iOS開發之擷取系統相簿中的圖片與視頻(內帶url轉換)

iOS開發之擷取系統相簿中的圖片與視頻(內帶url轉換)

@話不多說,直接上代碼

 

#import   // 必須匯入// 照片原圖路徑#define KOriginalPhotoImagePath   [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:@OriginalPhotoImages]// 視頻URL路徑#define KVideoUrlPath   [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:@VideoURL]// caches路徑#define KCachesPath   [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0]// MainViewController@interface MTHMainViewController ()@property (nonatomic,strong) MTHNextViewController *nextVC;@property (nonatomic,strong) NSMutableArray        *groupArrays;@property (nonatomic,strong) UIImageView           *litimgView;@end@implementation MTHMainViewController- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];    if (self) {        // Custom initialization    }    return self;}- (void)viewDidLoad{    [super viewDidLoad];    // Do any additional setup after loading the view.    self.navigationItem.title = @Demo;    self.view.backgroundColor = [UIColor clearColor];        // 初始化    self.groupArrays = [NSMutableArray array];        // 測試BarItem    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@測試 style:UIBarButtonItemStylePlain target:self action:@selector(testRun)];        // 測試手勢    UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(didClickPanGestureRecognizer:)];    [self.navigationController.view addGestureRecognizer:panRecognizer];        // 圖片或者視頻的縮圖顯示    self.litimgView = [[UIImageView alloc] initWithFrame:CGRectMake(100, 200, 120, 120)];    [self.view addSubview:_litimgView];}- (void)testRun{    __weak MTHMainViewController *weakSelf = self;    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{        ALAssetsLibraryGroupsEnumerationResultsBlock listGroupBlock = ^(ALAssetsGroup *group, BOOL *stop) {            if (group != nil) {                [weakSelf.groupArrays addObject:group];            } else {                [weakSelf.groupArrays enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {                    [obj enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {                        if ([result thumbnail] != nil) {                            // 照片                            if ([[result valueForProperty:ALAssetPropertyType] isEqualToString:ALAssetTypePhoto]){                                                                NSDate *date= [result valueForProperty:ALAssetPropertyDate];                                UIImage *image = [UIImage imageWithCGImage:[result thumbnail]];                                NSString *fileName = [[result defaultRepresentation] filename];                                NSURL *url = [[result defaultRepresentation] url];                                int64_t fileSize = [[result defaultRepresentation] size];                                                                NSLog(@date = %@,date);                                NSLog(@fileName = %@,fileName);                                NSLog(@url = %@,url);                                NSLog(@fileSize = %lld,fileSize);                                                                // UI的更新記得放在主線程,要不然等子線程排隊過來都不知道什麼年代了,會很慢的                                dispatch_async(dispatch_get_main_queue(), ^{                                    self.litimgView.image = image;                                });                            }                            // 視頻                            else if ([[result valueForProperty:ALAssetPropertyType] isEqualToString:ALAssetTypeVideo] ){                                                            // 和圖片方法類似                            }                        }                    }];                }];            }        };                ALAssetsLibraryAccessFailureBlock failureBlock = ^(NSError *error)        {                        NSString *errorMessage = nil;                        switch ([error code]) {                case ALAssetsLibraryAccessUserDeniedError:                case ALAssetsLibraryAccessGloballyDeniedError:                    errorMessage = @使用者拒絕訪問相簿,請在<隱私>中開啟;                    break;                                    default:                    errorMessage = @Reason unknown.;                    break;            }                        dispatch_async(dispatch_get_main_queue(), ^{                UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@錯誤,無法訪問!                                                                   message:errorMessage                                                                  delegate:self                                                         cancelButtonTitle:@確定                                                         otherButtonTitles:nil, nil];                [alertView show];            });        };                        ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc]  init];        [assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAll                                     usingBlock:listGroupBlock failureBlock:failureBlock];    });}

 

@但是:

按照上面方法直接取出來的路徑是無法傳輸的,必須自己轉化成NSData對象重新寫入沙箱路徑

 

// 將原始圖片的URL轉化為NSData資料,寫入沙箱- (void)imageWithUrl:(NSURL *)url withFileName:(NSString *)fileName{    // 進這個方法的時候也應該加判斷,如果已經轉化了的就不要調用這個方法了    // 如何判斷已經轉化了,通過是否存在檔案路徑    ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init];    // 建立存放原始圖的檔案夾--->OriginalPhotoImages    NSFileManager * fileManager = [NSFileManager defaultManager];    if (![fileManager fileExistsAtPath:KOriginalPhotoImagePath]) {        [fileManager createDirectoryAtPath:KOriginalPhotoImagePath withIntermediateDirectories:YES attributes:nil error:nil];    }    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{        if (url) {            // 主要方法            [assetLibrary assetForURL:url resultBlock:^(ALAsset *asset) {                ALAssetRepresentation *rep = [asset defaultRepresentation];                Byte *buffer = (Byte*)malloc((unsigned long)rep.size);                NSUInteger buffered = [rep getBytes:buffer fromOffset:0.0 length:((unsigned long)rep.size) error:nil];                NSData *data = [NSData dataWithBytesNoCopy:buffer length:buffered freeWhenDone:YES];                NSString * imagePath = [KOriginalPhotoImagePath stringByAppendingPathComponent:fileName];                [data writeToFile:imagePath atomically:YES];            } failureBlock:nil];        }    });}// 將原始視頻的URL轉化為NSData資料,寫入沙箱- (void)videoWithUrl:(NSURL *)url withFileName:(NSString *)fileName{    // 解析一下,為什麼視頻不像圖片一樣一次性開闢本身大小的記憶體寫入?    // 想想,如果1個視頻有1G多,難道直接開闢1G多的空間大小來寫?    ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init];    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{        if (url) {            [assetLibrary assetForURL:url resultBlock:^(ALAsset *asset) {                ALAssetRepresentation *rep = [asset defaultRepresentation];                NSString * videoPath = [KCachesPath stringByAppendingPathComponent:fileName];                char const *cvideoPath = [videoPath UTF8String];                FILE *file = fopen(cvideoPath, a+);                if (file) {                    const int bufferSize = 1024 * 1024;                    // 初始化一個1M的buffer                    Byte *buffer = (Byte*)malloc(bufferSize);                    NSUInteger read = 0, offset = 0, written = 0;                    NSError* err = nil;                    if (rep.size != 0)                    {                        do {                            read = [rep getBytes:buffer fromOffset:offset length:bufferSize error:&err];                            written = fwrite(buffer, sizeof(char), read, file);                            offset += read;                        } while (read != 0 && !err);//沒到結尾，沒出錯，ok繼續                    }                    // 釋放緩衝區，關閉檔案                    free(buffer);                    buffer = NULL;                    fclose(file);                    file = NULL;                }            } failureBlock:nil];        }    });}