两个字符串列表和foreach

Question

我的WebAPI收到两个字符串，一个包含显示值（名称），一个包含隐藏值（电子邮件）。

之前，它只收到一个字符串，它使用了foreach，我不确定如何让它与两个一起工作， 如何填写“nameslist”中的“name” ：

[System.Web.Http.HttpGet]
public AjaxAnswer BatchUserCreate(string email, string names) {
    string[] emaillist = email.Split('\n');
    string[] nameslist = names.Split('\n');
    foreach(string email in emaillist) {
        db.AddParameter("@email",email);
        db.AddParameter("@name",name);
        int newId = db.ExecuteScalar(userInsQuery);
    }
    return new AjaxAnswer(newId);
}

Answer 1

将两个列表压缩在一起

var nameEmailPairs = emaillist.Zip(namelist, (email,name)=>new{email,name});

然后，您可以foreach 知道 ，其中包含名称和电子邮件的项目。

Answer 2

如果您保证这些列表的顺序相同 - 请使用plain for循环：

for(int i=0; i<emaillist.Length; i++) {
    string email = emaillist[i];
    string name = namelist[i];
    ...

或者你可以使用LINQ和Zip ：

var records = emaillist.Zip(namelist, (email, name) => new {email, name});
foreach(var r in records) {
    string email = r.email;
    string name = r.name;
    ...

Answer 3

尝试将foreach循环更改为for循环：

[System.Web.Http.HttpGet]
public AjaxAnswer BatchUserCreate(string email, string names) {
    string[] emaillist = email.Split('\n');
    string[] nameslist = names.Split('\n');

    // You should declare "newId" somewhere here 
    // if you want to return it via "new AjaxAnswer(newId)" 
    int newId = 0;

    // if emaillist and nameslist have diffrent lengths 
    // let's take minimal length
    int n = Math.Min(nameslist.Length, emaillist.Length);

    for (int i = 0; i < n; ++i) {
      db.AddParameter("@email", emaillist[i]);
      db.AddParameter("@name", nameslist[i]);
      newId = db.ExecuteScalar(userInsQuery);
    }

    return new AjaxAnswer(newId);
}

Answer 4

你应该使用for循环，这样的东西可以帮助：

[System.Web.Http.HttpGet]
public AjaxAnswer BatchUserCreate(string email, string names) {
    string[] emaillist = email.Split('\n');
    string[] nameslist = names.Split('\n');
    for(int i = 0; i!=emaillist.Length; ++i) {
        db.AddParameter("@email", emaillist[i]);
        db.AddParameter("@name", nameslist.Length > i ? nameslist[i] : "No name");
        int newId = db.ExecuteScalar(userInsQuery);
    }
    return new AjaxAnswer(newId);
}

Answer 5

如果两个数组（emaillist和nameslist）的长度相等，则应使用for循环而不是foreach循环：

[System.Web.Http.HttpGet]
public AjaxAnswer BatchUserCreate(string email, string names) {
    string[] emaillist = email.Split('\n');
    string[] nameslist = names.Split('\n');

    for(int i = 0; i < emaillist.Length; i++) {
        db.AddParameter("@email",emaillist[i]);
        db.AddParameter("@name",namelist[i]);
        int newId = db.ExecuteScalar(userInsQuery);
    }
    return new AjaxAnswer(newId);
}

Answer 6

尝试这项工作希望它会有所帮助

for(int i =0 ; i< emaillist .count; i++)
{
    db.AddParameter("@email",emaillist[i]);
    db.AddParameter("@name",nameslist[i]);
    int newId = db.ExecuteScalar(userInsQuery);
}