iphone - 如何将 NSArray 数据分配给 iPhone 中的 NSMutableArray？

Question

在我的应用程序中，我有一个包含一些数据的 NSArray。我想获取该数据并将其放入被NSMutableArray调用的subArrayData. 我能够将我的第一个数组中的数据插入到可变数组中，但是当应用程序运行时，我得到：

警告：从“nsarray *”分配给“nsmutablearray *”的不兼容指针类型请帮忙。

以下是我的代码：.h 文件

#import <UIKit/UIKit.h>

@interface AddNew : UIViewController
{
    NSMutableArray *subArrayData;;
}
@property(nonatomic ,retain)NSMutableArray *subArrayData;

.m 文件

#import "AddNew.h"
#import "DashBoardPage.h"
#import "SubmitYourListing.h"


@implementation AddNew

@synthesize subArrayData;

-(void)accommodationAndTravel
{
    subArrayData =[[NSArray alloc] initWithArray:[NSArray arrayWithObjects:@"Select one",@"Accommodation and travel hospitality",@"Apartments and villas",@"Bed and Breakfast",@"Caravan parks and campsites",@"Hospitality",
                                                  @"Hotels and Motels",@"Snow and Ski lodges",@"Tourist attractions and tourism information",@"Tours and Holidays",@"Travel agents and Services",nil]];


}

Answer 1

您可以通过调用 -mutableCopy 方法将任何 NSArray 转换为 NSMutable 数组：

NSArray *someArray = ...;
NSMutableArray* subArrayData = [someArray mutableCopy];

Answer 2

更改 .m 文件

#import "AddNew.h"
#import "DashBoardPage.h"
#import "SubmitYourListing.h"


@implementation AddNew

@synthesize subArrayData;

-(void)accommodationAndTravel
{
    subArrayData =[[NSMutableArray alloc] initWithArray:[NSArray arrayWithObjects:@"Select one",@"Accommodation and travel hospitality",@"Apartments and villas",@"Bed and Breakfast",@"Caravan parks and campsites",@"Hospitality",
                                                  @"Hotels and Motels",@"Snow and Ski lodges",@"Tourist attractions and tourism information",@"Tours and Holidays",@"Travel agents and Services",nil]];


}

Answer 3

只需调用NSMutableArray's 的初始化程序之一，如下所示：

subArrayData = [[NSMutableArray alloc] initWithObjects:
                                        @"Select one",
                                        @"Accommodation and travel hospitality",
                                        @"Apartments and villas",
                                        @"Bed and Breakfast",
                                        @"Caravan parks and campsites",
                                        @"Hospitality",
                                        @"Hotels and Motels",
                                        @"Snow and Ski lodges",
                                        @"Tourist attractions and tourism information",
                                        @"Tours and Holidays",
                                        @"Travel agents and Services",
                                        nil]];

对于处理现有 的情况NSArray，您可以进行mutableCopy：

- (id)initWithArray:(NSArray *)array
{
  self = [super init];
  if (nil != self) {
    subArrayData = [array mutableCopy];
    ...