blocks|key|1928323|text|通过这种方式Convert.ToInt32(str_val[0])，您将读取字符串索引处的字符，该字符串将字符转换为整型。int是它的ascii。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1928324|entityMap^0|6|R|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

By doing this way <code>Convert.ToInt32(str_val[0])</code> you are reading the character at a index of the string that converts the char to int. the int is the ascii for it

blocks|key|3565484|text|您试图解析一个字符串，但传入了一个char。首先将字符转换为字符串。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3565485|int+prefix+=+Convert.ToInt32(str_val[0].ToString());|code-block|syntax|javascript|3565486|因此，字符值8是ASCII值56，您要做的是将该值解释为字符串而不是ASCII值。通过使用.ToString()方法，您可以将字符转换为可由ToInt32方法读取的以null结尾的字符串。|3565487|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Your trying to parse a string but passing in a char. Convert the character to a string first. 

<pre><code>int prefix = Convert.ToInt32(str_val[0].ToString());
</code></pre>

So the character value of 8 is the ASCII value 56, what you want to do is inteprete the value as a string rather than an ASCII Value. By using the .ToString() method you are converting the character into a null terminated string, which can be read by the ToInt32 method.

blocks|key|3565541|text|如果您使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3565542|Convert.ToInt32(str_val[0]);|code-block|syntax|javascript|3565543|那么你实际上是在调用重载：|3565544|Convert.ToInt32(char+val);|3565545|它给出了作为参数传递的Unicode/Ascii字符数。|3565546|如果您想转换第一个字符，则需要强制其为字符串类型：|3565547|Convert.ToInt32(str_val.Substring(0,+1));|3565548|这样，您就可以调用重载：|3565549|Convert.ToInt32(string+val);|3565550|它实际上做了您想要做的事情(将字符串值转换为该字符串表示的int值)。|3565551|entityMap^0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|10|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|12|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|A|$]]|$1|O|3|P|5|D|7|14|8|@]|9|@]|A|$E|F]]|$1|Q|3|R|5|6|7|15|8|@]|9|@]|A|$]]|$1|S|3|T|5|D|7|16|8|@]|9|@]|A|$E|F]]|$1|U|3|V|5|6|7|17|8|@]|9|@]|A|$]]|$1|W|3|-4|5|6|7|18|8|@]|9|@]|A|$]]]|X|$]]

If you use:

<pre><code>Convert.ToInt32(str_val[0]);
</code></pre>

then you are actually calling the overload:

<pre><code>Convert.ToInt32(char val);
</code></pre>

which gives the Unicode/Ascii number of character being passed as a parameter.

If you want to convert first character, you need to force it to be a string type:

<pre><code>Convert.ToInt32(str_val.Substring(0, 1));
</code></pre>

This way you call the overload:

<pre><code>Convert.ToInt32(string val);
</code></pre>

which actually do what you want (convert string value to int value that this string represents).

blocks|key|2018243|text|就像Bridge提到的，它正在获取ASCII值。当您在string类上使用索引器仅获取一个字符时，它会将其作为char返回。如果您阅读char+documentation，您将看到它在内部存储为一个数字UTF-16值。它还具有与大多数数字类型的隐式转换，这些类型提取UTF-16值，或将数字形式转换为字符形式。这就是你要做的。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2018244|您要做的是将其解析为一个int，而不是获得UTF-16值的数字表示。这就是所有转换答案的用武之地。|2018245|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/system.char%2528v=VS.90%2529.aspx^0|1V|I|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@$A|O|B|P|1|Q]]|C|$]]|$1|D|3|E|5|6|7|R|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]]]

Like Bridge mentioned, it's getting the ASCII value. When you use the indexer on the string class to get just a character, it returns it as a char. If you read the <a href="http://msdn.microsoft.com/en-us/library/system.char%28v=VS.90%29.aspx" rel="nofollow">char documentation</a> you'll see that it is internally stored as a numeric UTF-16 value. It also has implicit conversions to and from most numeric types, which extract the UTF-16 value, or convert the numeric form into the character form. That's what you're doing.

What you mean to do is parse it as an int, not get the numeric representation of the UTF-16 value. That's where the Convert answers all come in.

blocks|key|2018116|text|Int32.Parse(str_val[0])|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|2018117|将给出字符串形式的数字。|unstyled|2018118|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>Int32.Parse(str_val[0])
</code></pre>

Will give you number in string.

<pre><code>static void Main(string[] args)
{
 string str_val = "8584348,894";
 //int prefix = Convert.ToInt32(str_val[0]); //prefix = 56 O_o
 //int prefix = (int)str_val[0]; //what, again 56? i need 8!
 int prefix = Convert.ToInt32("8"); //at least this works -_-
}
</code></pre>

Any idea how to convert first symbol to right numeric value?

Trying to convert first symbol of string to int, getting weird value

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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static void Main(string[] args){    string str_val = "8584348,894";    //int prefix = Convert.ToInt32(str_val[0]); //prefix = 56 O_o    //int prefix = (int)str_...

问尝试将字符串的第一个符号转换为int，得到奇怪的值
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问尝试将字符串的第一个符号转换为int，得到奇怪的值EN