Question

我的答案是肯定的？当时的结果将是相同的。

public bool CustomValidationDublicateName(string sysPriority)
{
    var systemPriories = (this.gridView.Items.SourceCollection as IEnumerable<SystemPriority>).Where(item => item.ID > 0).ToList();
    var selectedItem = this.gridView.SelectedItem as SystemPriority;
    foreach (SystemPriority item in systemPriories)
    {
        if (item.Title == sysPriority && item != selectedItem) 
            return false;
    }           
    return true;
}

public bool CustomValidationDublicateName2(string sysPriority)
{
    var systemPriories = (this.gridView.Items.SourceCollection as IEnumerable<SystemPriority>).Where(item => item.ID > 0).ToList();
    var selectedItem = this.gridView.SelectedItem as SystemPriority;
    return systemPriories.All(item => item.Title != sysPriority || item == selectedItem);
}


public bool CustomValidationDublicateName(string sysPriority)
{
    var systemPriories = (this.gridView.Items.SourceCollection as IEnumerable<SystemPriority>).Where(item => item.ID > 0).ToList();
    var selectedItem = this.gridView.SelectedItem as SystemPriority;
    return systemPriories.All(item => item.Title == sysPriority && item != selectedItem);
}

我的答案是肯定的？当时的结果将是相同的。

Answer 1

是

但是，您应该摆脱ToList()，并合并Where()和All()过滤器：

public bool CustomValidationDublicateName2(string sysPriority)
{
    return (this.gridView.Items.SourceCollection as IEnumerable<SystemPriority>)
         .All(item => item.ID < 0 
                   || item.Title != sysPriority 
                   || item == (SystemPriority)this.gridView.SelectedItem);
}

Answer 2

是的，这些功能是平等的。

查看De Morgan's Laws以了解原因!(A && B) == !A || !B。然后你会看到条件做同样的事情。

!(item.Title == sysPriority && item != selectedItem)
    ==
(item.Title != sysPriority || item == selectedItem)

这些功能在逻辑上是否相同？

2 个答案: