blocks|key|4374952|text|getline的第二个参数需要是一个字符串：http://www.cplusplus.com/reference/string/string/getline/|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|4374953|我认为你想要达到的目标是：|4374954|ifstream+fruitFile;
fruitFile.open("fruit.txt");
int+line+=+0;
fruitFile+>>+line
fruitFile.close();|code-block|syntax|javascript|4374955|entityMap|0|LINK|mutability|MUTABLE|url|http://www.cplusplus.com/reference/string/string/getline/^0|M|1L|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|C|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

The second argument of getline needs to be a string: <a href="http://www.cplusplus.com/reference/string/string/getline/" rel="nofollow">http://www.cplusplus.com/reference/string/string/getline/</a>

I think what you try to achieve is: 

<pre><code>ifstream fruitFile;
fruitFile.open("fruit.txt");
int line = 0;
fruitFile &gt;&gt; line
fruitFile.close();
</code></pre>

blocks|key|3972302|text|getline()将读取一行文本。它不能直接读取一个int。这就是为什么你会得到你的错误信息。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3972303|您必须知道有两个getline()。有一个是istream::getline()和std::getline()。两者都有不同的签名。第一个是流的成员函数，并在流头中定义；后者在<string>头中定义。|3972304|但是请注意：std::getline()的返回值不是int！这是一个流参考。这就是第二个编译器错误的原因。|3972305|最后，如果要读取整数x，则使用提取器更容易：|3972306|int+value;+
fruitFile+>>+value;+
fruitFile.ignore(SIZE_MAX,+'\n');+++//+in+case+you'd+need+to+go+to+next+line|code-block|syntax|javascript|3972307|或者，如果您真的想阅读整行的int：|3972308|string+line;
getline(fruitFile,+line);+
stringstream+sst(line);+++++//+creates+a+string+stream:+a+stream+that+takes+line+as+input
sst+>>+value;++++++|3972309|entityMap^0|0|9|0|8|9|M|I|15|E|2G|8|0|6|E|Q|3|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]|$9|14|A|15|B|C]|$9|16|A|17|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|18|8|@$9|19|A|1A|B|C]|$9|1B|A|1C|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|1D|8|@]|D|@]|E|$]]|$1|L|3|M|5|N|7|1E|8|@]|D|@]|E|$O|P]]|$1|Q|3|R|5|6|7|1F|8|@]|D|@]|E|$]]|$1|S|3|T|5|N|7|1G|8|@]|D|@]|E|$O|P]]|$1|U|3|-4|5|6|7|1H|8|@]|D|@]|E|$]]]|V|$]]

<code>getline()</code> will read one line of text. It can't read directly an int. This is why you get your error message. 

You have to be aware that there are two <code>getline()</code>. There is one which is <code>istream::getline()</code> and <code>std::getline()</code>. Both have different signatures. The first is a member function of a stream and is defined in the stream header; the latter is defined in the <code>&lt;string&gt;</code> header. 

But pay attention: the return value of <code>std::getline()</code> is not an <code>int</code> ! It's a stream reference. This is why you get a second compiler error. 

Finally if you want to read an integer x, it's easier to use extractors: 

<pre><code>int value; 
fruitFile &gt;&gt; value; 
fruitFile.ignore(SIZE_MAX, '\n'); // in case you'd need to go to next line
</code></pre>

Or if you really want to read an int in a full line: 

<pre><code>string line;
getline(fruitFile, line); 
stringstream sst(line); // creates a string stream: a stream that takes line as input
sst &gt;&gt; value; 
</code></pre>

blocks|key|3972320|text|我也面临同样的错误。将其添加到代码中以解决问题|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3972321|添加string库|ordered-list-item|offset|length|style|CODE|3972322|include+<string>|code-block|syntax|javascript|3972323|添加下面的函数调用，其中string_variable应该是string类型。|3972324|std::getline(cin,+sting_variable)|3972325|entityMap^0|0|2|6|0|0|C|F|U|6|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|U|8|@$E|V|F|W|G|H]]|9|@]|A|$]]|$1|I|3|J|5|K|7|X|8|@]|9|@]|A|$L|M]]|$1|N|3|O|5|D|7|Y|8|@$E|Z|F|10|G|H]|$E|11|F|12|G|H]]|9|@]|A|$]]|$1|P|3|Q|5|K|7|13|8|@]|9|@]|A|$L|M]]|$1|R|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|S|$]]

I faced the same error. add this to your code to solve the problem
<ol>
<li>Add the <code>string</code> library</li>
</ol>
<pre class="lang-cpp prettyprint-override"><code>include &lt;string&gt;
</code></pre>
<ol start="2">
<li>Add the below function call, where <code>string_variable</code> should be of type <code>string</code>.</li>
</ol>
<pre class="lang-cpp prettyprint-override"><code>std::getline(cin, sting_variable)
</code></pre>

I know I know.
This question has been asked before, but I've looked at all the answers and none seem to solve my problem. When I use the getline function to get the contents of a line in the file, it doesn't work.

<pre><code>getline(file, line);
</code></pre>

'File' is declared here:

<pre><code>ifstream File;
File.open("fruit.txt");
</code></pre>

and 'line' is declared here:

<pre><code>int line = 0;
</code></pre>

Getline is underlined in red with this message:

<pre><code>getline
no instance of overloaded function "getline" matches the argument list
argument types are :(std::ifstream, int)
</code></pre>

What this means is no instance of getline has the argument list of the file stream and an integer.

This makes no sense as all the other questions on this matter state exactly that, that the arguments are the file stream and an integer.

What am I doing wrong?

EDIT:

Here is the full code:

<pre><code>ifstream fruitFile;
fruitFile.open("fruit.txt");
int line = 0;
int C_FRUIT = getline(fruitFile, line);
fruitFile.close();
</code></pre>

The first line should be a number, and I need it.

C++ Getline issues (No instance of overloaded function "getline"

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我知道我知道。我以前问过这个问题，但是我看过所有的答案，似乎没有一个能解决我的问题。当我使用getline函数获取文件中一行的内容时，它不起作用。getline(file, line);“‘File”在这里声明：ifstream File;File.open("fruit.txt");“行”在这里声明：int line...

问C++ Getline问题(没有重载函数"getline“的实例)
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