Question

更新

我不想使用XML解析器，因为这是所有字符串。非常小，所以，请不要解析器。感谢。

我有一个像这样的XML字符串：<AppVersion>5</AppVersion>。现在我想得到5。怎么办？

请注意，5也可以是50。我的意思是长度会改变。

Answer 1

您可以使用正则表达式：

NSString *string = @"<AppVersion>50</AppVersion>";
NSError *error;

// this looks for any sequence of digits between 0 and 9 between those two tags

NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"<AppVersion>([0-9]+)</AppVersion>"
                                                                       options:NSRegularExpressionCaseInsensitive
                                                                         error:&error];
if (error)
    NSLog(@"%s: regularExpressionWithPattern error: %@", __FUNCTION__, error);

NSTextCheckingResult *match = [regex firstMatchInString:string options:0 range:NSMakeRange(0, [string length])];
NSRange range = [match rangeAtIndex:1];
if (range.location != NSNotFound)
{
    NSString *result = [string substringWithRange:range];
    NSLog(@"%@", result);
}

或者您可以使用扫描仪：

NSScanner *scanner = [NSScanner scannerWithString:string];
[scanner scanUpToCharactersFromSet:[NSCharacterSet decimalDigitCharacterSet] intoString:nil];
NSInteger i;
if ([scanner scanInteger:&i])
    NSLog(@"%d", i);

Answer 2

我假设你有字符串并且正在寻找一种简单的方法来提取数字。这可以通过几行代码完成。我们知道起点，因为它是一个常数。结束点可能因数字的长度而异。



NSString *xml=@"<AppVersion>5</AppVersion>";
int start=12; // Constant
NSRange end = [xml rangeOfString:@"</"]; // Depends on length

NSString *aNum = [xml substringWithRange:NSMakeRange(start, end.location-start)];
NSLog(@"%@", aNum);

NSString *xml=@"<AppVersion>5</AppVersion>"; int start=12; // Constant NSRange end = [xml rangeOfString:@"</"]; // Depends on length NSString *aNum = [xml substringWithRange:NSMakeRange(start, end.location-start)]; NSLog(@"%@", aNum);

三个例子表明它适用于一般情况：

// Test 5
NSString *xml=@"<AppVersion>5</AppVersion>";
int start=12; // Constant
NSRange end = [xml rangeOfString:@"</"]; // Depends on length

NSString *aNum = [xml substringWithRange:NSMakeRange(start, end.location-start)];
NSLog(@"%@", aNum);

// Test 500
xml=@"<AppVersion>500</AppVersion>";
end = [xml rangeOfString:@"</"]; // Depends on length

aNum = [xml substringWithRange:NSMakeRange(start, end.location-start)];
NSLog(@"%@", aNum);

// Test 500000
xml=@"<AppVersion>500000</AppVersion>";
end = [xml rangeOfString:@"</"]; // Depends on length

aNum = [xml substringWithRange:NSMakeRange(start, end.location-start)];
NSLog(@"%@", aNum);

Answer 3

我有自己的类别来从XML获取价值但您可以尝试使用NSXMLParser

如何从NSString获取int？

3 个答案: