在我的应用程序中,我有一个带有50k +联系人的db。要在列表视图中显示它们,我需要计算索引节标题以在右侧显示它们。根据联系人姓名获取sectionIndex标题
然而,我的逻辑花费大约3-6秒的时间来准备数据源。
-(NSArray *)getSectionTitleBasedOn:(NSString*)sortBy{
for (RealmContact *contact in contactSource){
if (contact.firstName.length>0) {
if ([sortBy isEqualToString:@"FirstName"]) {
NSString *firName= [contact.firstName stringByReplacingOccurrencesOfString:@" " withString:@""];
NSString *regex = @"^[A-Za-z]+";
NSPredicate *test = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
BOOL result = [test evaluateWithObject:firName];
if (contact.firstName.length>0 && result)
{
[nameDic setObject:@"firstletter" forKey:[[contact.firstName substringToIndex:1]uppercaseString]];
}else{
[nameDic setObject:@"firstletter" forKey:@"#"];
}
}
if ([sortBy isEqualToString:@"LastName"]) {
//same
}
if ([sortBy isEqualToString:@"Company"]) {
//same
}
}
}
NSLog(@"dic %@",nameDic);
return [[nameDic allKeys]sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];
}
我想知道是否有什么我可以做,以改善这一点。
NSString *firName= [contact.firstName stringByReplacingOccurrencesOfString:@" " withString:@""];
NSString *regex = @"^[A-Za-z]+";
NSPredicate *test = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
BOOL result = [test evaluateWithObject:firName];
我这样做来检查字符串是否包含特殊字符或无效字符。我得到数组后,我排序并返回数组。输出将是:
dic {
"#" = firstletter;
A = firstletter;
B = firstletter;
C = firstletter;
D = firstletter;
E = firstletter;
F = firstletter;
G = firstletter;
H = firstletter;
I = firstletter;
J = firstletter;
K = firstletter;
L = firstletter;
M = firstletter;
N = firstletter;
O = firstletter;
P = firstletter;
Q = firstletter;
R = firstletter;
S = firstletter;
T = firstletter;
U = firstletter;
V = firstletter;
W = firstletter;
X = firstletter;
Y = firstletter;
Z = firstletter;
}
我这样做的:https://pastebin.com/ixHsPSxh测试OSX模拟器,似乎更快(x10,但没有做更多的测试)。另外,你的代码的小错误:'if(contact.firstName.length> 0 && result)'和'[nameDic setObject:@“firstletter”forKey:[[contact.firstName substringToIndex:1] uppercaseString]];'应该使用'firName'而不是'contact.firstName'。 – Larme