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;
//设置是否可编辑
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;
}
@endOK！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。
最后，希望能够帮助到有需要的猿友们，愿同是程序猿的我们能够共同学习进步，在开发的道路上越走越远！谢谢！
拓展：如果想要识别选择图片的二维码，需要在代理中进行修改，具体代码如下
- (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];
// 2、创建 CIImage
CIImage *ciimage = [[CIImage alloc] initWithImage:image];
// 3、识别精度
NSDictionary *options = @{CIDetectorAccuracy: CIDetectorAccuracyHigh};
// 4、创建识别器
CIDetector *detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:nil options:options];
NSArray *features = [detector featuresInImage:ciimage];
NSString *message = nil;
for (CIFeature *item in features) {
if ([item isKindOfClass:[CIQRCodeFeature class]]) {
message = [(CIQRCodeFeature *)item messageString];
NSLog(@"message = %@", message);
break;
}
}
}设置是否能编辑图片
BOOL allowsEditing
设置当拍照完或在相册选完照片后，是否跳到编辑模式进行图片剪裁即是否允许编辑
showsCameraControls=Yes时才有效果。
[imagePicker setAllowsEditing:YES];
取消编辑的话要将其置为NO，同时获取到的图片类型要修改为UIImagePickerControllerOriginalImage
[imagePicker setAllowsEditing:NO];
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UIImage * image = [info valueForKey:UIImagePickerControllerOriginalImage];
参考：iOS开发-调用系统相机和相册获取照片 - 简书ios基础篇（一）—— UIImagePickerController类_一颗程序媛0915的博客-CSDN博客