IOS-Plist文件存储(1)

1.什么是文件系统？

IOS中每个应用都有自己的文件系统，并有相应的访问权限，一般分为

~/Documents/

~/tmp/

~/Library/Caches/

~/Library/Preferences/-------键值对，不用关心文件路径。

其路径的获取方式为

<span style="color:#999999;">{
    //获取主目录
    NSString *path=NSHomeDirectory();
    NSString *docPath=[path stringByAppendingPathComponent:@"Documents"];
    NSLog(@"%@",docPath);
    //获取文件目录
    NSArray *DocumentPath=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSAllDomainsMask, YES);
    //    NSLog(@"%@",DocumentPath[0]);
    //获取缓存目录
    NSArray *cachePath=NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSAllDomainsMask, YES);
    //    NSLog(@"%@",cachePath[0]);
    //获取临时目录
    NSString *temp=NSTemporaryDirectory();
    //    NSLog(@"%@",temp);
}</span>

Plist文件只能存储NSString NSNumber NSData NSArray NSDictionary的内容，其文件存储为xml格式

NSArray存储到Documents中:

    NSArray *[email protected][@"name",@"age",@"height"];
    NSString *path=NSHomeDirectory();
    NSString *docPath=[path stringByAppendingPathComponent:@"Documents"];
    NSString *filepath=[docPath stringByAppendingPathComponent:@"/aa.plist"];
    //把array存储到plist文件中
    [arr writeToFile:filepath atomically:YES];
    //从文件路径读取为array
    NSArray *arr2=[NSArray arrayWithContentsOfFile:filepath];

NSDictionary存储到Cache中:

NSDictionary *[email protected]{@"name":@"lean",@"age":@24,@"height":@172 };
    NSArray *dicArr=NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSAllDomainsMask, YES);
    NSLog(@"%@",dicArr[0]);
    NSString *dirPath=dicArr[0];
    NSString *filePath=[dirPath stringByAppendingPathComponent:@"dic.plist"];
    //把Dictionary存储到plist文件中
    [dic writeToFile:filePath atomically:YES];
    //从文件路径读取为Dictionary
    NSDictionary *dic2=[NSDictionary dictionaryWithContentsOfFile:filePath ];

NSData读取图片：

//读写图片吧能直接存储 只能通过NSData来存储。
    //以下例子为从UIImageView中存储文件并在另一个控件中读取显示
    NSArray *arr=NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSAllDomainsMask, YES);
    NSLog(@"%@",arr[0]);
    NSString *cachePath=arr[0];
    NSString *filePath=[cachePath stringByAppendingPathComponent:@"image.plist"];
    UIImage *image=[self.a image];
    NSData *data=UIImageJPEGRepresentation(image,1);
    [data writeToFile:filePath atomically:YES];

    NSData *data2=[NSData dataWithContentsOfFile:filePath];
    UIImage *image2=[UIImage imageWithData:data2 ];
    self.b.image=image2;

IOS-Plist文件存储(1)