iphone - 使用NSScanner查找短语的下一个匹配项

Question

我正在使用以下代码在HTML文件中查找特定的代码行:

NSURL *requestTimetableURL = [NSURL URLWithString:@"http://www.dhsb.org/index.phtml?d=201435"];
NSLog(@"Loaded Timetable");
NSError *error;
NSString *page = [NSString stringWithContentsOfURL:requestTimetableURL 
                                              encoding:NSASCIIStringEncoding
                                                 error:&error];

[webView loadHTMLString:page baseURL:requestTimetableURL];

NSString* Period1;

NSScanner *htmlScanner =  [NSScanner scannerWithString:page];

[htmlScanner scanUpToString:@"<P align=center><STRONG><FONT color=#c00000>" intoString:NULL];
[htmlScanner scanString:@"<P align=center><STRONG><FONT color=#c00000>" intoString:NULL];
[htmlScanner scanUpToString:@"</FONT>" intoString:&Period1];

period1label.text= Period1;

NSLog(@"Collected Period 1 Data: %@", Period1);

NSScanner *htmlScanner2 =  [NSScanner scannerWithString:page];

NSString* Period2;

[htmlScanner2 scanUpToString:@"<P align=center><STRONG><FONT color=#c00000>" intoString:NULL];
[htmlScanner2 scanString:@"<P align=center><STRONG><FONT color=#c00000>" intoString:NULL];
[htmlScanner2 scanUpToString:@"</FONT>" intoString:&Period2];

period2label.text= Period2;

NSLog(@"Collected Period 2 Data: %@", Period2);

您会注意到，要查找的两个字符串是相同的。这是因为实际上没有什么可区分两行代码。有以下两个匹配项:

<P align=center><STRONG><FONT color=#c00000>

在我的代码中。如何在“Period1”上寻找第一场比赛，在“Period2”上寻找第二场比赛？

谢谢!

Answer 1

在使用第二台扫描仪之前，将scanLocation设置为该短语的第一个实例的开头之外，如下所示:
[htmlScanner2 setScanLocation:(htmlScanner1.scanLocation + 1)];
编辑:只是一个想法-为什么要使用两个扫描仪？像这样使用一台扫描仪:

NSURL *requestTimetableURL = [NSURL URLWithString:@"http://www.dhsb.org/index.phtml?d=201435"];
NSLog(@"Loaded Timetable");
NSError *error;
NSString *page = [NSString stringWithContentsOfURL:requestTimetableURL 
                                              encoding:NSASCIIStringEncoding
                                                 error:&error];

[webView loadHTMLString:page baseURL:requestTimetableURL];

NSString* Period1;

NSScanner *htmlScanner =  [NSScanner scannerWithString:page];

[htmlScanner scanUpToString:@"<P align=center><STRONG><FONT color=#c00000>" intoString:NULL];
[htmlScanner scanString:@"<P align=center><STRONG><FONT color=#c00000>" intoString:NULL];
[htmlScanner scanUpToString:@"</FONT>" intoString:&Period1];

period1label.text= Period1;

NSLog(@"Collected Period 1 Data: %@", Period1);

NSString* Period2;

[htmlScanner scanUpToString:@"<P align=center><STRONG><FONT color=#c00000>" intoString:NULL];
[htmlScanner scanString:@"<P align=center><STRONG><FONT color=#c00000>" intoString:NULL];
[htmlScanner scanUpToString:@"</FONT>" intoString:&Period2];

period2label.text= Period2;

NSLog(@"Collected Period 2 Data: %@", Period2);