iOS 文件的读取和写入

来源：互联网发布：怪物猎人捏脸数据库编辑：程序博客网时间：2024/06/06 21:43

//找到路径+(NSString *)findDocumentPath{    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString * path = [paths firstObject];    NSLog(@"path === %@",path);    return path;}//字符串写入+(BOOL)writeStringValue{    NSString * temp =[WriteAndRead readNsstringValue];    BOOL result = NO;//    查看文件里面有没有内容 没有的话直接写入有就字符串拼接    if (temp.length>0) {        NSString * str = [NSString stringWithFormat:@"%@行尸走肉",temp];        //     类名调用        NSString * path= [WriteAndRead  findDocumentPath];        NSString * realpath = [NSString stringWithFormat:@"%@/hellow.txt",path];        //    错误信息        NSError * error = Nil;        result =  [str writeToFile:realpath atomically:YES encoding:NSUTF8StringEncoding error:&error];    }    else{        NSString * str = @"横尸遍野";        //     类名调用        NSString * path= [WriteAndRead  findDocumentPath];        NSString * realpath = [NSString stringWithFormat:@"%@/hellow.txt",path];        //    错误信息        NSError * error = Nil;        result =  [str writeToFile:realpath atomically:YES encoding:NSUTF8StringEncoding error:&error];    }     //    取地址呦 指向指针的指针 双**    return result;}//数组写入+(BOOL)writeArrayValue{    NSArray * arr = [[NSArray alloc] initWithObjects:@"1",@"2",@"3", nil];    NSString * path = [WriteAndRead findDocumentPath];    NSString * realpath = [NSString stringWithFormat:@"%@/arr.txt",path];     BOOL result =  [arr writeToFile:realpath atomically:YES];    return result;}//数据data写入+(BOOL)writeDataValue{    NSString * str = [NSString stringWithFormat:@"来自星星的xx"];    NSData * data = [str dataUsingEncoding:NSUTF8StringEncoding];    NSString * path = [WriteAndRead findDocumentPath];    NSString * realpath = [NSString stringWithFormat:@"%@/data.txt",path];    BOOL result = [data writeToFile:realpath atomically:YES];    return result;}

接下来开始读取文件

//读取字符串+(NSString * )readNsstringValue{    NSString * path  =[WriteAndRead findDocumentPath];    NSString * realpath = [NSString stringWithFormat:@"%@/hellow.txt",path];    NSString * value = [[NSString alloc] initWithContentsOfFile:realpath encoding:NSUTF8StringEncoding error:NULL];    return [value autorelease];//    加号方法就不用autorelease}// 数组的读取+(NSArray *)readArrayValue{    NSString * path = [WriteAndRead findDocumentPath];    NSString * realpath = [NSString stringWithFormat:@"%@/arr.txt",path];    NSArray * value = [NSArray arrayWithContentsOfFile:realpath];    return value;}// data的读取+(NSData*)readDataValue{    NSString * path = [WriteAndRead findDocumentPath];    NSString * realpath = [NSString stringWithFormat:@"%@/data.txt",path];    NSData * value = [NSData dataWithContentsOfFile:realpath];    return value;        }

下一集会详细介绍数据库的创建及基本数据库语句

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