ios 读写文件-复习篇

来源：互联网发布：apache 2.4 windows 编辑：程序博客网时间：2024/05/21 11:21

//创建文件管理器

NSFileManager *fileManager = [NSFileManager defaultManager];

//获取路径

//参数NSDocumentDirectory要获取那种路径

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);

NSString *documentsDirectory = [paths objectAtIndex:0];

//更改到待操作的目录下

[fileManager changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]];

//创建文件fileName文件名称，contents文件的内容，如果开始没有内容可以设置为nil，attributes文件的属性，初始为nil

[fileManager createFileAtPath:@"fileName" contents:nil attributes:nil];

//删除待删除的文件

[fileManager removeItemAtPath:@"createdNewFile" error:nil];

写入数据：

//获取文件路径NSString *path = [documentsDirectory stringByAppendingPathComponent:@"fileName"];//待写入的数据NSString *temp = @”Welcome to blog.iosxcode4.com”;int data0 = 100000;float data1 = 23.45f;//创建数据缓冲NSMutableData *writer = [[NSMutableData alloc] init];//将字符串添加到缓冲中[writer appendData:[temp dataUsingEncoding:NSUTF8StringEncoding]];//将其他数据添加到缓冲中[writer appendBytes:&data0 length:sizeof(data0)];[writer appendBytes:&data1 length:sizeof(data1)];//将缓冲的数据写入到文件中[writer writeToFile:path atomically:YES];[writer release];

//获取文件路径

NSString *path = [documentsDirectorystringByAppendingPathComponent:@"fileName"];

//待写入的数据

NSString *temp = @”Welcome to blog.iosxcode4.com”;

int data0 = 100000;

float data1 = 23.45f;

//创建数据缓冲

NSMutableData *writer = [[NSMutableData alloc] init];

//将字符串添加到缓冲中

[writer appendData:[tempdataUsingEncoding:NSUTF8StringEncoding]];

//将其他数据添加到缓冲中

[writer appendBytes:&data0 length:sizeof(data0)];

[writer appendBytes:&data1 length:sizeof(data1)];

//将缓冲的数据写入到文件中

[writer writeToFile:path atomically:YES];

[writer release];

读取数据：

int gData0;float gData1;NSString *gData2;NSData *reader = [NSData dataWithContentsOfFile:path];gData2 = [[NSString alloc] initWithData:[reader subdataWithRange:NSMakeRange(0, [temp length])]encoding:NSUTF8StringEncoding];[reader getBytes:&gData0 range:NSMakeRange([temp length], sizeof(gData0))];[reader getBytes:&gData2 range:NSMakeRange([temp length] + sizeof(gData0), sizeof(gData1))];NSLog(@”gData0:%@ gData1:%i gData2:%f”, gData0, gData1, gData2);

int gData0;

float gData1;

NSString *gData2;

NSData *reader = [NSData dataWithContentsOfFile:path];

gData2 = [[NSString alloc] initWithData:[reader subdataWithRange:NSMakeRange(0, [temp length])]

encoding:NSUTF8StringEncoding];

[reader getBytes:&gData0 range:NSMakeRange([temp length], sizeof(gData0))];

[reader getBytes:&gData2 range:NSMakeRange([temp length] + sizeof(gData0),sizeof(gData1))];

NSLog(@”gData0:%@ gData1:%i gData2:%f”, gData0, gData1, gData2);

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