• iOS摄像头和相册-UIImagePickerController常用操作


    在一些应用中,我们需要用到iOS设备的摄像头进行拍照,视频。并且从相册中选取我们需要的图片或者视频。
    关于iOS摄像头和相册的应用,可以使用UIImagePickerController类来完成控制。
    关于UIImagePickerController的相关知识,
    如下:
     
    iOS的一些设备上都安装了摄像头。现在绝大多数都有了。
    在编程中,我们是用相应的东西来进行照相,录像等功能。
     
    一、UIImagePickerController类

    UIImagePickerController 这个类可以为大家提供照相的功能,以及图片,视频浏览的功能。 

     
    二、检查硬件是否安装有摄像头或者允许操作相册
     
    这些公共的方法,我们也许会用到,我就贴了!So easy!!!
     

    #pragma mark - 摄像头和相册相关的公共类

    // 判断设备是否有摄像头

    - (BOOL) isCameraAvailable{

        return [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera];

    }

    // 前面的摄像头是否可用

    - (BOOL) isFrontCameraAvailable{

        return [UIImagePickerControllerisCameraDeviceAvailable:UIImagePickerControllerCameraDeviceFront];

    }

    // 后面的摄像头是否可用

    - (BOOL) isRearCameraAvailable{

        return [UIImagePickerControllerisCameraDeviceAvailable:UIImagePickerControllerCameraDeviceRear];

    }

     

    // 判断是否支持某种多媒体类型:拍照,视频

    - (BOOL) cameraSupportsMedia:(NSString *)paramMediaType sourceType:(UIImagePickerControllerSourceType)paramSourceType{

        __block BOOL result = NO;

        if ([paramMediaType length] == 0){

            NSLog(@"Media type is empty.");

            return NO;

        }

        NSArray *availableMediaTypes =[UIImagePickerControlleravailableMediaTypesForSourceType:paramSourceType];

        [availableMediaTypes enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL*stop) {

                                                            NSString *mediaType = (NSString *)obj;

                                                            if ([mediaTypeisEqualToString:paramMediaType]){

                                                               result = YES;

                                                               *stop= YES;

                                                            }

            

        }];

        return result;

    }

    // 检查摄像头是否支持录像

    - (BOOL) doesCameraSupportShootingVideos{

        return [self cameraSupportsMedia:( NSString *)kUTTypeMoviesourceType:UIImagePickerControllerSourceTypeCamera];

    }

    // 检查摄像头是否支持拍照

    - (BOOL) doesCameraSupportTakingPhotos{

        return [self cameraSupportsMedia:( NSString *)kUTTypeImagesourceType:UIImagePickerControllerSourceTypeCamera];

    }

     

    #pragma mark - 相册文件选取相关

    // 相册是否可用

    - (BOOL) isPhotoLibraryAvailable{

        return [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary];

    }

    // 是否可以在相册中选择视频

    - (BOOL) canUserPickVideosFromPhotoLibrary{

        return [self cameraSupportsMedia:( NSString *)kUTTypeMoviesourceType:UIImagePickerControllerSourceTypePhotoLibrary];

    }

    // 是否可以在相册中选择视频

    - (BOOL) canUserPickPhotosFromPhotoLibrary{

        return [self cameraSupportsMedia:( NSString *)kUTTypeImagesourceType:UIImagePickerControllerSourceTypePhotoLibrary];

    }

     
    三、用摄像头进行拍照和录像功能
     
    1.我们将UIImagePickerController功能写在一个按钮的点击事件中:
     

    #pragma mark - 拍照按钮事件

    - (void)ClickControlAction:(id)sender{

        // 判断有摄像头,并且支持拍照功能

        if ([self isCameraAvailable] && [self doesCameraSupportTakingPhotos]){

            // 初始化图片选择控制器

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

            [controller setSourceType:UIImagePickerControllerSourceTypeCamera];// 设置类型

            

            // 设置所支持的类型,设置只能拍照,或则只能录像,或者两者都可以

            NSString *requiredMediaType = ( NSString *)kUTTypeImage;

            NSString *requiredMediaType1 = ( NSString *)kUTTypeMovie;

            NSArray *arrMediaTypes=[NSArray arrayWithObjects:requiredMediaType, requiredMediaType1,nil];

            [controller setMediaTypes:arrMediaTypes];

            

            // 设置录制视频的质量

            [controller setVideoQuality:UIImagePickerControllerQualityTypeHigh];

            //设置最长摄像时间

            [controller setVideoMaximumDuration:10.f];

            

