ios学习:文件简单读写

2013.10.05补充  参考自 http://www.cnblogs.com/chinapcc/archive/2013/04/03/2673092.html

要把自定义类保存到plist文件里，要注意一下三点：

1、自定义类要继承NSCoding协议，实现 -(void)encodeWithCoder:(NSCoder *)coder 方法和  - (id) initWithCoder: (NSCoder *)coder方法

2、在写入plist文件时要对数据序列化然后写入：[NSKeyedArchiver archiveRootObject:array toFile:filename];array是要写入的数据，filename是plist文件路径

3、在读取plist文件数据时要对数据反序列化才能用：NSArray *arr = [NSKeyedUnarchiver unarchiveObjectWithFile: filename];

建议在有条件的情况下还是把数据放到 NSMutableArray / NSArray / NSMutableDictionary / NSDictionary 里，写入plist文件吧

 

ios项目的文件分工程项目里的文件和程序沙盒里的文件两种,其中项目工程里的文件是只读的,为沙盒里的文件可读可写.对于读文件而言,不管是工程里的还是沙盒的,方法都一样,唯一不同的在于文件路径的获取.

1 文件目录

 

2 txt文件.每一行数据的字段之间是用 \t 来分割

 

3  TWFXCityCode类:

 1 #import <Foundation/Foundation.h>
 2 
 3 @interface TWFXCityCode : NSObject
 4 {
 5    @public
 6     NSString *cityName;
 7     NSString *cityCode;
 8     NSString *pinyin;
 9     NSString *sortPinyin;
10     NSString *provinceName;
11     NSString *provinceCode;    
12 }
13 
14 @end

 

4 TWFXViewController类的头文件

 1 #import <UIKit/UIKit.h>
 2 #import "TWFXCityCode.h"
 3 
 4 @interface TWFXViewController : UIViewController
 5 
 6 @property (retain, nonatomic) NSMutableArray *weatherData;
 7 
 8 - (IBAction)btnClick_readFile:(UIButton *)sender;
 9 - (IBAction)btnClick_writePlist:(UIButton *)sender;
10 - (IBAction)btnClick_readPlist:(UIButton *)sender;
11 - (IBAction)btnClick_test:(UIButton *)sender;
12 @end

 

5 项目工程里txt文件的读取:

 1 NSString *filePath = [[NSBundle mainBundle] pathForResource:@"test123" ofType:@"txt"];
 2 
 3    NSArray *fileData;
 4     NSError *error;
 5 
 6     //读取file文件并把内容根据换行符分割后赋值给NSArray
 7     fileData = [[NSString stringWithContentsOfFile:filePath
 8                                           encoding:NSUTF8StringEncoding
 9                                              error:&error]
10                 componentsSeparatedByString:@"\n"];
11     
12     
13     //获取NSArray类型对象的迭代器
14     NSEnumerator *arrayEnumerator = [fileData objectEnumerator];
15     NSString *tempStr;
16     
17     while (tempStr = [arrayEnumerator nextObject]) {
18         
19         TWFXCityCode *cityCode = [[TWFXCityCode alloc] init];
20         
21         //把每行字符串再按 \t 符分割
22         NSArray *cityInfo = [tempStr componentsSeparatedByString:@"\t"];
23         
24         cityCode->cityCode = cityInfo[0];
25         cityCode->cityName = cityInfo[1];
26         cityCode->pinyin   = cityInfo[2];
27         cityCode->sortPinyin = cityInfo[3];
28         cityCode->provinceCode = cityInfo[4];
29         cityCode->provinceName = cityInfo[5];
30         
31         [self.weatherData addObject:cityCode];
32         [cityCode release];
33     }

 

6 把数据保存到沙盒里的plist文件

 1  //获取应用程序沙盒的Documents目录
 2     NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 3     
 4     NSString *plistPath1 = [paths objectAtIndex:0];
 5     
 6     //得到完整路径名
 7     NSString *filename = [plistPath1 stringByAppendingPathComponent:@"weathertest.plist"];
 8     
 9     //保存对字符串解析后的数据.dictionary里的value不能是自定类型对象么?还是说自定义类要实现指定的协议?
10     //没办法,暂时先用一个dictionary来保存value吧
11     NSMutableDictionary *myDic = [[NSMutableDictionary alloc] init];
12         
13     for (TWFXCityCode *city in self.weatherData) {
14             
15         NSMutableDictionary *tempDic = [[NSMutableDictionary alloc] init];
16         [tempDic setValue:city->cityCode forKey:@"cityID"];
17         [tempDic setValue:city->cityName forKey:@"cityName"];
18         [tempDic setValue:city->pinyin forKey:@"cityPinyin"];
19         [tempDic setValue:city->sortPinyin forKey:@"citySortPinyin"];
20         [tempDic setValue:city->provinceCode forKey:@"provinceID"];
21         [tempDic setValue:city->provinceName forKey:@"provinceName"];
22         
23         [myDic setValue:tempDic forKey:city->cityCode];
24     }
25     
26     NSLog(@"写plist文件完成");
27     [myDic writeToFile:filename atomically:YES];
28

 

7 沙盒里plist文件的内容

 

posted @ 2013-01-29 21:19  仙外仙  阅读(5178)  评论(0)  编辑  收藏  举报