这是一个非常漫长的方法，它试图将其删除有点混乱，所以StackOverflow允许我发布这么多。
StatsViewController prepareForSegue方法：
` - （void）prepareForSegue：（UIStoryboardSegue *）segue sender：（id）sender { // stat1 data ... COMPLETE if（[segue.identifier isEqualToString：@“stat1Seg”]）{
CiteViewController *citeScreen = [segue destinationViewController];
citeScreen.citeWhichStat = @"1";
if ([statWhichTopic isEqualToString:@"abortion"]) {
citeScreen.strMLA = @"Mantel, Barbara. \"Abortion.\" CQ Researcher 19 May 2015. Web. 4 Mar. 2016.";
citeScreen.strAPA = @"Mantel, B. (2015, May 19). Abortion. CQ Researcher. Retrieved from http://library.cqpress.com.ezaccess.libraries.psu.edu/";
citeScreen.citeWhichTopic = @"abortion";
}
else if ([statWhichTopic isEqualToString:@"agriculture"]) {
citeScreen.strMLA = @"\"Nitrogen.\" CropNutrition.com. The Mosaic Company, 2013. Web. 30 Apr. 2016.";
citeScreen.strAPA = @"CropNutrition.com. (2013). Nitrogen. Retrieved April 30, 2016, from http://www.cropnutrition.com/efu-nitrogen#overview";
citeScreen.citeWhichTopic = @"agriculture";
}
else if ([statWhichTopic isEqualToString:@"climateChange"]) {
citeScreen.strMLA = @"\"Causes of Climate Change.\" EPA: United States Environmental Protection Agency, 23 Feb. 2016. Web. 12 Apr. 2016.";
citeScreen.strAPA = @"EPA. (2016, February 23). Causes of Climate Change. Retrieved April 12, 2016, from https://www3.epa.gov/climatechange/science/causes.html";
citeScreen.citeWhichTopic = @"climateChange";
}
else if ([statWhichTopic isEqualToString:@"cybersecurity"]) {
citeScreen.strMLA = @"\"Top Cybersecurity Statistics for 2016 - Cyber Security Marketing Blog.\" Cyber Security Marketing Blog. Penguin Strategies, 17 Jan. 2016. Web. 16 Apr. 2016.";
citeScreen.strAPA = @"Penguin Strategies. (2016, January 17). Top Cybersecurity Statistics for 2016 - Cyber Security Marketing Blog. Retrieved April 16, 2016, from http://www.marketingcybersecurity.com/2016-cybersecurity-statistics/";
citeScreen.citeWhichTopic = @"cybersecurity";
}
else if ([statWhichTopic isEqualToString:@"discrimination"]) {
citeScreen.strMLA = @"Logan, John R. \"Separate and Unequal: The Neighborhood Gap for Blacks, Hispanics and Asians in Metropolitan America.\" (n.d.): n. pag. Report0727. US2010: Discover America in a New Century, July 2011. Web. 22 Apr. 2016.";
citeScreen.strAPA = @"Logan, J. R. (2011, July). Separate and Unequal: The Neighborhood Gap for Blacks, Hispanics and Asians in Metropolitan America. Retrieved April 22, 2016, from http://www.s4.brown.edu/us2010/Data/Report/report0727.pdf";
citeScreen.citeWhichTopic = @"discrimination";
}
else if ([statWhichTopic isEqualToString:@"education"]) {
citeScreen.strMLA = @"\"Fast Facts- Career and Technical Education.\" National Center for Education Statistics. U.S. Department of Education, Institute of Education Sciences, n.d. Web. 27 Apr. 2016.";
citeScreen.strAPA = @"National Center for Education Statistics. (n.d.). Fast Facts- Career and technical education. Retrieved April 27, 2016, from https://nces.ed.gov/fastfacts/display.asp?id=43";
citeScreen.citeWhichTopic = @"education";
}
else if ([statWhichTopic isEqualToString:@"energy"]) {
citeScreen.strMLA = @"\"India's Crude Oil Imports Rose 7% in 2015-16 as Consumption Grew by 11%.\"Enerdata. Enerdata, 22 Apr. 2016. Web. 29 Apr. 2016.";
