c# - 如何使用 lambda 表达式在列表中设置多个值？

Question

如何设置列表对象的多个值，我正在做以下但失败。

objFreecusatomization
.AllCustomizationButtonList
.Where(p => p.CategoryID == btnObj.CategoryID && p.IsSelected == true && p.ID == btnObj.ID)
.ToList()
.ForEach(x => x.BtnColor = Color.Red.ToString(),  );

最后在逗号后我想设置另一个值。应该是什么表达，虽然我只有一条记录相关。

Answer 1

我个人不会这样写代码无论如何 - 但你可以只使用 statement lambda :

A statement lambda resembles an expression lambda except that the statement(s) is enclosed in braces

The body of a statement lambda can consist of any number of statements; however, in practice there are typically no more than two or three.

所以 ForEach 调用看起来像这样:

.ForEach(x => {
    x.BtnColor = Color.Red.ToString();
    x.OtherColor = Color.Blue.ToString();
});

不过我会写一个 foreach 循环:

var itemsToChange = objFreecusatomization.AllCustomizationButtonList
     .Where(p => p.CategoryID == btnObj.CategoryID
                 && p.IsSelected
                 && p.ID == btnObj.ID);

foreach (var item in itemsToChange)
{
    item.BtnColor = Color.Red.ToString();
    item.OtherColor = Color.Blue.ToString();
}

(您可以将查询内联到 foreach 语句本身，但我个人认为使用单独的局部变量的上述方法更清晰。)