C# 赋值的左侧必须是变量
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left hand side of an assignment must be a variable
提问by farhang67
Trying to put an integer data from database(Linq to sql) into a label getting this error exception:
尝试将数据库（Linq 到 sql）中的整数数据放入标签中，出现此错误异常：
left-hand side of an assignment must be a variable property or indexer
赋值的左侧必须是变量属性或索引器
Code:
代码：
protected void Page_Load(object sender, EventArgs e)
{
DataClassesDataContext data = new DataClassesDataContext();
var visit = (from v in data.SeeSites where v.Date == todaydate select v).FirstOrDefault();
int seennow = visit.See; // On This line I can put data in seenow variable, no problem
Convert.ToInt64(lblSeeNow.Text) = visit.See; // exception error appears here
}
采纳答案by Yuriy Galanter
Try:
尝试：
if (visit.See != null) {
lblSeeNow.Text = visit.See.ToString();
}
You cannot assign something toa function result. In your case lblSeeNow.Textis of type String hence usage of ToString(); method of your Int value.
你不能分配的东西给一个函数的结果。在您的情况下lblSeeNow.Text是 String 类型，因此使用 ToString(); 你的 Int 值的方法。
回答by Satpal
You need to use
你需要使用
lblSeeNow.Text = visit.See.ToString();
回答by Smeegs
Convert.ToInt64(lblSeeNow.Text) = visit.See;
As you mentioned, this is the issue.
正如你提到的，这就是问题所在。
Convert.ToInt64is a method. But you're trying to save a value to it.
Convert.ToInt64是一种方法。但是您正在尝试为它保存一个值。
You can't.
你不能。
Just do this
就这样做
lblSeeNow.Text = visit.See.ToString();
回答by Esteban Elverdin
You should convert the integer to string, also add a check for being sure that visit is not null
您应该将整数转换为字符串，并添加检查以确保访问不为空
lblSeeNow.Text = visit != null ? visit.See.ToString() : string.Empty
回答by JBrooks
I think you want
我想你想要
lblSeeNow.Text = visit.See.ToString();
You can't assign anything to
你不能分配任何东西
Convert.ToInt64(lblSeeNow.Text)
because it evaluates to a number.
因为它的计算结果是一个数字。
回答by Becuzz
Convert.ToInt64(lblSeeNow.Text) isn't a variable. It takes the value in lblSeeNow.Text and converts it to a long. There isn't a variable to store stuff in anymore.
Convert.ToInt64(lblSeeNow.Text) 不是变量。它采用 lblSeeNow.Text 中的值并将其转换为 long。没有一个变量来存储东西了。
You probably want this:
你可能想要这个：
lblSeeeNow.Text = visit.See.ToString();
