最近由于项目需要，需要做一个相册查看器来查看项目截图的图片。于是发现Three20的功能很强大，有自带的相册功能，于是就将其引用到工程里头来。
首先是要下载three20并安装到工程里头。
如果是想手动将three20添加到xcode4.2的话，可参照此链接：
如果想通过指令来将three20添加到xcode的话，可参照此链接
通过指令来将three20添加到xcdoe时，操作比较快速。
但有几点需要注意。
1.尽量让下载的three20 与工程处于同一个目录，这样在后续的设置中会比较方便。
2.如果PROJECT的名称与TARGETS的名称不一样的话，那通过指令执行时，需要执行如下指令。
3.接着按这些步骤把相册添加到自己的工程中去，
3，如何在现有的程序中单击某一按钮，然后导航到three20的相册中。代码如下：如果想进一步的了解导航具体情况，那么可以参照此链接。
- (IBAction)viewPhoto:(id)sender
{
NSLog(
@" %@ ",currentImageName);
NSLog(
@" %d ",[currentImageName retainCount]);
[[TTURLRequestQueue mainQueue] setMaxContentLength:
0];
TTNavigator *navigator = [TTNavigator navigator];
navigator.window = [UIApplication sharedApplication].keyWindow;
TTURLMap *map = navigator.URLMap;
[map
from:
@" tt://appPhotos " toSharedViewController:[PhotoViewController
class]];
[navigator openURLAction:[TTURLAction actionWithURLPath:
@" tt://appPhotos "]];
}
4，如果想从相册返回到原工程，可以在PhotoViewController.h 添加如下代码：
4.1添加返回按钮到导航栏
- (void) viewDidLoad {
UIBarButtonItem *listViewBackBtn = [[UIBarButtonItem alloc] initWithTitle:
@" test " style:UIBarButtonItemStylePlain
target:self
action:@selector(GoBack:)];
self.navigationItem.leftBarButtonItem = listViewBackBtn;
self.navigationItem.hidesBackButton = YES;
[listViewBackBtn release];
self.photoSource = [PhotoSet samplePhotoSet];
self.centerPhotoIndex = currentCaptureIndex;
}
4.2添加返回按钮事件
//返回到视频观看页面
-(
void) GoBack:(id)sender{
[[TTNavigator navigator] removeAllViewControllers];
}
5.如何在相册中添加删除事件。
5.1具体添加删除按钮以及事件可以参照此教程 、
5.2 删除后的图片中兴的事件。如下：
//删除图片
- (
void)deletePhotoAtIndex:(NSInteger)index
{
NSMutableArray *muPhotos = [PhotoSet samplePhotoSet].photos;
Photo *removePhoto = [muPhotos objectAtIndex:index];
NSString *removePhotoName = removePhoto.caption;
[self removePhotosOfDocuments:index removePhotoName:removePhotoName];
// [muPhotos removeObjectAtIndex:index]; self.photoSource = [PhotoSet samplePhotoSet];
self.centerPhotoIndex = index;
}
- (
void) removePhotosOfDocuments:(NSInteger)index removePhotoName:(NSString *) removePhotoName
{
NSFileManager *fileManage = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask , YES) ;
NSString *documentDirectory = [paths objectAtIndex:
0];
NSString *bigImagePath = [documentDirectory stringByAppendingPathComponent:[NSString stringWithFormat:
@" BigImage/%@ ",removePhotoName]];
NSString *smallImagePath = [documentDirectory stringByAppendingPathComponent:[NSString stringWithFormat:
@" SmallImage/small_%@ ",removePhotoName]];
NSError *error = nil;
[fileManage removeItemAtPath:bigImagePath error:&error];
[fileManage removeItemAtPath:smallImagePath error:&error];
}
5.3如果上传某一张图片，然后返回照片缩略图查看器，结果发现照片缩略图查看器中被删除的图片还在，这时需要修改TTPhotoViewController这个类的方法：红色部分为新添加的。这样才能保持相册缩略图的同步。
TTPhotoViewController
- (
void)showThumbnails {
NSString* URL = [self URLForThumbnails];
if (!_thumbsController) {
if (URL) {
// The photo source has a URL mapping in TTURLMap, so we use that to show the thumbs NSDictionary* query = [NSDictionary dictionaryWithObject:self forKey:
@" delegate "];
TTBaseNavigator* navigator = [TTBaseNavigator navigatorForView:self.view];
_thumbsController = [[navigator viewControllerForURL:URL query:query] retain];
[navigator.URLMap setObject:_thumbsController forURL:URL];
}
else {
// The photo source had no URL mapping in TTURLMap, so we let the subclass show the thumbs _thumbsController = [[self createThumbsViewController] retain];
_thumbsController.photoSource = _photoSource;
}
}
if (URL) {
TTOpenURLFromView(URL, self.view);
}
else {
if ([self.navigationController isKindOfClass:[TTNavigationController
class]]) {
_thumbsController.photoSource = _photoSource; [(TTNavigationController*)self.navigationController
pushViewController: _thumbsController
animatedWithTransition: UIViewAnimationTransitionCurlDown];
}
else {
_thumbsController.photoSource = _photoSource; [self.navigationController pushViewController:_thumbsController animated:YES];
}
}
}