iOS开发图片选择

一行代码搞定图片选择

//
//  gzhPhotoManager.h
//  图片选择
//
//  Created by 郭志贺 on 2020/5/26.
//  Copyright © 2020 郭志贺. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "ViewController.h"

NS_ASSUME_NONNULL_BEGIN
@protocol gzhPhotoManagerDelegate;
@interface gzhPhotoManager : NSObject

+(instancetype)instance;

/// 选择图片
/// @param controller 当前控制器
/// @param target 代理
/// @param pSize 选择照片尺寸 尺寸传（0，0）不进行裁剪
- (void)selectPhotoWithController:(UIViewController *)controller delegate:(id)target size:(CGSize)pSize;

@end

@protocol gzhPhotoManagerDelegate <NSObject>

- (void)selectedPhotoImage:(UIImage *)image;

@end
NS_ASSUME_NONNULL_END

 //
 //  gzhPhotoManager.m
 //  图片选择
 //
 //  Created by 郭志贺 on 2020/5/26.
 //  Copyright © 2020 郭志贺. All rights reserved.
 //

 #import "gzhPhotoManager.h"
 #import <MobileCoreServices/MobileCoreServices.h>
 #import <Photos/Photos.h>
 #import <AssetsLibrary/AssetsLibrary.h>
 #import <MetalPerformanceShaders/MetalPerformanceShaders.h>

 @interface gzhPhotoManager () <UINavigationControllerDelegate,UIImagePickerControllerDelegate>

 @property (nonatomic, weak) id<gzhPhotoManagerDelegate> delegate;
 @property (nonatomic, assign) CGSize photoSize;
 @property (nonatomic, strong) UIImage *image;
 @property (nonatomic, weak) UIViewController *controller;
 @property (nonatomic, strong) UIImagePickerController *imagePickerController;

 @end

 @implementation gzhPhotoManager

 + (instancetype)instance {
     static gzhPhotoManager * shareInstance = nil;
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
         shareInstance = [[gzhPhotoManager alloc]init];
     });
     return shareInstance;
 }
 -(void)selectPhotoWithController:(UIViewController *)controller delegate:(id)target size:(CGSize)pSize{

     _controller = controller;
     _delegate = target;
     _photoSize = pSize;

     UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:UIAlertControllerStyleActionSheet];
     [alertVC addAction:[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil]];
     [alertVC addAction:[UIAlertAction actionWithTitle:@"拍照" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

         [self cameraCheck:action];
     }]];
     [alertVC addAction:[UIAlertAction actionWithTitle:@"从手机相册中选择" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

         [self phAuthorizationCheck:action];
     }]];
     [_controller presentViewController:alertVC animated:YES completion:nil];
 }
 -(void)cameraCheck:(UIAlertAction *)action{
     /*
      AVAuthorizationStatusNotDetermined = 0,// 系统还未知是否访问，第一次开启相机时

      AVAuthorizationStatusRestricted, // 受限制的

      AVAuthorizationStatusDenied, //不允许

      AVAuthorizationStatusAuthorized // 允许状态
      */

     ALAuthorizationStatus author =[ALAssetsLibrary authorizationStatus];
     if (author == AVAuthorizationStatusRestricted || author ==AVAuthorizationStatusDenied) {
         [self alertViewWithTitle:@"提示" message:@"如需拍照,请检查拍照功能是否开启,可在:设置->隐私->照相.设置"];
     }else if (author == AVAuthorizationStatusAuthorized){
         [self selectCamera:action];
     }else if (author == AVAuthorizationStatusNotDetermined){
         [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {

             if (granted) {

                 //允许访问
                 [self selectCamera:action];
             }else{

                 //不允许访问
                 [self alertViewWithTitle:@"提示" message:@"如需拍照,请检查拍照功能是否开启,可在:设置->隐私->照相.设置"];
             }

         }];
     }

 }

 //判断是否有权限访问相簿
 - (void)phAuthorizationCheck:(UIAlertAction *)action{
     /*
      PHAuthorizationStatusNotDetermined,     用户还没有做出选择
      PHAuthorizationStatusDenied,            用户拒绝当前应用访问相册(用户当初点击了"不允许")
      PHAuthorizationStatusAuthorized         用户允许当前应用访问相册(用户当初点击了"好")
      PHAuthorizationStatusRestricted,        因为家长控制, 导致应用无法方法相册(跟用户的选择没有关系)
      */

