iOS开发-调用系统相机和相册获取照片示例

前言：相信大家都知道大部分的app都是有我的模块的，而在我的模块基本都有用户的头像等信息，并且是可以更改头像的。那么今天小编给大家简单介绍一下ios开发中如何调用系统相机拍照或者相册获取照片。要获取系统相机或者相册，我们需要使用到 uiimagepickercontroller 这个类。下面我们来看一下如何实现：

首先，需要遵循 uiimagepickercontroller 代理的两个协议： <uiimagepickercontrollerdelegate, uinavigationcontrollerdelegate>。为什么是两个协议呢？你按着 command 键，点击 uiimagepickercontroller 的 delegate 就会发现其实这个代理遵循了两个协议。

#import "headerphotoviewcontroller.h"

@interface headerphotoviewcontroller () <uiimagepickercontrollerdelegate, uinavigationcontrollerdelegate>

@property (nonatomic, strong) uiimageview * imageview;
@end

@implementation headerphotoviewcontroller

- (void)viewdidload {
  [super viewdidload];
  self.navigationitem.title = @"设置头像";
  self.view.backgroundcolor = [uicolor whitecolor];

  [self setnavigation];
  [self addsubviews];
  [self makeconstraintsforui];
}

#pragma mark - set navigation

- (void)setnavigation {

  self.navigationitem.rightbarbuttonitem = [[uibarbuttonitem alloc] initwithbarbuttonsystemitem:uibarbuttonsystemitemcamera target:self action:@selector(selectphoto:)];
}

#pragma mark - navitation item action

- (void)selectphoto:(uibarbuttonitem *)itemcamera {

  //创建uiimagepickercontroller对象，并设置代理和可编辑
  uiimagepickercontroller * imagepicker = [[uiimagepickercontroller alloc] init];
  imagepicker.editing = yes;
  imagepicker.delegate = self;
  imagepicker.allowsediting = yes;

  //创建sheet提示框，提示选择相机还是相册
  uialertcontroller * alert = [uialertcontroller alertcontrollerwithtitle:@"请选择打开方式" message:nil preferredstyle:uialertcontrollerstyleactionsheet];

  //相机选项
  uialertaction * camera = [uialertaction actionwithtitle:@"相机" style:uialertactionstyledefault handler:^(uialertaction * _nonnull action) {

    //选择相机时，设置uiimagepickercontroller对象相关属性
    imagepicker.sourcetype = uiimagepickercontrollersourcetypecamera;
    imagepicker.modalpresentationstyle = uimodalpresentationfullscreen;
    imagepicker.mediatypes = @[(nsstring *)kuttypeimage];
    imagepicker.cameracapturemode = uiimagepickercontrollercameracapturemodephoto;
    //跳转到uiimagepickercontroller控制器弹出相机
    [self presentviewcontroller:imagepicker animated:yes completion:nil];
  }];

  //相册选项
  uialertaction * photo = [uialertaction actionwithtitle:@"相册" style:uialertactionstyledefault handler:^(uialertaction * _nonnull action) {

    //选择相册时，设置uiimagepickercontroller对象相关属性
    imagepicker.sourcetype = uiimagepickercontrollersourcetypephotolibrary;
    //跳转到uiimagepickercontroller控制器弹出相册
    [self presentviewcontroller:imagepicker animated:yes completion:nil];
  }];

  //取消按钮
  uialertaction * cancel = [uialertaction actionwithtitle:@"取消" style:uialertactionstylecancel handler:^(uialertaction * _nonnull action) {

    [self dismissviewcontrolleranimated:yes completion:nil];
  }];

  //添加各个按钮事件
  [alert addaction:camera];
  [alert addaction:photo];
  [alert addaction:cancel];

  //弹出sheet提示框
  [self presentviewcontroller:alert animated:yes completion:nil];
}

#pragma mark - add subviews

- (void)addsubviews {

  [self.view addsubview:self.imageview];
}

#pragma mark - make constraints

- (void)makeconstraintsforui {

  __weak typeof(self)weakself = self;

  [_imageview mas_makeconstraints:^(masconstraintmaker *make) {

    make.size.mas_equalto(cgsizemake(screen_width, screen_width));
    make.centerx.mas_equalto(weakself.view.mas_centerx);
    make.centery.mas_equalto(weakself.view.mas_centery);
  }];
}

#pragma mark - imagepickercontroller delegate

- (void)imagepickercontroller:(uiimagepickercontroller *)picker didfinishpickingmediawithinfo:(nsdictionary<nsstring *,id> *)info {

  [picker dismissviewcontrolleranimated:yes completion:nil];
  //获取到的图片
  uiimage * image = [info valueforkey:uiimagepickercontrollereditedimage];
  _imageview.image = image;
}

#pragma mark - setter and getter

- (uiimageview *)imageview {

  if (!_imageview) {

    _imageview = [[uiimageview alloc] init];
    _imageview.backgroundcolor = [uicolor greencolor];
    _imageview.contentmode = uiviewcontentmodescaleaspectfill;
  }
  return _imageview;
}

@end

ok！demo的所有代码都已经给大家呈现出来了，最后一步就是配置plist文件，千万不要忘了这个，要不会崩的。plist文件里边添加调用相机的字段privacy - camera usage description 和调用相册的字段：privacy - photo library usage description。万事俱备，就差一个测试的苹果手机了，相机的测试需要使用真机测试。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。