前言：本来要更新NSURLSession的UploadTask的，结果写那个Demo的时候想要写成拍照上传，然后就想到先写一个关于拍照的Demo吧。本文会先介绍下如何使用系统提供的界面拍照和选择相册，然后自定义拍照界面。注意，本文使用的是UIImagePickerController,所以不能完全的自定义，如果想要彻底的自定义拍照，建议选择AV Foundation这个框架来做
Demo效果
进入系统的拍照界面
进入自定义拍照界面
自定义前置摄像头和后置摄像头切换动画－翻页
一 使用系统提供的界面拍照和相册选择
第一步
保存一个UIImagePickerController的实例，然后适当的时候初始化始化。Demo选择在viewDidLoad初始化。让当前类实现UIImagePickerControllerDelegate,UINavigationControllerDelegate两个代理
@property (strong,nonatomic)UIImagePickerController * imagePikerViewController; //初始化 self.imagePikerViewController = [[UIImagePickerController alloc] init]; self.imagePikerViewController.delegate = self;//通过代理来传递拍照的图片 self.imagePikerViewController.allowsEditing = YES;//允许编辑
第二步，通过ActionSheet来让用户选择是拍照还是到相册选择，然后模态的显示
[self presentViewController:self.imagePikerViewController animated:YES completion:NULL];
注意，要先判断相机是否可用，然后在进入相机（有可能相机坏了，或者在虚拟机上运行的）
UIAlertController * alertController = [UIAlertController alertControllerWithTitle: nil
message: nil
preferredStyle:UIAlertControllerStyleActionSheet];
[alertController addAction: [UIAlertAction actionWithTitle: @"Take Photo" style: UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]){
self.imagePikerViewController.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentViewController:self.imagePikerViewController animated:YES completion:NULL];
}else{
[self showAlertWithMessage:@"Camera is not available in this device or simulator"];
}
}]];
[alertController addAction: [UIAlertAction actionWithTitle: @"Choose Existing Photo" style: UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]){
self.imagePikerViewController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
[self presentViewController:self.imagePikerViewController animated:YES completion:NULL];
}
}]];
[alertController addAction: [UIAlertAction actionWithTitle: @"Cancel" style: UIAlertActionStyleCancel handler:nil]];
[self presentViewController: alertController animated: YES completion: nil];第三部，代理函数处理拍照或者cancel事件
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
UIImage * image = info[UIImagePickerControllerEditedImage];
if (!image) {
image = info[UIImagePickerControllerOriginalImage];
}
self.imageview.image = image;
[self dismissViewControllerAnimated:YES completion:NULL];
}
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
[self dismissViewControllerAnimated:YES completion:NULL];
}二 自定义拍照界面
UIImagePickerController的自定义界面比较简单，通过设置cameraOverlayView这个属性为自定义的View就能自定义。
第一步 创建一个View
创建xib文件
拖拽控件，进行autoLayout，最终效果如图
把fileOwner设置成CustomTakePhotoViewController
第二步 在显示拍照界面之前，把UI设置成自己想要的，注意，把属性
showsCameraControls设置为NO，不让默认的界面出现。
self.imagePikerViewController.sourceType = UIImagePickerControllerSourceTypeCamera; self.imagePikerViewController.showsCameraControls = NO; [[NSBundle mainBundle] loadNibNamed:@"CustomOverLayview" owner:self options:nil]; self.takePictureButton.layer.cornerRadius = 20; self.takePictureButton.clipsToBounds = YES; self.overlayView.frame = self.imagePikerViewController.cameraOverlayView.frame; self.overlayView.backgroundColor = [UIColor clearColor]; self.imagePikerViewController.cameraOverlayView = self.overlayView; self.overlayView = nil; [self presentViewController:self.imagePikerViewController animated:YES completion:NULL];
第三步，为view上的控件添加动作
Segment Control负责切换前置摄像头和后置摄像头，为了流畅，在切换的时候显示动画。
- (IBAction)cameraSelect:(UISegmentedControl *)sender{
NSInteger index = sender.selectedSegmentIndex;
if (index == 0) {
[UIView transitionWithView:self.imagePikerViewController.view duration:1.0 options:UIViewAnimationOptionAllowAnimatedContent | UIViewAnimationOptionTransitionCurlDown animations:^{
self.imagePikerViewController.cameraDevice = UIImagePickerControllerCameraDeviceFront;
} completion:NULL];
}else{
[UIView transitionWithView:self.imagePikerViewController.view duration:1.0 options:UIViewAnimationOptionAllowAnimatedContent | UIViewAnimationOptionTransitionCurlUp animations:^{
[self.imagePikerViewController setCameraDevice:UIImagePickerControllerCameraDeviceRear];
} completion:NULL];
}
}拍照的Button
- (IBAction)takePicture:(id)sender {
[self.imagePikerViewController takePicture];
}取消的Button
- (IBAction)cancelTakePicture:(id)sender {
[self dismissViewControllerAnimated:YES completion:NULL];
}第四步 在代理中处理图片
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
UIImage * image = info[UIImagePickerControllerEditedImage];
if (!image) {
image = info[UIImagePickerControllerOriginalImage];
}
self.imageview.image = image;
[self dismissViewControllerAnimated:YES completion:NULL];
}注意，如果log输出
Snapshotting a view that has not been rendered results in an empty snapshot. Ensure your view has been rendered at least once before snapshotting or snapshot after screen updates.
直接忽略就是了，没有任何影响，貌似是IOS 8的一个bug