            [controller setAllowsEditing:YES];// 设置是否可以管理已经存在的图片或者视频

            [controller setDelegate:self];// 设置代理

            [self.navigationController presentModalViewController:controller animated:YES];

            [controller release];

        } else {

            NSLog(@"Camera is not available.");

        }

    }

     
     
    解释:
     
    2. setSourceType方法
     
    通过设置setSourceType方法可以确定调用出来的UIImagePickerController所显示出来的界面
     

    typedef NS_ENUM(NSInteger, UIImagePickerControllerSourceType) {

        UIImagePickerControllerSourceTypePhotoLibrary,

        UIImagePickerControllerSourceTypeCamera,

        UIImagePickerControllerSourceTypeSavedPhotosAlbum

    };

     
    分别表示:图片列表,摄像头,相机相册
     
    3.setMediaTypes方法
     

    // 设置所支持的类型,设置只能拍照,或则只能录像,或者两者都可以

            NSString *requiredMediaType = ( NSString *)kUTTypeImage;

            NSString *requiredMediaType1 = ( NSString *)kUTTypeMovie;

            NSArray *arrMediaTypes=[NSArray arrayWithObjects:requiredMediaType, requiredMediaType1,nil];

            [controller setMediaTypes:arrMediaTypes];

     
     
    4.关于UIImagePickerControllerDelegate协议
     
    我们要对我们拍摄的照片和视频进行存储,那么就要实现UIImagePickerControllerDelegate协议的方法。
     

    #pragma mark - UIImagePickerControllerDelegate 代理方法

    // 保存图片后到相册后,调用的相关方法,查看是否保存成功

    - (void) imageWasSavedSuccessfully:(UIImage *)paramImage didFinishSavingWithError:(NSError *)paramError contextInfo:(void *)paramContextInfo{

        if (paramError == nil){

            NSLog(@"Image was saved successfully.");

        } else {

            NSLog(@"An error happened while saving the image.");

            NSLog(@"Error = %@", paramError);

        }

    }

    // 当得到照片或者视频后,调用该方法

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

        NSLog(@"Picker returned successfully.");

        NSLog(@"%@", info);

        NSString *mediaType = [infoobjectForKey:UIImagePickerControllerMediaType];

        // 判断获取类型:图片

        if ([mediaType isEqualToString:( NSString *)kUTTypeImage]){

            UIImage *theImage = nil;

            // 判断,图片是否允许修改

            if ([picker allowsEditing]){

                //获取用户编辑之后的图像

                theImage = [infoobjectForKey:UIImagePickerControllerEditedImage];

            } else {

                // 照片的元数据参数

                theImage = [infoobjectForKey:UIImagePickerControllerOriginalImage];

                

            }

            

            // 保存图片到相册中

            SEL selectorToCall = @selector(imageWasSavedSuccessfully:didFinishSavingWithError:contextInfo:);

            UIImageWriteToSavedPhotosAlbum(theImage,self,selectorToCall, NULL);

            

        }else if ([mediaType isEqualToString:(NSString*)kUTTypeMovie]){

            // 判断获取类型:视频

            //获取视频文件的url

            NSURL* mediaURL = [infoobjectForKey:UIImagePickerControllerMediaURL];

            //创建ALAssetsLibrary对象并将视频保存到媒体库

            // Assets Library 框架包是提供了在应用程序中操作图片和视频的相关功能。相当于一个桥梁,链接了应用程序和多媒体文件。

            ALAssetsLibrary *assetsLibrary = [[ALAssetsLibraryalloc] init];

            // 将视频保存到相册中

            [assetsLibrary writeVideoAtPathToSavedPhotosAlbum:mediaURL

                                             completionBlock:^(NSURL *assetURL, NSError *error) {

                                                  if (!error) {

                                                     NSLog(@"captured video saved with no error.");

                                                  }else{

                                                      NSLog(@"error occured while saving the video:%@", error);

                                                  }

                                              }];

            [assetsLibrary release];

        

        

        }

        

        

        [picker dismissModalViewControllerAnimated:YES];

    }

    // 当用户取消时,调用该方法

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

        

        [picker dismissModalViewControllerAnimated:YES];

    }

     
    四、从相册获取图片和视频数据
     
    1.我们将功能封装在一个按钮的点击事件中
     

    #pragma mark - 相册操作

    - (void)ClickShowPhotoAction:(id)sender{

        

        if ([self isPhotoLibraryAvailable]){

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

             [controller setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];// 设置类型

            NSMutableArray *mediaTypes = [[NSMutableArray alloc] init];

            if ([self canUserPickPhotosFromPhotoLibrary]){

                [mediaTypes addObject:( NSString *)kUTTypeImage];

            }

            if ([self canUserPickVideosFromPhotoLibrary]){

                [mediaTypes addObject:( NSString *)kUTTypeMovie];

            }

            

            [controller setMediaTypes:mediaTypes];

            [controller setDelegate:self];// 设置代理

            [self.navigationController presentModalViewController:controller animated:YES];

            [controller release];

            [mediaTypes release];

            

        }

    }

     
    2.关于UIImagePickerControllerDelegate协议,我们可以重用。
     
    在这里,就不用赘述了!
     
