标签：系统 图片 视频 assetslibrary
@话不多说,直接上代码
#import <AssetsLibrary/AssetsLibrary.h> // 必须导入
// 照片原图路径
#define KOriginalPhotoImagePath [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:@"OriginalPhotoImages"]
// 视频URL路径
#define KVideoUrlPath [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:@"VideoURL"]
// caches路径
#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];
// 测试BarItem
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"测试" style:UIBarButtonItemStylePlain target:self action:@selector(testRun)];
// 测试手势
UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(didClickPanGestureRecognizer:)];
[self.navigationController.view addGestureRecognizer:panRecognizer];
// 图片或者视频的缩略图显示
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的更新记得放在主线程,要不然等子线程排队过来都不知道什么年代了,会很慢的
dispatch_async(dispatch_get_main_queue(), ^{
self.litimgView.image = image;
});
}
// 视频
else if ([[result valueForProperty:ALAssetPropertyType] isEqualToString:ALAssetTypeVideo] ){
// 和图片方法类似
}
}
}];
}];
}
};
ALAssetsLibraryAccessFailureBlock failureBlock = ^(NSError *error)
{
NSString *errorMessage = nil;
switch ([error code]) {
case ALAssetsLibraryAccessUserDeniedError:
case ALAssetsLibraryAccessGloballyDeniedError:
errorMessage = @"用户拒绝访问相册,请在<隐私>中开启";
break;
default:
errorMessage = @"Reason unknown.";
break;
}
dispatch_async(dispatch_get_main_queue(), ^{
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"错误,无法访问!"
message:errorMessage
delegate:self
cancelButtonTitle:@"确定"
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来的路径是无法传输的,必须自己转化成NSData对象重新写入沙盒路径
// 将原始图片的URL转化为NSData数据,写入沙盒
- (void)imageWithUrl:(NSURL *)url withFileName:(NSString *)fileName
{
// 进这个方法的时候也应该加判断,如果已经转化了的就不要调用这个方法了
// 如何判断已经转化了,通过是否存在文件路径
ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init];
// 创建存放原始图的文件夹--->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];
}
});
}
// 将原始视频的URL转化为NSData数据,写入沙盒
- (void)videoWithUrl:(NSURL *)url withFileName:(NSString *)fileName
{
// 解析一下,为什么视频不像图片一样一次性开辟本身大小的内存写入?
// 想想,如果1个视频有1G多,难道直接开辟1G多的空间大小来写?
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;
// 初始化一个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);//没到结尾，没出错，ok继续
}
// 释放缓冲区，关闭文件
free(buffer);
buffer = NULL;
fclose(file);
file = NULL;
}
} failureBlock:nil];
}
});
}
标签：系统 图片 视频 assetslibrary
原文地址：http://blog.csdn.net/hmt20130412/article/details/39054037
