IOS之文件夹创建、删除，图片在本地的保存和加载

本文转自http://blog.csdn.net/toddmi/article/details/8204102

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// get file absolutely path in the caches directory

NSString* pathInCacheDirectory(NSString *fileName)

{

NSArray *cachePaths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);

NSString *cachePath = [cachePaths objectAtIndex:0];

return [cachePath stringByAppendingPathComponent:fileName];

}

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// get file absolutely path in the caches directory

NSString* pathInCacheDirectory(NSString *fileName)

{

NSArray *cachePaths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);

NSString *cachePath = [cachePaths objectAtIndex:0];

return [cachePath stringByAppendingPathComponent:fileName];

}

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// create directory in the caches directory

bool createDirInCache(NSString *dirName)

{

NSString *imageDir = pathInCacheDirectory(dirName);

BOOL isDir = NO;

NSFileManager *fileManager = [NSFileManager defaultManager];

BOOL existed = [fileManager fileExistsAtPath:imageDir isDirectory:&isDir];

bool isCreated = false;

if ( !(isDir == YES && existed == YES) )

{

isCreated = [fileManager createDirectoryAtPath:imageDir withIntermediateDirectories:YES attributes:nil error:nil];

}

return isCreated;

}

// delete directory in the caches directory

bool deleteDirInCache(NSString *dirName)

{

NSString *imageDir = pathInCacheDirectory(dirName);

BOOL isDir = NO;

NSFileManager *fileManager = [NSFileManager defaultManager];

BOOL existed = [fileManager fileExistsAtPath:imageDir isDirectory:&isDir];

bool isDeleted = false;

if ( isDir == YES && existed == YES )

{

isDeleted = [fileManager removeItemAtPath:imageDir error:nil];

}

return isDeleted;

}

// save Image to the caches directory

bool saveImageToCacheDir(NSString *directoryPath, UIImage *image, NSString *imageName, NSString *imageType)

{

BOOL isDir = NO;

NSFileManager *fileManager = [NSFileManager defaultManager];

BOOL existed = [fileManager fileExistsAtPath:directoryPath isDirectory:&isDir];

bool isSaved = false;

if ( isDir == YES && existed == YES )

{

if ([[imageType lowercaseString] isEqualToString:@"png"])

{

isSaved = [UIImagePNGRepresentation(image) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"png"]] options:NSAtomicWrite error:nil];

}

else if ([[imageType lowercaseString] isEqualToString:@"jpg"] || [[imageType lowercaseString] isEqualToString:@"jpeg"])

{

isSaved = [UIImageJPEGRepresentation(image, 1.0) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"jpg"]] options:NSAtomicWrite error:nil];

}

else

{

NSLog(@"Image Save Failed\nExtension: (%@) is not recognized, use (PNG/JPG)", imageType);

}

}

return isSaved;

}

// load Image from caches dir to imageview

NSData* loadImageData(NSString *directoryPath, NSString *imageName)

{

BOOL isDir = NO;

NSFileManager *fileManager = [NSFileManager defaultManager];

BOOL dirExisted = [fileManager fileExistsAtPath:directoryPath isDirectory:&isDir];

if ( isDir == YES && dirExisted == YES )

{

NSString *imagePath = [directoryPath stringByAppendingString : imageName];

BOOL fileExisted = [fileManager fileExistsAtPath:imagePath];

if (!fileExisted) {

return NULL;

}

NSData *imageData = [NSData dataWithContentsOfFile : imagePath];

return imageData;

}

else

{

return NULL;

}

}

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// create directory in the caches directory

bool createDirInCache(NSString *dirName)

{

NSString *imageDir = pathInCacheDirectory(dirName);

BOOL isDir = NO;

NSFileManager *fileManager = [NSFileManager defaultManager];

BOOL existed = [fileManager fileExistsAtPath:imageDir isDirectory:&isDir];

bool isCreated = false;

if ( !(isDir == YES && existed == YES) )

{

isCreated = [fileManager createDirectoryAtPath:imageDir withIntermediateDirectories:YES attributes:nil error:nil];

}

return isCreated;

}

// delete directory in the caches directory

bool deleteDirInCache(NSString *dirName)

{

NSString *imageDir = pathInCacheDirectory(dirName);

BOOL isDir = NO;

NSFileManager *fileManager = [NSFileManager defaultManager];

BOOL existed = [fileManager fileExistsAtPath:imageDir isDirectory:&isDir];

bool isDeleted = false;

if ( isDir == YES && existed == YES )

{

isDeleted = [fileManager removeItemAtPath:imageDir error:nil];

}

return isDeleted;

}

// save Image to the caches directory

bool saveImageToCacheDir(NSString *directoryPath, UIImage *image, NSString *imageName, NSString *imageType)

{

BOOL isDir = NO;

NSFileManager *fileManager = [NSFileManager defaultManager];

BOOL existed = [fileManager fileExistsAtPath:directoryPath isDirectory:&isDir];

bool isSaved = false;

if ( isDir == YES && existed == YES )

{

if ([[imageType lowercaseString] isEqualToString:@"png"])

{

isSaved = [UIImagePNGRepresentation(image) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"png"]] options:NSAtomicWrite error:nil];

}

else if ([[imageType lowercaseString] isEqualToString:@"jpg"] || [[imageType lowercaseString] isEqualToString:@"jpeg"])

{

isSaved = [UIImageJPEGRepresentation(image, 1.0) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"jpg"]] options:NSAtomicWrite error:nil];

}

else

{

NSLog(@"Image Save Failed\nExtension: (%@) is not recognized, use (PNG/JPG)", imageType);

}

}

return isSaved;

}

// load Image from caches dir to imageview

NSData* loadImageData(NSString *directoryPath, NSString *imageName)

{

BOOL isDir = NO;

NSFileManager *fileManager = [NSFileManager defaultManager];

BOOL dirExisted = [fileManager fileExistsAtPath:directoryPath isDirectory:&isDir];

if ( isDir == YES && dirExisted == YES )

{

NSString *imagePath = [directoryPath stringByAppendingString : imageName];

BOOL fileExisted = [fileManager fileExistsAtPath:imagePath];

if (!fileExisted) {

return NULL;

}

NSData *imageData = [NSData dataWithContentsOfFile : imagePath];

return imageData;

}

else

{

return NULL;

}

}