NSMutableDictionary 排序问题
2024-09-29 13:00:41
NSMutableDictionary 默认情况下是按字母的顺序进行排序的 (a-z)的默认排序
如何自定义排序呢?
第一种,利用数组的sortedArrayUsingComparator调用 NSComparator ,obj1和obj2指的数组中的对象
示例:
//声明一个数组
NSArray *sortArray = [[NSArray alloc] initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"15",@"12",@"20",@"28",@"",nil];
//排序前输出
NSMutableString *outputBefore = [[NSMutableString alloc] init];
for(NSString *str in sortArray){
[outputBefore appendFormat:@"];
}
NSLog(@"排序前:%@",outputBefore); //调用sortedArrayUsingComparator排序后
NSArray *array = [sortArray sortedArrayUsingComparator:cmptr];
NSMutableString *outputAfter = [[NSMutableString alloc] init];
for(NSString *str in array){
[outputAfter appendFormat:@"%@",str];
}
NSLog(@"排序后:%@",outputAfter); //调用的排序的方法
NSComparator cmptr = ^(id obj1, id obj2){
if ([obj1 integerValue] > [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedDescending;
} if ([obj1 integerValue] < [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
};
第二种 排序方法 利用sortedArrayUsingFunction 调用 对应方法customSort,这个方法中的obj1和obj2分别是指数组中的对象。
NSArray *sortArray = [[NSArray alloc] initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"15",@"12",@"20",@"28",@"",nil];
//排序前
NSMutableString *outputBefore = [[NSMutableString alloc] init];
for(NSString *str in sortArray){
[outputBefore appendFormat:@"];
}
NSLog(@"排序前:%@",outputBefore); NSArray *array = [sortArray sortedArrayUsingFunction:customSort context:nil]; NSMutableString *outputAfter = [[NSMutableString alloc] init];
for(NSString *str in array){
[outputAfter appendFormat:@"];
}
NSLog(@"排序后:%@",outputAfter); NSInteger customSort(id obj1, id obj2,void* context){
if ([obj1 integerValue] > [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedDescending;
} if ([obj1 integerValue] < [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
}
第三种 利用sortUsingDescriptors调用NSSortDescriptor
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"price"
ascending:NO];//其中,price为数组中的对象的属性,这个针对数组中存放对象比较更简洁方便
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:&sortDescriptor count:1];
[_totalInfoArray sortUsingDescriptors:sortDescriptors];
[_airListView refreshTable:_totalInfoArray];
字符串的比较模式:
NSComparator cmptr = ^(id obj1, id obj2){
if([[NSString stringWithFormat:@"%@",obj1] compare:[NSString stringWithFormat:@"%@",obj2] options:NSNumericSearch] > 0)
{
return (NSComparisonResult)NSOrderedDescending;
} if([[NSString stringWithFormat:@"%@",obj1] compare:[NSString stringWithFormat:@"%@",obj2] options:NSNumericSearch] < 0)
{
return (NSComparisonResult)NSOrderedAscending;
} return (NSComparisonResult)NSOrderedSame;
};
数字比较模式:
NSInteger customSort(id obj1, id obj2,void* context){
if ([obj1 integerValue] > [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedDescending;
} if ([obj1 integerValue] < [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
}
本文来自:http://www.gowhich.com/blog/177
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