    最后,需要说的是,UIImagePickerControllerDelegate协议中

    -(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info方法,中的info值,会根据我们操作的类型不同,而产生了不同的数据信息:

    当操作的为图片时::

    {

        UIImagePickerControllerCropRect = "NSRect: {{0, 405}, {2448, 2449}}";

        UIImagePickerControllerEditedImage = "";

        UIImagePickerControllerMediaMetadata =     {

            DPIHeight = 72;

            DPIWidth = 72;

            Orientation = 6;

            "{Exif}" =         {

                ApertureValue = "2.526068811667588";

                BrightnessValue = "-0.0709875088566263";

                ColorSpace = 1;

                DateTimeDigitized = "2013:04:05 16:43:00";

                DateTimeOriginal = "2013:04:05 16:43:00";

                ExposureMode = 0;

                ExposureProgram = 2;

                ExposureTime = "0.05882352941176471";

                FNumber = "2.4";

                Flash = 24;

                FocalLenIn35mmFilm = 35;

                FocalLength = "4.28";

                ISOSpeedRatings =             (

                    400

                );

                MeteringMode = 5;

                PixelXDimension = 3264;

                PixelYDimension = 2448;

                SceneType = 1;

                SensingMethod = 2;

                Sharpness = 0;

                ShutterSpeedValue = "4.099543917546131";

                SubjectArea =             (

                    1631,

                    1223,

                    881,

                    881

                );

                WhiteBalance = 0;

            };

            "{TIFF}" =         {

                DateTime = "2013:04:05 16:43:00";

                Make = Apple;

                Model = "iPhone 4S";

                Software = "5.1.1";

                XResolution = 72;

                YResolution = 72;

            };

        };

        UIImagePickerControllerMediaType = "public.image";

        UIImagePickerControllerOriginalImage = "";

    }

     
    当我们操作的为视频时:
     

    {

        UIImagePickerControllerMediaType = "public.movie";

        UIImagePickerControllerMediaURL = "file://localhost/private/var/mobile/Applications/22A14825-DD7E-48E1-A1D5-2D85B82095B5/tmp/capture-T0x1363a0.tmp.etXfD4/capturedvideo.MOV";

    }

     
     
    选择资源以后获取资源路径:

    - (void) pickImage: (id) sender

    {

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

            if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]){

         ipc.sourceType =  UIImagePickerControllerSourceTypePhotoLibrary;

          ipc.mediaTypes =[UIImagePickerController availableMediaTypesForSourceType:ipc.sourceType];   

            }  

    ipc.delegate = self;

    ipc.allowsImageEditing = NO;

    [self presentModalViewController:ipc animated:YES];

    }

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

    NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];

    if ([mediaType isEqualToString:@"public.image"]){

    //UIImage *selectedImage = [info objectForKey:UIImagePickerControllerOriginalImage];

    UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];

        NSLog(@"found an image");

    [UIImageJPEGRepresentation(image, 1.0f) writeToFile:[self findUniqueSavePath] atomically:YES];

        SETIMAGE(image);

    CFShow([[NSFileManager defaultManager] directoryContentsAtPath:[NSHomeDirectory() stringByAppendingString:@"/Documents"]]);

    }

    else if ([mediaType isEqualToString:@"public.movie"]){

    NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];

    NSLog(@"found a video");

            NSData *webData = [NSData dataWithContentsOfURL:videoURL];

    //NSData *video = [[NSString alloc] initWithContentsOfURL:videoURL];

    [webData writeToFile:[self findUniqueMoviePath] atomically:YES];

    CFShow([[NSFileManager defaultManager] directoryContentsAtPath:[NSHomeDirectory() stringByAppendingString:@"/Documents"]]);

    //NSLog(videoURL);

    }

    [picker dismissModalViewControllerAnimated:YES];

    }

    摘自:http://blog.sina.com.cn/s/blog_7b9d64af0101cfd9.html  感谢博主分享
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  • 原文地址:https://www.cnblogs.com/cy568searchx/p/5808253.html
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