UIPopverController,UIImagePickerController,图片选取。

/*使用UIImagePickerController和UIPopverController， 先在头文件中设置要遵循的协议：<UINavigationControllerDelegate,UIImagePickerControllerDelegate,UIPopoverControllerDelegate>*/

@implementation PickerVC

{

/*UIPopoverController must use the global variable*/

UIPopoverController *_popController;

UIBarButtonItem *_popbbi;

UIImageView *_imageView;

}

#pragma mark - UIImagePickerControllerDelegate

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{

/*

1.implicit conversion of Objective-C pointer type 'NSDictionary *'to C pointer type 'CFTypeRef'(asa'const void'*)required a bridged cast

2.Use __bridge to convert directly(no change in ownership)

3.void CFShow (CFTypeRef obj);Prints a description of a Core Foundation object to stderr.

*/

CFShow((__bridge CFTypeRef)(info));

_imageView = [[UIImageView alloc] initWithFrame:CGRectMake(100, 300, 300, 300)];

_imageView.image = [info objectForKey:@"UIImagePickerControllerEditedImage"];

[self.view addSubview:_imageView];

//如果是在iPad中使用的UIPopverController，则下面这个方法没有被调用。

[self dismissViewControllerAnimated:YES completion:^{

printf("UIImagePickerControllerEditedImage:edited chose!\n");

}];

}

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker

{

[picker dismissViewControllerAnimated:YES completion:^{

printf("dismissViewController!\n");

}];

}

-(void)pickImage:(id)sender{

UIImagePickerController *ipc = [[UIImagePickerController alloc] init];

ipc.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

ipc.delegate = self;

ipc.allowsEditing = YES;//这个设置是选取图片的关键。

//进行硬件环境判断，如果是iPad，可以使用UIPopoverController,但是如果是在iPhone环境中则不能使用UIPopverController，否则会Crash。

if (UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPad) {

_popController = [[UIPopoverController alloc] initWithContentViewController:ipc];

_popController.delegate = self;

[_popController presentPopoverFromBarButtonItem:self.navigationItem.rightBarButtonItem permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];

return;

}

//iPhone中一般使用下面这个方法就可以了。iPad也可以使用

[self presentViewController:ipc animated:YES completion:^{

}];

}

-(void)popbbiClick:(UIBarButtonItem *)popbbi{

printf("click popbbi\n");

PickImageViewController *pvc = [[PickImageViewController alloc] init];

[self.navigationController pushViewController:pvc animated:YES];

}

- (void)viewDidLoad

{

[super viewDidLoad];

// Do any additional setup after loading the view.

self.navigationItem.rightBarButtonItem = kBarButton(@"Pick", @selector(pickImage:));

self.title = @"Image Picker";

_popbbi = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemBookmarks target:self action:@selector(popbbiClick:)];

self.navigationItem.leftBarButtonItem = _popbbi;

}

=======================下面再使用一次

@implementation PickImageViewController

{

UIImagePickerController *_pvc;

UIPopoverController *_popController;

UIImageView *_imageView;

UIImage *_image;

}

-(void)initUIItems{

_pvc = [[UIImagePickerController alloc] init];

_pvc.delegate = self;

_pvc.allowsEditing = YES;//要使用选中的Medio内容需要设置这个为YES。

_pvc.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

_imageView = [[UIImageView alloc] initWithFrame:CGRectMake(100, 100, 300, 300)];

_imageView.backgroundColor = [UIColor yellowColor];

_imageView.userInteractionEnabled = YES;

[self.view addSubview:_imageView];

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapTouched:)];

tap.numberOfTapsRequired = 2;

[_imageView addGestureRecognizer:tap];

}

-(void)tapTouched:(UIGestureRecognizer *)tap{

if (UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPad) {

UIPopoverController *popvc = [[UIPopoverController alloc] initWithContentViewController:_pvc];

popvc.delegate = self;

/*这里需要注意，对局部UIPopoverController对象popover我们赋给了一个全局的UIPopoverController对象popoverController。而不能直接调用popover。因为在popover对象还可见时，是不能够被释放的。

Popover controllers are for use exclusively on iPad devices. Attempting to create one on other devices results in an exception. */

_popController = popvc;

[_popController presentPopoverFromRect:CGRectMake(100, 100, 400,400) inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];

return;

}

/*在iPhonez中可以直接使用下面的方法，但是在iPad中需要使用到上面的UIPopoverController，但是记住还是需要ImagePicker的代理方法，否则选不到图片，其实不同点就在上面这一点上。*/

[self presentViewController:_pvc animated:YES completion:^{

printf("PresentViewController: open ImagePicker menu!\n");

}];

}

/*下面的代理方法依然不变！*/

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{

_image = (UIImage *)[info objectForKey:@"UIImagePickerControllerOriginalImage"];

_imageView.image = _image;

[self dismissViewControllerAnimated:YES completion:^{

printf("Picker choose the oneImage and dismissViewController\n");

}];

}

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{

[self dismissViewControllerAnimated:YES completion:^{

printf("ImagePicker menu DismissViewController\n");

}];

}

=======

对于iPad来说，可以选择UIPopverController来使用UIImagePickerController，

因为iPad的大屏关系，这样使用其实有更好的用户体验，另外注意代理设置，可编辑属性设置，

_pvc.allowsEditing = YES;//要使用选中的Image需要设置这个为YES。

ipc.allowsEditing = YES;//这个设置是选取图片的关键。

注意UIPopverController只能再iPad环境下使用。

if (UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPad) {}else Crash~