如何根据列表中的元素向列表添加值 [英] How to add values to a list based on the the element present in list

问题描述

我有一个清单

I have a list

Selected objSelectd;// Selected is a class

        List<Selected> objlistSelected = new List<Selected>();

        objSelectd.Image = ImageName;

        objSelectd.strText = ImageHeading;

        objlistSelected.Add(objSelectd);

如果列表objlistSelected包含ImageName，那么我需要添加安装价值

if the list objlistSelected contains ImageName then i need to add Installation value

objSelectd.Installation = "aaaa"

i试过这些并且它不起作用

i have tried these and its not working

objSelectd.Installation = "AAA"
                    if (objlistSelected.Contains(ImageName))
                    {
                        objlistSelected.Add(objSelectd);
                    }

                    for (int i = 0; i < objlistSelected.Length; i++)
                    {
                        if (objlistSelected[i].Contains(myString)) // (you use the word "contains". either equals or indexof might be appropriate)
                        {
                            return i;
                        }
                    }

请帮助

先谢谢

Please help
Thanks in Advance

推荐答案

您需要通过列表中对象的字段进行检查。你不能使用contains，因为它会查找整个对象。

You need to check by a field of the objects in the list. You can't use contains as it will look for the whole object.

if(objlistSelected.Any(x =>x.Image==ImageName))
{
...
}

[更新]

如果你想更新元素，试试这个：

[Update]
If you want to update the element, try this:

var element = objlistSelected.FirstOrDefault(x =>x.Image==ImageName);
if(element != null)
{
   element.Installation = "AAA";
}

请参阅以下 LinqPad [ ^ ]摘录：

See following LinqPad[^] snippet:

class C { public string A {get;set;} public string B {get;set;} };

void Main()
{
    var L = new List<C>() {new C() { A="A1", B="B1"}, new C() { A="A2", B="B2"}};
    L.Dump();

    var X = L.FirstOrDefault(x => x.A == "A2");
    if (X!=null)
    {
        X.B = "BBBBB";
    }
    L.Dump();
}

您可以考虑实施词典或 KeyValuePair 然后您可以通过密钥直接访问该元素，然后更新它。图像名称可以作为键，值将是安装值。

You can think about implementing a Dictionary or KeyValuePair where you can then access the element directly by key and then update it. The image name can act as a key and value will be the installation value.

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