1.相机的调用

• 要打开系统的相机要在调用相册的类里循序两个协议，分别是UIImagePickerControllerDelegate 和 UINavigationControllerDelegate。首先要有一个全局的UIImagePickerController变量类，主要是通过重写它的setter方法设置这个类的的成员变量或者是属性值，然后执行这两个协议的回调方法，主要的回调方法有三个，拍照时回调方法，拍照取消是的回调方法，将在下面得到简单的体现。

@interface HHMyMessageViewController () <UITableViewDelegate,UITableViewDataSource,UIImagePickerControllerDelegate,UINavigationControllerDelegate> 
/**
 *  切换到相机的管理器
 */
@property (nonatomic,strong) UIImagePickerController *imagePicker;
/**
 *   照片展示视图
 */
@property (nonatomic,strong) UIImageView *_headImage;
@end
@implementation HHMyMessageViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self setMessageOfPersonal];
}
- (void)setMessageOfPersonal {
_headImage = [[UIImageView alloc] init];
    UIButton *takeButton = [UIButton buttonWithType:UIButtonTypeCustom];
    [self.view addSubview:takeButton];
    [takeButton addTarget:self action:@selector(takeClick:) forControlEvents:UIControlEventTouchDown];
}
/**
 *  拍照的回调方法
 *
 *  @param sender 点击按钮
 */
- (void)takeClick:(UIButton *)sender {
    [self presentViewController:self.imagePicker animated:YES completion:nil];
}

#pragma mark - UIImagePickerController代理方法
// 完成拍照后的回调方法
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
    NSString *mediaType=[info objectForKey:UIImagePickerControllerMediaType];
     // 如果是拍照
    if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
        UIImage *image;
        // 如果允许编辑则获得编辑后的照片，否则获取原始照片
        if (self.imagePicker.allowsEditing) {
            // 获取编辑后的照片
            image = [info objectForKey:UIImagePickerControllerEditedImage];
        }
        else{
            // 获取原始照片
            image = [info objectForKey:UIImagePickerControllerOriginalImage];
        }
        NSUserDefaults *def = [NSUserDefaults standardUserDefaults];
        [def setObject:data1 forKey:@"headimage"];
        [def synchronize];
        // 显示照片
        _headImage.image = [UIImage imageWithData:data1];
        if (image) {
            self.myImage(image);
        }
        // 保存到相簿
//        UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
    }
    [self dismissViewControllerAnimated:YES completion:nil];
}

/**
 *  点击相册取消按钮的回调方法
 *
 *  @param picker 取消按钮
 */
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
    
    [self.imagePicker dismissViewControllerAnimated:YES completion:nil];
}

#pragma mark - 重写imagePicker的geter方法
- (UIImagePickerController *)imagePicker{
    if (!_imagePicker) {
        _imagePicker = [[UIImagePickerController alloc]init];
        // 判断现在可以获得多媒体的方式
        if ([UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera]) {
            // 设置image picker的来源，这里设置为摄像头
            _imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
            // 设置使用哪个摄像头，这里默认设置为前置摄像头
            _imagePicker.cameraDevice = UIImagePickerControllerCameraDeviceFront;
            if (self.isVideo) {
                _imagePicker.mediaTypes = @[(NSString *)kUTTypeMovie];
                _imagePicker.videoQuality = UIImagePickerControllerQualityTypeIFrame1280x720;
                // 设置摄像头模式（拍照，录制视频）
                _imagePicker.cameraCaptureMode = UIImagePickerControllerCameraCaptureModeVideo;
            }
            else{
                // 设置摄像头模式为照相
                _imagePicker.cameraCaptureMode = UIImagePickerControllerCameraCaptureModePhoto;
            }
        }
        else {
            _imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        }
        // 允许编辑
        _imagePicker.allowsEditing=YES;
        // 设置代理，检测操作
        _imagePicker.delegate=self;
    }
    return _imagePicker;
}