在沙盒中存取圖片

-(BOOL) saveImage:(UIImage*)img withName:(NSString*)fileName

{

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

NSString* path = [paths objectAtIndex:0];

NSString* filePath = [path stringByAppendingPathComponent:fileName];

NSData *data = [NSData dataWithData:UIImagePNGRepresentation(img)];

BOOL ret = [data writeToFile:filePath atomically:YES];

return ret;

}

-(UIImage*) getImageFileWithName:(NSString*)fileName

{

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

NSString *path = [paths objectAtIndex:0];

NSString* filePath = [path stringByAppendingPathComponent:fileName];

NSError* err = [[NSError alloc] init];

NSData* data = [[NSData alloc] initWithContentsOfFile:filePath

  options:NSDataReadingMapped

error:&err];

UIImage* img = nil;

if(data != nil)

{

img = [[[UIImage alloc] initWithData:data] autorelease];

[data release];

}

else

{

NSLog(@"getImageFileWithName error code : %d",[err code]);

}

return img;

}

注：保存圖片的時候，如果沙盒中已經有了名爲fileName的圖片數據的話，再次保存的話會覆蓋原來的圖片數據。