相机拍照

通过UIImagePickerController来实现调用手机相机或则打开手机相册

（一）头文件

#import <UIKit/UIKit.h>

@interface CameraViewController : UIViewController<UIImagePickerControllerDelegate, UINavigationControllerDelegate>

@end

（二）初始化UIImagePickerController变量，并设置委托

@interface CameraViewController ()
{
    UIImagePickerController *imagePicker;
    UIImageView *imageView;
}
@end

@implementation CameraViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor=[UIColor blackColor];
    
    imagePicker=[[UIImagePickerController alloc] init];
    imagePicker.modalPresentationStyle = UIModalPresentationOverCurrentContext;
    imagePicker.delegate=self;
    // Do any additional setup after loading the view.
}

@end

(三）拍照

    imagePicker.allowsEditing = YES;
    if ([UIImagePickerController isSourceTypeAvailable:
         UIImagePickerControllerSourceTypeCamera])
    {
        imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
    }
    

（四）相册选择照片

    imagePicker.allowsEditing = YES;
    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

（五）实现委托

不管是新拍的照片还是在相册中选择照片，最终会在操作结束后通过委托形式传递到ui上

-(void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    [self dismissViewControllerAnimated:YES completion:^{}];
    
    UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];
    if (image == nil) {
        image = [info objectForKey:UIImagePickerControllerOriginalImage];
        NSLog(@"Image null");
    }
    imageView.image = image;
    NSLog(@"Photo selected");
}

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
    [self dismissViewControllerAnimated:YES completion:^{}];
    NSLog(@"Photo dimiss");
}

//------------------------------------完整代码---------------------------------------------//

#import "CameraViewController.h"

@interface CameraViewController ()
{
    UIImagePickerController *imagePicker;
    UIImageView *imageView;
}
@end

@implementation CameraViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor=[UIColor blackColor];
    self.modalPresentationStyle=UIModalPresentationOverCurrentContext;
    
    imageView=[[UIImageView alloc] init];
    imageView.frame=CGRectMake(100, 50, 200, 300);
    UIImage *uiImage=[UIImage imageNamed:@"Example.png"];
    [imageView setImage:uiImage];
    [self.view addSubview:imageView];
    
    UIButton *pickBtn=[[UIButton alloc] initWithFrame:CGRectMake(90, 400, 100, 30)];
    pickBtn.backgroundColor=[UIColor redColor];
    [pickBtn setTitle:@"pick" forState:UIControlStateNormal];
    [pickBtn addTarget:self action:@selector(pickImage) forControlEvents:UIControlEventTouchDown];
    
    UIButton *takeBtn=[[UIButton alloc] initWithFrame:CGRectMake(210, 400, 100, 30)];
    takeBtn.backgroundColor=[UIColor redColor];
    [takeBtn setTitle:@"take" forState:UIControlStateNormal];
    [takeBtn addTarget:self action:@selector(takeImage) forControlEvents:UIControlEventTouchDown];
    
    [self.view addSubview:pickBtn];
    [self.view addSubview:takeBtn];
    
    imagePicker=[[UIImagePickerController alloc] init];
    imagePicker.modalPresentationStyle = UIModalPresentationOverCurrentContext;
    imagePicker.delegate=self;
    // Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(void) pickImage
{
    NSLog(@"pick");
    imagePicker.allowsEditing = YES;
    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    
    [self presentViewController:imagePicker animated:YES completion:^{}];
}

-(void)takeImage
{
    NSLog(@"take");
    imagePicker.allowsEditing = YES;
    if ([UIImagePickerController isSourceTypeAvailable:
         UIImagePickerControllerSourceTypeCamera])
    {
        imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
    }
    
    [self presentViewController:imagePicker animated:YES completion:^{}];
    
}

-(void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    [self dismissViewControllerAnimated:YES completion:^{}];
    
    UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];
    if (image == nil) {
        image = [info objectForKey:UIImagePickerControllerOriginalImage];
        NSLog(@"Image null");
    }
    imageView.image = image;
    NSLog(@"Photo selected");
}

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
    [self dismissViewControllerAnimated:YES completion:^{}];
    NSLog(@"Photo dimiss");
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end