iPhone和iPad调用系统相册

iOS中，iPhone和iPad调用系统的方法不相同，需要区分判断，否则会崩溃，错误提示如下：

Warning: Error creating LLDB target at path 'xxx'- using an empty LLDB target which can cause slow memory reads from remote devices.

1.我们可以使用系统的UI_USER_INTERFACE_IDIOM()去判断获取设备的类型，如下：

//iPhone设备
UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone
//ipad设备
UI_USER_INTERFACE_IDIOM()== UIUserInterfaceIdiomPad

2.在视图控制器上，iPhone使用UIImagePickerController图像选取器来调用系统相册，iPad则需使用UIPopoverController视图控制器

//iPhone
UIImagePickerController *picker;
//iPad
UIPopoverController *imagePicker;

完整示例代码

1.首先在.pch文件定义一个宏用于判断是什么类型设备（根据自身需要决定）

//iPhone设备
#define IS_IPHONE (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
//iPad设备
#define IS_PAD (UI_USER_INTERFACE_IDIOM()== UIUserInterfaceIdiomPad)

2.在调用的VC文件中

//添加代理
<UIImagePickerControllerDelegate,UINavigationControllerDelegate>
//声明函数
//iPhone
@property (strong, nonatomic) UIImagePickerController *picker;
//iPad
@property (nonatomic, retain) UIPopoverController *imagePicker;
//调用相册方法
-(void)getPhotoMethod
{
    if (IS_IPHONE) {
        NSLog(@"iPhone调用相册");
        self.picker = [[UIImagePickerController alloc] init];
        self.picker.delegate = self;
        self.picker.allowsEditing = YES;
        UIAlertController *actionSheet = [UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:UIAlertControllerStyleActionSheet];
        UIAlertAction *cameraAction = [UIAlertAction actionWithTitle:@"从相机拍照" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action){
            if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]){
                self.picker.sourceType = UIImagePickerControllerSourceTypeCamera;
                [self presentViewController:self.picker animated:YES completion:nil];
            }
        }];
        UIAlertAction *photoAction = [UIAlertAction actionWithTitle:@"从相册选择" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            self.picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
            [self presentViewController:self.picker animated:YES completion:nil];
        }];
        UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:Localized(@"pr_key_16") style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
            NSLog(@"取消");
        }];
        [actionSheet addAction:cameraAction];
        [actionSheet addAction:photoAction];
        [actionSheet addAction:cancelAction];
        [self presentViewController:actionSheet animated:YES completion:nil];
    }else{
        NSLog(@"ipad调用相册");
        UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        //是否允许编辑
        picker.allowsEditing = NO;
        picker.sourceType = sourceType;
        UIPopoverController *popover = [[UIPopoverController alloc]initWithContentViewController:picker];
        self.imagePicker = popover;
        //permittedArrowDirections 设置箭头方向
        [self.imagePicker presentPopoverFromRect:CGRectMake(0, 0, 300, 300) inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
    } 
}
/**
*实现代理
*/
//在这里处理获取到的图片
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
    // 获取图片
    UIImage *image = info[UIImagePickerControllerOriginalImage];
    [picker dismissViewControllerAnimated:YES completion:nil];
}
//点击取消按钮时调用
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [picker dismissViewControllerAnimated:YES completion:nil];
}

3.最后，在info.plist文件中配置相应的权限，如：”Privacy - Camera Usage Description “、"Privacy - Photo Library Usage Description"等