我有一个 plist，我从我的包中读取到一个新的 plist 对象，我将它放在根目录中以进行读写。我的问题是我该怎么做，或者应用程序在退出时会做什么，更好的是，当应用程序从 ios 的“多任务”菜单中被杀死时会发生什么。
还有一种方法可以将此 plist 保存到内存/捆绑包以供将来再次使用应用程序时使用。
我的代码如下供参考。
这是我的.h
#import <Foundation/Foundation.h>
@interface EngineProperties : NSObject {
NSString *signature;
NSNumber *version;
NSNumber *request;
NSNumber *dataVersion;
NSMutableDictionary *cacheValue;
//cachevalue Items
NSNumber *man;
NSNumber *mod;
NSNumber *sub;
}
@property (copy, nonatomic) NSString *signature;
@property (copy, nonatomic) NSNumber *version;
@property (copy, nonatomic) NSNumber *request;
@property (copy, nonatomic) NSNumber *dataVersion;
@property (copy, nonatomic) NSMutableDictionary *cacheValue;
//cachevalue Items
@property (copy, nonatomic) NSNumber *man;
@property (copy, nonatomic) NSNumber *mod;
@property (copy, nonatomic) NSNumber *sub;
//Singletton
+ (id)sharedManager;
- (void) saveData:(NSString *)methodName signature:(NSString *)pSignature Version:(NSNumber *)pVersion request:(NSNumber *)rNumber dataVersion:(NSNumber *)dvReturned cacheValue:(NSNumber *)cValue;
@end
这是我的 .m
#import "EngineProperties.h"
static EnginePropertiesController *sharedMyManager = nil;
@implementation EngineProperties
@synthesize signature;
@synthesize version;
@synthesize request;
@synthesize dataVersion;
@synthesize cacheValue;
@synthesize man;
@synthesize mod;
@synthesize sub;
#pragma mark Singleton Methods
+ (id)sharedManager {
@synchronized(self) {
if (sharedMyManager == nil)
sharedMyManager = [[self alloc] init];
}
return sharedMyManager;
}
- (id)init {
if (self = [super init]) {
// Data.plist code
// get paths from root direcory
NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
// get documents path
NSString *documentsPath = [paths objectAtIndex:0];
// get the path to our Data/plist file
NSString *plistPath = [documentsPath stringByAppendingPathComponent:@"EngineProperties.plist"];
// check to see if Data.plist exists in documents
if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath])
{
// if not in documents, get property list from main bundle
plistPath = [[NSBundle mainBundle] pathForResource:@"EngineProperties" ofType:@"plist"];
}
// read property list into memory as an NSData object
NSData *plistXML = [[NSFileManager defaultManager] contentsAtPath:plistPath];
NSString *errorDesc = nil;
NSPropertyListFormat format;
// convert static property liost into dictionary object
NSDictionary *tempRoot = (NSMutableDictionary *)[NSPropertyListSerialization propertyListFromData:plistXML mutabilityOption:NSPropertyListMutableContainersAndLeaves format:&format errorDescription:&errorDesc];
if (!tempRoot)
{
NSLog(@"Error reading plist: %@, format: %d", errorDesc, format);
}
// assign values
self.signature = [tempRoot objectForKey:@"Signature"];
self.version = [tempRoot objectForKey:@"Version"];
self.request = [tempRoot objectForKey:@"Request"];
self.dataVersion = [tempRoot objectForKey:@"Data Version"];
man = [cacheValue objectForKey:@"Man"];
mod = [cacheValue objectForKey:@"Mod"];
sub = [cacheValue objectForKey:@"SubMod"];
cacheValue = [tempRoot objectForKey:@"Cache Value"];
}
- (void) saveData:(NSString *)methodName signature:(NSString *)pSignature Version:(NSNumber *)pVersion request:(NSNumber *)rNumber dataVersion:(NSNumber *)dvReturned cacheValue:(NSNumber *)cValue;
{
// get paths from root direcory
NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
// get documents path
NSString *documentsPath = [paths objectAtIndex:0];
// get the path to our Data/plist file
NSString *plistPath = [documentsPath stringByAppendingPathComponent:@"EngineProperties.plist"];
// set the variables to the values in the text fields
self.signature = pSignature;
self.version = pVersion;
self.request = rNumber;
self.dataVersion = dvReturned;
//do some if statment stuff here to put the cache in the right place or what have you.
if (methodName == @"manufacturers")
{
self.man = cValue;
}
else if (methodName == @"models")
{
self.mod = cValue;
}
else if (methodName == @"subMod")
{
self.sub = cValue;
}
self.cacheValue = [NSDictionary dictionaryWithObjectsAndKeys:
man, @"Manufacturers",
mod, @"Models",
sub, @"SubModels", nil];
NSDictionary *plistDict = [NSDictionary dictionaryWithObjectsAndKeys:
signature, @"Signature",
version, @"Version",
request, @"Request",
dataVersion, @"Data Version",
cacheValue, @"Cache Value", nil];
NSString *error = nil;
// create NSData from dictionary
NSData *plistData = [NSPropertyListSerialization dataFromPropertyList:plistDict format:NSPropertyListXMLFormat_v1_0 errorDescription:&error];
// check is plistData exists
if(plistData)
{
// write plistData to our Data.plist file
[plistData writeToFile:plistPath atomically:YES];
NSString *myString = [[NSString alloc] initWithData:plistData encoding:NSUTF8StringEncoding];
// NSLog(@"%@", myString);
}
else
{
NSLog(@"Error in saveData: %@", error);
// [error release];
}
}
@end