文件操作 检查文件是否存在 创建文件目录

关于文件目录的操作和检查

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- (NSString *)dataPath:(NSString *)file  
{

NSString *path = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"badge"];
BOOL bo = [[NSFileManager defaultManager] createDirectoryAtPath:path withIntermediateDirectories:YES attributes:nil error:nil];
NSAssert(bo,@"创建目录失败");

NSString *result = [path stringByAppendingPathComponent:file];

return result;

}

文件目录操作和文件创建(图片)

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- (void)viewDidLoad  
{
[super viewDidLoad];
//此处首先指定了图片存取路径(默认写到应用程序沙盒 中)
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);

//并给文件起个文件名
NSString *imageDir = [[[paths objectAtIndex:0] stringByAppendingPathComponent:@"163"] stringByAppendingPathComponent:@"songzi"];

//存放图片的文件夹
NSString *imagePath =[imageDir stringByAppendingPathComponent:@"文件名.png"];

NSData *data = nil;

//检查图片是否已经保存到本地
if([self isExistsFile:imagePath]){
data=[NSData dataWithContentsOfFile:imagePath];
}else{
data = [NSData dataWithContentsOfURL:[NSURL URLWithString: @"网址"]];

//创建文件夹路径
[[NSFileManager defaultManager] createDirectoryAtPath:imageDir withIntermediateDirectories:YES attributes:nil error:nil];

//创建图片
[UIImagePNGRepresentation([UIImage imageWithData:data]) writeToFile:imagePath atomically:YES];
}
imageView.image = [UIImage imageWithData:data];
}

检查文件是否存在

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NSString *path = [[NSBundle mainBundle] pathForResource:fileName ofType:@""];
if(path==NULL)