iOS中 读取相册,调用系统相机 技术分享

技术内容：分别读取相册以及调取相机,将图片显示到imageView上

布局：

1.创建imageView 和 button 并为button一个关联pickerImage的事件

<div style="text-align: left;"><span style="font-family: Helvetica; -webkit-text-stroke-width: initial;">    self.aImageView = [[UIImageView alloc]initWithFrame:CGRectMake(60, 100, 200, 200)];</span></div>    self.aImageView.backgroundColor = [UIColor redColor];    self.aImageView.userInteractionEnabled = YES;        self.aButton = [[UIButton alloc]initWithFrame:CGRectMake(98, 350, 125, 25)];    self.aButton.backgroundColor = [UIColor blueColor];    [self.aButton addTarget:self action:@selector(pickerImage:) forControlEvents:(UIControlEventTouchUpInside)];    [self.aButton setTitle:@"选择图像" forState:(UIControlStateNormal)];        [self.view addSubview:self.aButton];    [self.view addSubview:self.aImageView];    [self.aButton release];    [self.aImageView release];            [self addTapGestureOnImageView];

2.因为有的场景需要直接点击图片更换别的图片，所以在imageView上添加轻拍动作

- (void)addTapGestureOnImageView{    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(pickerImage:)];    [self.aImageView addGestureRecognizer:tap];    [tap release];}

3.实现轻拍动作中方法

- (void)pickerImage:(UIButton *)button{    //添加ActionSheet控件，提示选项框，调出相机或拍摄图片    //第一个参数：是行为列表的标题 一般为空    //第二个参数：遵循代理    //第三个参数：取消这个操作按钮上 显示的文字    //第四个参数：destructive 破坏性的, 毁灭性的 自己理解吧 反正我写的是拍照，执行操作的意思    //第五个参数：从相册选取图片    UIActionSheet *actionSheet = [[UIActionSheet alloc]initWithTitle:nil delegate:self cancelButtonTitle:@"取消" destructiveButtonTitle:@"拍照" otherButtonTitles:@"从相册选择图片", nil];    //在当前界面显示actionSheet对象    [actionSheet showInView:self.view];    [actionSheet release];}

4.实现action代理协议中的方法

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{    switch (buttonIndex) {        case 0:            //调用系统相机，拍照            [self pickerPictureFromCamera];            break;        case 1:            [self pickerPictureFromPhotosAlbum];        default:            break;    }}

4.1从摄像头获取图片

- (void)pickerPictureFromCamera{        //判断前摄像头是否可用，如果不可用的话，用后摄像头。如果后摄像头也不可用的话用手机图片库    //判断前置摄像头是否可用    if ([UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceFront]) {        NSLog(@"用前置摄像头");                self.imagePC = [[UIImagePickerController alloc]init];        self.imagePC.cameraDevice = UIImagePickerControllerCameraDeviceFront;        [self.imagePC release];        //判断后置摄像头是否可用    }else if ([UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceRear]){        NSLog(@"用后置摄像头");                self.imagePC = [[UIImagePickerController alloc]init];        self.imagePC.cameraDevice = UIImagePickerControllerCameraDeviceRear;        [self.imagePC release];        //两者都不行的话，从手机相册调取照片    }else{        UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"调用摄像头失败" message:@"请从手机相册中选取照片" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];        [alertView show];        [alertView release];    }        //初始化图片控制器对象    UIImagePickerController *imagePicker = [[UIImagePickerController alloc]init];    //sourceType资源样式    //设置图片选择器选择图片的样式    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;    //设置图片是否允许编辑    imagePicker.allowsEditing = YES;    //设置图片选择器代理对象为这个视图控制器    imagePicker.delegate = self;    //把相机推出来 模态    [self presentViewController:imagePicker animated:YES completion:nil];    //释放    [imagePicker release];    }

4.2从手机的图片库获取图片

- (void)pickerPictureFromPhotosAlbum{    //初始化图片控制器对象    UIImagePickerController *imagePicker = [[UIImagePickerController alloc]init];    //sourceType资源样式    //设置图片选择器选择图片的样式    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;    //设置图片是否允许编辑    imagePicker.allowsEditing = YES;    //设置图片选择器代理对象为这个视图控制器    imagePicker.delegate = self;    //把选择控制器推出来 模态    [self presentViewController:imagePicker animated:YES completion:nil];    //释放    [imagePicker release];}

5.将选取好的照片保存到详情页的方法

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{    //以相册作为字典，从中取出照片    self.aImageView.image = [info objectForKey:UIImagePickerControllerEditedImage];    //把选取框模态回去    [self dismissViewControllerAnimated:YES completion:nil];}

测试效果：（由于mac端虚拟机无前后摄像头所以直接跳转相册选取）