citeScreen.strAPA = @"Enerdata. (2016, April 22). India's crude oil imports rose 7% in 2015-16 as consumption grew by 11%. Retrieved April 29, 2016, from http://www.enerdata.net/enerdatauk/press-and-publication/energy-news-001/indias-crude-oil-imports-rose-7-2015-16-consumption-grew-11_36906.html";
citeScreen.citeWhichTopic = @"energy";
}
else if ([statWhichTopic isEqualToString:@"gunControl"]) {
citeScreen.strMLA = @"Fingerhut, Hannah. \"5 Facts about Guns in the United States.\" Pew Research Center- Fact Tank: News in the Numbers. Pew Research Center, 05 Jan. 2016. Web. 28 Apr. 2016.";
citeScreen.strAPA = @"Fingerhut, H. (2016, January 05). 5 facts about guns in the United States. Retrieved April 28, 2016, from http://www.pewresearch.org/fact-tank/2016/01/05/5-facts-about-guns-in-the-united-states/";
citeScreen.citeWhichTopic = @"gunControl";
}
else if ([statWhichTopic isEqualToString:@"internet"]) {
citeScreen.strMLA = @"\"Internet Live Stats - Internet Usage & Social Media Statistics.\" Internet Live Stats - Internet Usage & Social Media Statistics. InternetLiveStats.com, n.d. Web. 21 Apr. 2016.";
citeScreen.strAPA = @"InternetLiveStats.com. (n.d.). Internet Live Stats - Internet Usage & Social Media Statistics. Retrieved April 21, 2016, from http://www.internetlivestats.com/";
citeScreen.citeWhichTopic = @"internet";
}
else if ([statWhichTopic isEqualToString:@"marijuana"]) {
citeScreen.strMLA = @"\"Marijuana Stats.\" Caron. Caron Treatment Centers, 2016. Web. 30 Apr. 2016.";
citeScreen.strAPA = @"Caron Treatment Centers. (2016). Marijuana Stats. Retrieved April 30, 2016, from http://www.caron.org/understanding-addiction/statistics-outcomes/marijuana-stats";
citeScreen.citeWhichTopic = @"marijuana";
}
else if ([statWhichTopic isEqualToString:@"overpopulation"]) {
citeScreen.strMLA = @"Hetzel, Lisa, and Annetta Smith. \"65 Years and Over Population: 2001.\" Google Books. Diane Publish Co., 2008. Web. 10 Apr. 2016.";
citeScreen.strAPA = @"Hetzel, L., & Smith, A. (2008). 65 Years and Over Population: 2001. Retrieved April 10, 2016, from https://books.google.com/books?id=Gndl_pIhnZkC";
citeScreen.citeWhichTopic = @"overpopulation";
}
else if ([statWhichTopic isEqualToString:@"police"]) {
citeScreen.strMLA = @"USA.gov. \"Uniform Crime Reports- Detailed Assault Data.\" FBI- The Federal Bureau of Investigation. U.S. Government, U.S. Department of Justice, 2014. Web. 29 Apr. 2016.";
citeScreen.strAPA = @"FBI. (2014). Uniform Crime Reports- Detailed Assault Data. Retrieved April 29, 2016, from https://www.fbi.gov/about-us/cjis/ucr/leoka/2014/detailed-assault-topic-page-summaries";
citeScreen.citeWhichTopic = @"police";
}
else if ([statWhichTopic isEqualToString:@"pornography"]) {
citeScreen.strMLA = @"\"Pornhub’s 2015 Year in Review.\" Pornhub Insights. Pornhub, 2016. Web. 19 Apr. 2016.";
citeScreen.strAPA = @"\"Pornhub’s 2015 Year in Review.\" Pornhub Insights. Pornhub, 2016. Web. 19 Apr. 2016.";
citeScreen.citeWhichTopic = @"pornography";
}
else if ([statWhichTopic isEqualToString:@"prison"]) {
citeScreen.strMLA = @"Savage, Charlie. \"Justice Dept. Seeks to Curtail Stiff Drug Sentences.\" The New York Times. The New York Times, 11 Aug. 2013. Web. 20 Apr. 2016.";
citeScreen.strAPA = @"Savage, C. (2013). Justice Dept. Seeks to Curtail Stiff Drug Sentences. Retrieved April 20, 2016, from http://www.nytimes.com/2013/08/12/us/justice-dept-seeks-to-curtail-stiff-drug-sentences.html?pagewanted=all";