     // 判断授权状态
     PHAuthorizationStatus statu = [PHPhotoLibrary authorizationStatus];
     if (statu == PHAuthorizationStatusRestricted) {
         NSLog(@"无法访问相簿--PHAuthorizationStatusRestricted");
         [self alertViewWithTitle:@"提示" message:@"如需拍照,请检查拍照功能是否开启,可在:设置->隐私->照片.设置"];
     } else if (statu == PHAuthorizationStatusDenied) {
         NSLog(@"无法访问相簿--PHAuthorizationStatusDenied");
         [self alertViewWithTitle:@"提示" message:@"如需拍照,请检查拍照功能是否开启,可在:设置->隐私->照片.设置"];
     } else if (statu == PHAuthorizationStatusAuthorized) {
         NSLog(@"可以访问相簿--PHAuthorizationStatusAuthorized");
         [self selectPhotoLibrary:action];
     } else if (statu == PHAuthorizationStatusNotDetermined) {
         // 弹框请求用户授权
         NSLog(@"第一次访问--PHAuthorizationStatusNotDetermined");
         [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {

             if (status == PHAuthorizationStatusAuthorized) {
                 [self selectPhotoLibrary:action];
             }else{
                 [self alertViewWithTitle:@"提示" message:@"如需拍照,请检查拍照功能是否开启,可在:设置->隐私->照片.设置"];
             }

         }];

     }

 }
 // 拍照
 - (void)selectCamera:(UIAlertAction *)action {
     if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
         dispatch_async(dispatch_get_main_queue(), ^{
             [self alertViewWithTitle:@"警告" message:@"对不起,您的设备不存在相机"];
         });

         return;
     }

     if (!_imagePickerController) {
         _imagePickerController = [UIImagePickerController new];
         _imagePickerController.delegate = self;
     }
     if (_photoSize.width!=&&_photoSize.height!=) {
         _imagePickerController.allowsEditing = YES;
     }else{
         _imagePickerController.allowsEditing = NO;
     }

     _imagePickerController.mediaTypes = @[(NSString *)kUTTypeImage];
     _imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
     _imagePickerController.cameraCaptureMode = UIImagePickerControllerCameraCaptureModePhoto;
     [_controller presentViewController:_imagePickerController animated:YES completion:nil];
 }

 // 从相册中选择
 - (void)selectPhotoLibrary:(UIAlertAction *)action {
     if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
         dispatch_async(dispatch_get_main_queue(), ^{
              [self alertViewWithTitle:@"警告" message:@"对不起，您的设备不存在相册"];
         });

     }
     if (!_imagePickerController) {
         _imagePickerController = [UIImagePickerController new];
         _imagePickerController.delegate = self;
     }
     if (_photoSize.width!=&&_photoSize.height!=) {
         _imagePickerController.allowsEditing = YES;
     }else{
         _imagePickerController.allowsEditing = NO;
     }
     _imagePickerController.mediaTypes = @[(NSString *)kUTTypeImage,(NSString *)kUTTypeMovie];
     _imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
     [_controller presentViewController:_imagePickerController animated:YES completion:nil];

 }
 #pragma mark -
 #pragma mark - UIImagePickerViewController delegate
 - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

     NSString * mediaType = [info objectForKey:UIImagePickerControllerMediaType];
     if ([mediaType isEqualToString:(NSString *)kUTTypeImage]){
         if (_photoSize.height!=&&_photoSize.width!=) {
             UIImage *image = [self fixOrientation:[info objectForKey:UIImagePickerControllerEditedImage]];
             self.image = [self scaleImage:image Tosize:self.photoSize];
             if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) {
                 UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
             }
         }else{
             UIImage *image = [self fixOrientation:[info objectForKey:UIImagePickerControllerOriginalImage]];
             self.image = [self scaleImage:image Tosize:self.photoSize];
             if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) {
                 UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
             }
         }
         [picker dismissViewControllerAnimated:YES completion:^{
             if (self.delegate && [self.delegate respondsToSelector:@selector(selectedPhotoImage:)]) {
                 if (self.image) {
                     [self.delegate selectedPhotoImage:self.image];
                 } else {
                     [self alertViewWithTitle:@"你还没选择图片呢" message:nil];
                 }
             }
         }];
     }

 }

 -(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
     [picker dismissViewControllerAnimated:YES completion:nil];
 }
 // 裁剪图片
 - (UIImage *)scaleImage:(UIImage *)img Tosize:(CGSize)size {

     CGFloat screenWidth = [UIScreen mainScreen].bounds.size.width;
     CGSize imgSize = CGSizeMake(, );
     if (size.width !=  && size.height != ) {
         imgSize = CGSizeMake(size.width, img.size.height*(size.width/img.size.width));
     } else {
         imgSize = CGSizeMake(screenWidth*, img.size.height*(screenWidth/img.size.width)*);
     }
     // 创建一个bitmap的context
     // 并把它设置成为当前正在使用的context
     UIGraphicsBeginImageContext(imgSize);
     // 绘制改变大小的图片
     [img drawInRect:CGRectMake(, , imgSize.width, imgSize.height)];
     // 从当前context中创建一个改变大小后的图片
     UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
     // 使当前的context出堆栈
     UIGraphicsEndImageContext();
     //返回新的改变大小后的图片
     return scaledImage;
 }

