IOS文件的简单读写实例详解

 #pragma mark---NSString的写入与读取---  //1:获取路径  NSString *docunments = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)firstObject];  //2:在该路径下创建文件夹,文件夹名为字符串.txt  docunments = [docunments stringByAppendingString:@"/字符串.txt"];  //  NSLog(@"%@",docunments);  //3:编写文本内容  NSString *str = @"大家一起来";  //4:将文本写入到"字符串.txt"中  /*   writeToFile:文件路径,在这里是documents atomically:YES(若为YES,则保证了文件的原子性,即先创建一个临时文件,直到文件内容写入成功再导入目标文件(字符串.txt),为NO,直接写入目标文件里) encoding:编码格式是个枚举值 error:错误信息,一般为nil   */  BOOL result = [str writeToFile:docunments atomically:YES encoding:NSUTF8StringEncoding error:nil];  if (result) {    NSLog(@"我成功了");  }else{    NSLog(@"为啥失败了");  }  //读取  /*   stringWithContentsOfFile:路径 encoding:编码 error:nil,错误信息   */  NSString *newStr = [NSString stringWithContentsOfFile:docunments encoding:4 error:nil];  NSLog(@">>>>%@",newStr);  /*   .plist全名是：Property List，属性列表文件，它是一种用来存储串行化(当程序彻底退出后,对象就会随之消亡,但是,我们希望有些东西需要记录下来,以便于恢复,也可提升用户体验,而记录的这个过程,就叫串行化)后的对象的文件。属性列表文件的扩展名为.plist ，因此通常被称为 plist文件。文件是xml格式的。   注意:plist文件通常用于存储用户设置,也可用于存储捆绑信息   */#pragma mark---NSArray的写入与读取//获取路径  NSString *arrayDoc = [SandBox getDocuments];  //在arrayDoc下拼接文件名  NSString *arrPath = [arrayDoc stringByAppendingString:@"array.plist"];  //向数组中写入数据  NSArray *array = @[@"25",@"55",@"05",@"5885"];  //将数组写入文件  [array writeToFile:arrPath atomically:YES];  NSLog(@"数组存入路径%@",arrPath);  //读取  NSArray *newArray = [NSArray arrayWithContentsOfFile:arrPath];  NSLog(@"读取的文件:%@",newArray);#pragma mark--- 字典的写入与读取----  NSString *dicionaryDic = [SandBox getDocuments];  NSString *dicpath = [dicionaryDic stringByAppendingString:@"dictionary.plist"];  NSDictionary *dictionary = @{@"name":@"甲甲",@"age":@"18"};  [dictionary writeToFile:dicpath atomically:YES];  NSLog(@"字典存入路径%@",dicpath);  //读取  NSDictionary *newdict = [NSDictionary dictionaryWithContentsOfFile:dicpath];  NSLog( @"读取的字典文件%@",newdict);#pragma mark--- NSData----  NSString *DataPath = [[SandBox getDocuments]stringByAppendingString:@"Data.data"];// NSString *string = @"丑八怪";//  NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];  UIImage *image = [UIImage imageNamed:@"2"];  NSData *data = UIImageJPEGRepresentation(image, 0.5);  [data writeToFile:DataPath atomically:YES];  NSLog(@"%@",DataPath);  //读取  NSData *newData = [NSData dataWithContentsOfFile:DataPath];//  NSString *new = [[NSString alloc]initWithData:newData encoding:4];  UIImage *new = [UIImage imageWithData:newData scale:1];  NSLog(@"%@",newData);  NSLog(@"%@",new);}