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标题: objective-c - 无法将我的类(class)的 NSMutableArray 保存到文件(IOS) [打印本页]

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作者: 菜鸟教程小白    时间: 2022-12-12 19:44
标题: objective-c - 无法将我的类(class)的 NSMutableArray 保存到文件(IOS)

无法找出我的代码不起作用的原因。请帮助某人。

我创建了自己的类，实现了 NSCoding 协议(protocol)。不知道我错过了什么或错了什么。

这里是保存代码

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *fileName = [documentsDirectory stringByAppendingPathComponent"Currency.plist"]; 

Item * item = [[Item alloc] init];
item.x = 3; item.y = 5; item.type = (TType) 3; item.isSelected = NO;

NSMutableArray * array = [[NSMutableArray alloc] init];
[array addObject:item];

[array fileName atomically:YES]  // ( Doesn't Save the file ,returns NO);

这是我类(class)的代码 *.h*

#import <Foundation/Foundation.h> 

enum TType 
{
    kNone = 0, 
    KFirst = 1,
    ....
}; 

@interface Item : NSObject <NSCoding>{

}  

@property (nonatomic) int x;
@property (nonatomic) int y;
@property (nonatomic) enum TType type;
@property (nonatomic) BOOL isSelected;

@end

.m

@implementation Item
@synthesize x, y , type , isSelected;

#pragma mark NSCoding Protocol

- (void)encodeWithCoderNSCoder *)encoder;
{
  [encoder encodeInt32:[self x] forKey"x"];
  [encoder encodeInt32:[self y] forKey"y"];
  [encoder encodeInt32:[self type] forKey"type"];
  [encoder encodeBool:[self isSelected] forKey"isSelected"];
}

- (id)initWithCoderNSCoder *)decoder;
{
    if ( ![super init] )
        return nil;

    [self setX:[decoder decodeInt32ForKey"x"]];
    [self setY:[decoder decodeInt32ForKey"y"]];
    [self setTypeTType)[decoder decodeInt32ForKey"color"]];
    [self setIsSelected:[decoder decodeBoolForKey"isSelected"]];

    return self;
}

@end

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Best Answer-推荐答案

我想您会在以下位置找到答案:objects conforming to nscoding will not writetofile

即您不能将 Item 类序列化为属性列表，因为它不是属性列表对象(NSString、NSData、NSArray 或 NSDictionary)。

参见 writeToFile:atomically: 的文档:

This method recursively validates that all the contained objects are property list objects before writing out the file, and returns NO if all the objects are not property list objects, since the resultant file would not be a valid property list.

关于objective-c - 无法将我的类(class)的 NSMutableArray 保存到文件(IOS)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/9756861/

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