IOSは指定されたパスのファイルが存在するかどうかを検出する。

- (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,@"      ");  

    NSString *result = [path stringByAppendingPathComponent:file];  

    return result;  

}   

- (void)viewDidLoad  

{  

    [super viewDidLoad];   

    //             （            ）  

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);  

    //           

    NSString *imageDir = [[[paths objectAtIndex:0] stringByAppendingPathComponent:@"163"] stringByAppendingPathComponent:@"songzi"];  

    //          

    NSString *imagePath =[imageDir stringByAppendingPathComponent:@"   .png"];  

    NSData *data = nil;  

    //               

    if([self isExistsFile:imagePath]){  

        data=[NSData dataWithContentsOfFile:imagePath];  

    }else{  

        data = [NSData dataWithContentsOfURL:[NSURL URLWithString: @"  "]];  

        //         

        [[NSFileManager defaultManager] createDirectoryAtPath:imageDir withIntermediateDirectories:YES attributes:nil error:nil];  

        //      

        [UIImagePNGRepresentation([UIImage imageWithData:data]) writeToFile:imagePath atomically:YES];           

    }  

    imageView.image = [UIImage imageWithData:data];  

}  

ファイルが存在するかどうかを確認します。

NSString *path = [[NSBundle mainBundle] pathForResource:fileName ofType:@""];

if(path==NULL)

方法二：

NSFileManager *fileManager = [NSFileManager defaultManager];

   //Get documents directory

   NSArray *directoryPaths = NSSearchPathForDirectoriesInDomains

   (NSDocumentDirectory, NSUserDomainMask, YES);

   NSString *documentsDirectoryPath = [directoryPaths objectAtIndex:0];

   if ([fileManager fileExistsAtPath:@""]==YES) {

        NSLog(@"File exists");

    }   

方法三：

//        

    if(![c judgeFileExist:@"user.plist"])       

    {

        NSLog(@"          ！");

        return;

    }

方法四：

//        

-(BOOL)judgeFileExist:(NSString * )fileName

{

    //      

    NSString *path = [[NSBundle mainBundle] pathForResource:fileName ofType:@""];

    if(path==NULL)

        return NO;

    returnYES;

}