1. 遵守代理

<UIImagePickerControllerDelegate,UIAlertViewDelegate,UIActionSheetDelegate,UINavigationControllerDelegate>

 UIAlertController * alertVC = [UIAlertController alertControllerWithTitle:@"图片获取方式" message:@"" preferredStyle:UIAlertControllerStyleActionSheet];
    
    UIAlertAction *cameraAction = [UIAlertAction actionWithTitle:@"相机" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        //相机
        if(![XXHelper isCapturePermissionGranted]){
            NSString* info=@"没有相机权限";
            NSLog(@"%@",info);
            return;
        }
        
        if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
            UIImagePickerController * picker = [[UIImagePickerController alloc] init];
            picker.sourceType = UIImagePickerControllerSourceTypeCamera;
            picker.modalPresentationStyle = UIModalPresentationFullScreen;
            if([UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceRear]){
                picker.cameraDevice = UIImagePickerControllerCameraDeviceFront;
            }
            
            picker.mediaTypes = @[(NSString*)kUTTypeImage];
            picker.allowsEditing = YES;//设置可编辑
//创建叠加层, 可以在系统相机上层＋图片啊文字
            
            UIView *overLayView=[[UIView alloc]initWithFrame:CGRectMake( 0,44 , kScreenWidth, kScreenHeight- 164 )];
            overLayView.backgroundColor = kRandomColor;

            overLayView.alpha =0.3;
            //取景器的背景图片，该图片中间挖掉了一块变成透明，用来显示摄像头获取的图片；
            
            UIImage *overLayImag=[UIImage imageNamed:@"zhaoxiangdingwei.png"];
        
            
            UIImageView *bgImageView=[[UIImageView alloc]initWithImage:overLayImag];
            
            bgImageView.center = overLayView.center;
            [overLayView addSubview:bgImageView]; 
            
            
            picker.cameraOverlayView=overLayView;

            picker.delegate = self;
            [self presentViewController:picker animated:YES completion:nil];
        }else{
            NSLog(@"设备不可用");
        }
        
    }];
    [alertVC addAction:cameraAction];
    
    UIAlertAction *photoAction = [UIAlertAction actionWithTitle:@"相册" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        //相册
        if(![XXHelper isAssetsLibraryPermissionGranted]){
            NSString* info=@"没有相册权限";
            //            [self showAlert:info];
            NSLog(@"%@",info);
            return;
        }
        
    
        _labelView.text=@"";
        
        UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        picker.modalPresentationStyle = UIModalPresentationCurrentContext;
        if([UIImagePickerController isSourceTypeAvailable: picker.sourceType ]) {
            picker.mediaTypes = @[(NSString*)kUTTypeImage];
            picker.delegate = self;
            picker.allowsEditing = NO;
        }
        [self presentViewController:picker animated:YES completion:nil];

    }];
    [alertVC addAction:photoAction];
    alertVC.popoverPresentationController.sourceView = self.view;
    alertVC.popoverPresentationController.sourceRect = sender.frame;
    [self presentViewController:alertVC animated:YES completion:^{
        
    }];

3 .代理方法

// UIImagePickerControllerDelegate

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{ 
    UIImage* image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
    UIImage* upLoadImage = [[image fixOrientation:image] imgCompressed:image targetWidth:300];//将图片压缩成 300以上传服务器
    _imgV.image = upLoadImage;
    
    self.showImageView.image = upLoadImage;
    
    //压缩图片大小
    NSData* imgData = [upLoadImage compressedData];