citeScreen.citeWhichTopic = @"prison";
}
else if ([statWhichTopic isEqualToString:@"rape"]) {
citeScreen.strMLA = @"\"Facts & Quotes: Statistics.\" Rape Treatment Center | Santa Monica | UCLA Medical Center. Rape Treatment Center, n.d. Web. 18 Apr. 2016.";
citeScreen.strAPA = @"Rape Treatment Center. (n.d.). Facts & Quotes: Statistics. Retrieved April 18, 2016, from http://www.911rape.org/facts-quotes/statistics";
citeScreen.citeWhichTopic = @"rape";
}
else if ([statWhichTopic isEqualToString:@"religion"]) {
citeScreen.strMLA = @"\"The Global Religious Landscape.\" Pew Research Center- Religion Public Life. Pew Research Center, 18 Dec. 2012. Web. 29 Apr. 2016.";
citeScreen.strAPA = @"Pew Research Center. (2012, December 18). The Global Religious Landscape. Retrieved April 29, 2016, from http://www.pewforum.org/2012/12/18/global-religious-landscape-exec/";
citeScreen.citeWhichTopic = @"religion";
}
else if ([statWhichTopic isEqualToString:@"robotics"]) {
citeScreen.strMLA = @"\"Industrial Robot Statistics.\" Statistics- IFR International Federation of Robotics. IFR, 2015. Web. 26 Apr. 2016.";
citeScreen.strAPA = @"IFR- International Federation of Robotics. (2015). Industrial Robot Statistics. Retrieved April 26, 2016, from http://www.ifr.org/industrial-robots/statistics/";
citeScreen.citeWhichTopic = @"robotics";
}
else if ([statWhichTopic isEqualToString:@"socialMedia"]) {
citeScreen.strMLA = @"Baer, Jay. \"11 Shocking New Social Media Statistics in America.\" Convince & Convert. Convince & Convert, LLC, 2008-2016. Web. 27 Apr. 2016.";
citeScreen.strAPA = @"Baer, J. (2008-2016). 11 Shocking New Social Media Statistics in America. Retrieved April 27, 2016, from http://www.convinceandconvert.com/social-media-research/11-shocking-new-social-media-statistics-in-america/";
citeScreen.citeWhichTopic = @"socialMedia";
}
else if ([statWhichTopic isEqualToString:@"sexuality"]) {
citeScreen.strMLA = @"\"FAQ: Facts and Statistics.\" The Kinsey Institute - Sexuality Information Links - FAQ [Related Resources]. The Kinsey Institute/ Indiana University, 1996-2016. Web. 21 Apr. 2016.";
citeScreen.strAPA = @"The Kinsey Institute/ Indiana University. (1996-2016). The Kinsey Institute - Sexuality Information Links - FAQ [Related Resources]. Retrieved April 21, 2016, from http://www.kinseyinstitute.org/resources/FAQ.html#resources";
citeScreen.citeWhichTopic = @"sexuality";
}
else {
citeScreen.strMLA = @"\"Falcon Heavy.\" SpaceX. Space Exploration Technologies Corp., 2016. Web. 26 Apr. 2016.";
citeScreen.strAPA = @"Space Exploration Technologies Corp. (2016). Falcon Heavy. Retrieved April 26, 2016, from http://www.spacex.com/falcon-heavy";
citeScreen.citeWhichTopic = @"spaceExploration";
}
}
else if ([statWhichTopic isEqualToString:@"religion"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"religion";
}
else if ([statWhichTopic isEqualToString:@"robotics"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"robotics";
}
else if ([statWhichTopic isEqualToString:@"socialMedia"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"socialMedia";
}
else if ([statWhichTopic isEqualToString:@"sexuality"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"sexuality";
}
else {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"spaceExploration";
