IOS之数据持久化一

- (void)loadView

{

UIView *aView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];

aView.backgroundColor = [UIColor whiteColor];

self.view = aView;

[aView release];

t1 = [[UITextField alloc]initWithFrame:CGRectMake(80, 30, 80, 30)];

t1.borderStyle = UITextBorderStyleRoundedRect;

t1.text = @"";

[aView addSubview:t1];

t2 = [[UITextField alloc]initWithFrame:CGRectMake(80, 120, 80, 30)];

t2.borderStyle = UITextBorderStyleRoundedRect;

t2.text = @"";

[aView addSubview:t2];

t3 = [[UITextField alloc]initWithFrame:CGRectMake(80, 210, 80, 30)];

t3.borderStyle = UITextBorderStyleRoundedRect;

t3.text = @"";

[aView addSubview:t3];

NSFileManager *fm = [NSFileManager defaultManager];

if ([fm fileExistsAtPath:[self FilePath]]) //如果文件中有，就从文件中取出来,从文件中读取

{

NSArray *arr = [NSArray arrayWithContentsOfFile:[self FilePath]];

t1.text = [arr objectAtIndex:0];

t2.text = [arr objectAtIndex:1];

t3.text = [arr objectAtIndex:2];

}

NSLog(@"%@",[self FilePath]);

//后台运行

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(saveData) name:UIApplicationDidEnterBackgroundNotification object:nil];

}

-(void)saveData

{

NSArray *texts = [NSArray arrayWithObjects:t1.text,t2.text,t3.text, nil];

[texts writeToFile:[self FilePath] atomically:YES];//把数据存到文件中

}

-(NSString *)FilePath

{

//document路径

NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];

NSString *path = [docPath stringByAppendingPathComponent:@"texs"];

return path;

}