iOS判斷應用是否獲取到系統相機 相冊的授權 以及如何請求授權

</pre><pre code_snippet_id="1815940" snippet_file_name="blog_20160808_1_3554133" name="code" class="objc"><pre name="code" class="objc"> //判斷當前應用是否能訪問相冊資源
    /*
     typedef NS_ENUM(NSInteger, ALAuthorizationStatus) {
     ALAuthorizationStatusNotDetermined = 0, 用戶尚未做出了選擇這個應用程序的問候
     ALAuthorizationStatusRestricted,        此應用程序沒有被授權訪問的照片數據。可能是家長控制權限。

     ALAuthorizationStatusDenied,            用戶已經明確否認了這一照片數據的應用程序訪問.
     ALAuthorizationStatusAuthorized         用戶已授權應用訪問照片數據.
     }
     */

<pre name="code" class="objc">首先導入 AssetsLibrary.framework AVFoundation庫 導入頭文件

#import <AVFoundation/AVFoundation.h>
#import <AssetsLibrary/AssetsLibrary.h>

/**
 *  調用系統相機
 */
- (void)callCamera
{
    //判斷是否已授權
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0) {
        AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
        if (authStatus == ALAuthorizationStatusDenied||authStatus == ALAuthorizationStatusRestricted) {
            [self setAlertControllerWithTitle:@"提示" message:@"請前往設置->隱私->相機授權應用拍照權限" actionTitle:@"確定"];
            return ;
        }
    }
    // 判斷是否可以打開相機
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.allowsEditing = YES;
        picker.sourceType = UIImagePickerControllerSourceTypeCamera;
        [self presentViewController:picker animated:YES completion:nil];
    } else {
        [self setAlertControllerWithTitle:@"提示" message:@"你沒有相機" actionTitle:@"確定"];
    }
}
/**
 *  調用系統相冊
 */
- (void)callPhoto
{
    //判斷是否已授權
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0) {
        ALAuthorizationStatus authStatus = [ALAssetsLibrary authorizationStatus];
        if (authStatus == ALAuthorizationStatusDenied) {
            [self setAlertControllerWithTitle:@"提示" message:@"請前往設置->隱私->相冊授權應用訪問相冊權限" actionTitle:@"確定"];
            return;
        }

    }
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
        UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.allowsEditing = YES;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        //self.isReload = NO;
        [self presentViewController:picker animated:YES completion:nil];
    } else {
        [self setAlertControllerWithTitle:@"提示" message:@"你沒有相冊" actionTitle:@"確定"];
    }
}