}
}
//stat8 data... COMPLETE
else {
CiteViewController *citeScreen = [segue destinationViewController];
citeScreen.citeWhichStat = @"8";
if ([statWhichTopic isEqualToString:@"abortion"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"abortion";
}
else if ([statWhichTopic isEqualToString:@"agriculture"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"agriculture";
}
else if ([statWhichTopic isEqualToString:@"climateChange"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"climateChange";
}
else if ([statWhichTopic isEqualToString:@"cybersecurity"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"cybersecurity";
}
else if ([statWhichTopic isEqualToString:@"discrimination"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"discrimination";
}
else if ([statWhichTopic isEqualToString:@"education"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"education";
}
else if ([statWhichTopic isEqualToString:@"energy"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"energy";
}
else if ([statWhichTopic isEqualToString:@"gunControl"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"gunControl";
}
else if ([statWhichTopic isEqualToString:@"internet"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"internet";
}
else if ([statWhichTopic isEqualToString:@"marijuana"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"marijuana";
}
else if ([statWhichTopic isEqualToString:@"overpopulation"]) {
citeScreen.strMLA = @"Stancheva, Tina. \"Human Nature, Technology & the Environment.\" Human Nature, Technology & the Environment. 2003. Web. 10 Apr. 2016.";
citeScreen.strAPA = @"Stancheva, T. (2003). Human Nature, Technology & the Environment. Retrieved April 10, 2016, from http://fubini.swarthmore.edu/~ENVS2/S2003/Tina/overpopulation";
citeScreen.citeWhichTopic = @"overpopulation";
}
else if ([statWhichTopic isEqualToString:@"police"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"police";
}
else if ([statWhichTopic isEqualToString:@"pornography"]) {
citeScreen.strMLA = @"\"Pornhub’s 2015 Year in Review.\" Pornhub Insights. Pornhub, 2016. Web. 19 Apr. 2016.";
citeScreen.strAPA = @"\"Pornhub’s 2015 Year in Review.\" Pornhub Insights. Pornhub, 2016. Web. 19 Apr. 2016.";
citeScreen.citeWhichTopic = @"pornography";
}
else if ([statWhichTopic isEqualToString:@"prison"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"prison";
}
else if ([statWhichTopic isEqualToString:@"rape"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"rape";
}
else if ([statWhichTopic isEqualToString:@"religion"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"religion";
}
else if ([statWhichTopic isEqualToString:@"robotics"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"robotics";
}
else if ([statWhichTopic isEqualToString:@"socialMedia"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"socialMedia";
}
else if ([statWhichTopic isEqualToString:@"sexuality"]) {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"sexuality";
}
else {
citeScreen.strMLA = @"";
citeScreen.strAPA = @"";
citeScreen.citeWhichTopic = @"spaceExploration";
}
}
} `
答案 0 :(得分：0)
if语句不能'保留'else语句中的数据。它只是意味着if语句中的条件没有得到满足，因此它是默认的。我建议你检查segue标识符的拼写。代码中的代码必须与故事板完全匹配。除了堕胎统计数据之外，如果所有其他人都能工作，这是我唯一能想到的。如果这不起作用，请尝试添加一些NSLog语句来打印segue标识符，看看为什么它不等于“abortSeg”。
关于你的第二个问题，我并不完全明白你在问什么。从导航堆栈弹出视图控制器时，您的应用程序崩溃了？我需要看一些代码来弄清楚出了什么问题。