-(NSString*) convertToDateString:(NSString*)str{
static NSDateFormatter *InDateFormatter = nil;
static NSDateFormatter *OutDateFormatter = nil;
NSString *outDate = nil;
if([str isKindOfClass:[NSString class]] && [str length] > 0){
NSString *dateStr = [[NSString alloc] initWithString:str];
if (InDateFormatter == nil) {
InDateFormatter = [[NSDateFormatter alloc] init];
InDateFormatter.dateFormat = @"yyyy-MM-dd";
}
if (OutDateFormatter == nil) {
OutDateFormatter = [[NSDateFormatter alloc] init];
OutDateFormatter.dateFormat = @"MM/dd/yy";
}
NSRange rangeOfDash = [dateStr rangeOfString:@"T"];
dateStr = (rangeOfDash.location != NSNotFound) ? [dateStr substringToIndex:rangeOfDash.location] : dateStr;
if([dateStr isKindOfClass:[NSString class]] && [dateStr length] == 10){
NSDate* date = [InDateFormatter dateFromString:dateStr];
if (date != nil) {
outDate = [OutDateFormatter stringFromDate:date];
}
}
}
return outDate;
}
行中发生崩溃" InDateFormatter.dateFormat = @" yyyy-MM-dd&#34 ;; 将有多个并行创建的类实例并调用上述方法。崩溃很少可以重现。
我没有正确使用日期格式化程序吗?提前致谢
答案 0 :(得分:4)
对于线程安全的延迟初始化,您可以使用GCD dispatch_once()
功能:
static NSDateFormatter *inDateFormatter;
static NSDateFormatter *outDateFormatter;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
inDateFormatter = [[NSDateFormatter alloc] init];
inDateFormatter.dateFormat = @"yyyy-MM-dd";
outDateFormatter = [[NSDateFormatter alloc] init];
outDateFormatter.dateFormat = @"MM/dd/yy";
});