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。