T, bool> > Custom_Expression_Common <T>(ExpressionEventHandler handler, string columnNames, params object[] values)
{
BinaryExpression filter = Expression.Equal(Expression.Constant(1), Expression.Constant(1));
var columns = columnNames.Split(',');
var param = Expression.Parameter(typeof(T));
for (int i = 0; i < columns.Length; i++)
{
if (values[i] == null)
{
continue;
}
string columnName = columns[i].ToString();
var value = values[i];
Expression left = Expression.Property(param, typeof(T).GetProperty(columnName));
Expression right = Expression.Constant(value, value.GetType());
Expression result = handler(left, right);
filter = Expression.And(filter, result);
}
return(Expression.Lambda <Func <T, bool> >(filter, param));
}
public BaseObserver(Control ctrl)
{
this.ExpressionChangedEvent += new ExpressionEventHandler(Observer_ExpressionChangedEvent);
this._ctrl = ctrl;
}
