Objective-C NSString、NSArray、NSDictionary、NSData 存取至Document-优快云博客

本文链接：https://blog.youkuaiyun.com/skyfromchina/article/details/18081861

本文介绍了如何在iOS应用中进行基本的数据读写操作，包括字符串、数组和字典的存储及检索过程。通过实例展示了使用Objective-C语言进行文件路径获取、数据写入与读取的具体实现方法。

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//-(void)writeButtonAction:(id)sender{
//    //获得沙盒路径
//    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
//    //NSDocumentDirectory documents文件夹
//    // NSUserDomainMask 用户根目录
//    NSString * nowPath = [paths objectAtIndex:0];
//    NSLog(@"%@",nowPath);
//    /*
//     *字符串写入
//     */
//    //为要添加的str创建一个文件  后缀写不写都行 必须创建 不然它不知道该存在哪里
//    NSString * stringPath = [NSString stringWithFormat:@"%@/newStr.txt",nowPath];
//    NSString * str = @"dfkl;ghadksjasfklfhdsaklk;bvhsadflvkdfbgjvbfgdsa.kfhdsaokfgds;k";
//    [str writeToFile:stringPath atomically:YES encoding:NSUTF8StringEncoding error:NULL];
//}
//
//-(void)readButtonAction:(id)sender{
//    //获得沙盒路径
//    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
//    NSLog(@"%@",paths);
//    NSString * nowPath = [paths objectAtIndex:0];
//    //获得文件路径
//    NSString * stringPath = [NSString stringWithFormat:@"%@/newStr.txt",nowPath];
//    //取数据存入readStr
//    NSString * readStr = [[[NSString alloc] initWithContentsOfFile:stringPath encoding:NSUTF8StringEncoding error:NULL] autorelease];
//    NSLog(@"%@",readStr);
//}
//
/*
 *数组的存取
 */
//-(void)writeButtonAction:(id)sender{
//    NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
//    NSString * newPath = [NSString stringWithFormat:@"%@/array.txt",path];
//    NSArray * arr = [NSArray arrayWithObjects:@"redColor",@"greenColor",@"blueColor", nil];
//    [arr writeToFile:newPath atomically:YES];
//    NSLog(@"write Done");
//}
//
//-(void)readButtonAction:(id)sender{
//    NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
//    NSString * newPath = [NSString stringWithFormat:@"%@/array.txt",path];
//    NSArray * arr = [[[NSArray alloc]initWithContentsOfFile:newPath]autorelease];
//    NSLog(@"%@",arr);
//}

/*
 *字典的存取
 */
//-(void)writeButtonAction:(id)sender{
//    NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
//    NSString * newPath = [NSString stringWithFormat:@"%@/dic.txt",path];
//    NSDictionary * dic = [NSDictionary dictionaryWithObjectsAndKeys:@"value1",@"key1",@"value2",@"key2",@"value3",@"key3", nil];
//    [dic writeToFile:newPath atomically:YES];
//    NSLog(@"done!");
//}
//
//-(void)readButtonAction:(id)sender{
//    NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
//    NSString * newPath = [NSString stringWithFormat:@"%@/dic.txt",path];
//    NSDictionary * dic = [[[NSDictionary alloc]initWithContentsOfFile:newPath] autorelease];
//    NSLog(@"%@",dic);
//}
/*
 *NSData
 */
-(void)writeButtonAction:(id)sender{
    NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString * newPath = [NSString stringWithFormat:@"%@/date.txt",path];
    NSString * strDD = @"sdflas;fjsalgdj;aghdf;gdlfh";
    //将字符串转换成date
    NSData * date = [strDD dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
    [date writeToFile:newPath atomically:YES];
}

-(void)readButtonAction:(id)sender{
    NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString * newPath = [NSString stringWithFormat:@"%@/date.txt",path];
    NSData * data = [NSData dataWithContentsOfFile:newPath];
    //将data转换成字符串
    NSString * string = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
    NSLog(@"%@",string);
}