Question

ios开发中NSArray怎么用NSPredicate来过滤数组内容

Answer 1

//找出一个数组
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *defaultPath = [[NSBundle mainBundle] resourcePath];
NSError *error;

NSArray *directoryContents = [fileManager contentsOfDirectoryAtPath:defaultPath error:&error]
//匹配字符串，反回结果， SELF＝＝表示数组中每一个元素
NSString *match = @"imagexyz-999.png";
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF == %@", match];
NSArray *results = [directoryContents filteredArrayUsingPredicate:predicate];

//近似匹配字符串，类似SQL中的语法
NSString *match = @"imagexyz*.png";
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF like %@", match];
NSArray *results = [directoryContents filteredArrayUsingPredicate:predicate];
//不区分大小写匹配
NSString *match = @"imagexyz*.png";
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF like[cd] %@", match];
NSArray *results = [directoryContents filteredArrayUsingPredicate:predicate];
//正则匹配
NSString *match = @"imagexyz-//d{3}//.png";
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF matches %@", match];
NSArray *results = [directoryContents filteredArrayUsingPredicate:predicate];