 //修正image方向
 - (UIImage *)fixOrientation:(UIImage *)aImage {

     if (aImage.imageOrientation == UIImageOrientationUp)
         return aImage;

     CGAffineTransform transform = CGAffineTransformIdentity;

     switch (aImage.imageOrientation) {
         case UIImageOrientationDown:
         case UIImageOrientationDownMirrored:
             transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height);
             transform = CGAffineTransformRotate(transform, M_PI);
             break;

         case UIImageOrientationLeft:
         case UIImageOrientationLeftMirrored:
             transform = CGAffineTransformTranslate(transform, aImage.size.width, );
             transform = CGAffineTransformRotate(transform, M_PI_2);
             break;

         case UIImageOrientationRight:
         case UIImageOrientationRightMirrored:
             transform = CGAffineTransformTranslate(transform, , aImage.size.height);
             transform = CGAffineTransformRotate(transform, -M_PI_2);
             break;
         default:
             break;
     }

     switch (aImage.imageOrientation) {
         case UIImageOrientationUpMirrored:
         case UIImageOrientationDownMirrored:
             transform = CGAffineTransformTranslate(transform, aImage.size.width, );
             transform = CGAffineTransformScale(transform, -, );
             break;

         case UIImageOrientationLeftMirrored:
         case UIImageOrientationRightMirrored:
             transform = CGAffineTransformTranslate(transform, aImage.size.height, );
             transform = CGAffineTransformScale(transform, -, );
             break;
         default:
             break;
     }

     CGContextRef ctx = CGBitmapContextCreate(NULL, aImage.size.width, aImage.size.height,
                                              CGImageGetBitsPerComponent(aImage.CGImage), ,
                                              CGImageGetColorSpace(aImage.CGImage),
                                              CGImageGetBitmapInfo(aImage.CGImage));
     CGContextConcatCTM(ctx, transform);
     switch (aImage.imageOrientation) {
         case UIImageOrientationLeft:
         case UIImageOrientationLeftMirrored:
         case UIImageOrientationRight:
         case UIImageOrientationRightMirrored:
             // Grr...
             CGContextDrawImage(ctx, CGRectMake(,,aImage.size.height,aImage.size.width), aImage.CGImage);
             break;

         default:
             CGContextDrawImage(ctx, CGRectMake(,,aImage.size.width,aImage.size.height), aImage.CGImage);
             break;
     }

     // And now we just create a new UIImage from the drawing context
     CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
     UIImage *img = [UIImage imageWithCGImage:cgimg];
     CGContextRelease(ctx);
     CGImageRelease(cgimg);
     return img;
 }

 // 提醒
 - (void)alertViewWithTitle:(NSString *)title message:(NSString *)msg {
     UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:title message:msg preferredStyle:UIAlertControllerStyleAlert];
     [alertVC addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleCancel handler:nil]];
     [_controller presentViewController:alertVC animated:YES completion:nil];
 }

 @end

在需要使用的地方遵循<gzhPhotoManagerDelegate>协议

 //
 //  ViewController.m
 //  图片选择
 //
 //  Created by 郭志贺 on 2020/5/26.
 //  Copyright © 2020 郭志贺. All rights reserved.
 //

 #import "ViewController.h"
 #import "gzhPhotoManager.h"

 /** 屏幕高度 */
 #define ScreenH [UIScreen mainScreen].bounds.size.height
 /** 屏幕宽度 */
 #define ScreenW [UIScreen mainScreen].bounds.size.width

 @interface ViewController ()<gzhPhotoManagerDelegate>
 @property(nonatomic,strong)UIImageView * selectImageView;
 @end

 @implementation ViewController

 - (void)viewDidLoad {
     [super viewDidLoad];
     // Do any additional setup after loading the view.

     _selectImageView = [[UIImageView alloc]init];
     _selectImageView.frame = CGRectMake(, , ScreenW, ScreenH);
     _selectImageView.contentMode = UIViewContentModeScaleAspectFit;
     _selectImageView.clipsToBounds = YES;
     _selectImageView.backgroundColor = [UIColor purpleColor];
     [self.view addSubview:_selectImageView];

     _selectImageView.userInteractionEnabled = YES;
     UITapGestureRecognizer * selectPhotoTapGes = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(selectPhoto:)];
     [_selectImageView addGestureRecognizer:selectPhotoTapGes];

 }
 -(void)selectPhoto:(UITapGestureRecognizer *)taps{
     //调用
     [[gzhPhotoManager instance]selectPhotoWithController:self delegate:self size:CGSizeMake(ScreenW, ScreenW)];

 }
 -(void)selectedPhotoImage:(UIImage *)image{

     _selectImageView.image = image;

 }
 @end

可直接复制使用，新手见解，如有遗漏或不足敬请告知。