iphone Three20如何添加到工程，以及如何添加删除图片的按钮。

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：添加three20到xcode4.2教程

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将three20添加到xcode教程

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，将图片相册添加到工程。

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。导航具体教程

- (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添加删除事件 、添加删除事件2

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];
}
}
}