string StreamReader 的行到字符串数组
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Lines of a StreamReader to an array of string
提问by whoone
I want to get a string[]assigned with a StreamReader. Like:
我想获得一个string[]带有StreamReader. 喜欢：
try{
StreamReader sr = new StreamReader("a.txt");
do{
str[i] = sr.ReadLine();
i++;
}while(i < 78);
}
catch (Exception ex){
MessageBox.Show(ex.ToString());
}
I can do it but can't use the string[]. I want to do this:
我可以做到，但不能使用字符串[]。我想做这个：
MessageBox.Show(str[4]);
If you need further information feel free to ask, I will update. thanks in advance...
如果您需要更多信息，请随时询问，我会更新。提前致谢...
回答by C???
If you really want a string array, I would approach this slightly differently. Assuming you have no idea how many lines are going to be in your file (I'm ignoring your hard-coded value of 78 lines), you can't create a string[]of the correct size up front.
如果你真的想要一个字符串数组，我会稍微不同地处理这个。假设您不知道文件中有多少行（我忽略了 78 行的硬编码值），您无法预先创建string[]正确大小的 。
Instead, you could start with a collection of strings:
相反，您可以从一组字符串开始：
var list = new List<string>();
Change your loop to:
将您的循环更改为：
using (var sr = new StreamReader("a.txt"))
{
string line;
while ((line = sr.ReadLine()) != null)
{
list.Add(line);
}
}
And then ask for a string array from your list:
然后从您的列表中请求一个字符串数组：
string[] result = list.ToArray();
Update
更新
Inspired by Cuong's answer, you can definitely shorten this up. I had forgotten about this gem on the Fileclass:
受Cuong 回答的启发，您绝对可以缩短此时间。我已经忘记了File课堂上的这颗宝石：
string[] result = File.ReadAllLines("a.txt");
What File.ReadAllLinesdoes under the hood is actually identical to the code I provided above, except Microsoft uses an ArrayListinstead of a List<string>, and at the end they return a string[]array via return (string[]) list.ToArray(typeof(string));.
什么File.ReadAllLines引擎盖下做实际上是相同的我上面提供的码，除了Microsoft使用的ArrayList，而不是一个List<string>，并且在结束时，他们返回一个string[]通孔阵列return (string[]) list.ToArray(typeof(string));。
