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NSMutableDictionary 排序问题

2024-07-15 13:07:58   213人阅读

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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