調用系統相機和系統相冊，并儲存到沙盒中

調用系統相冊或系統相機，用到的是

**UIImagePickerController**

。要遵循兩個協定UIImagePickerControllerDelegate,UINavigationControllerDelegate。

具體代碼如下：

調用相冊：

self.imagePicker = [[UIImagePickerController alloc]init];
    self.imagePicker.allowsEditing = YES;
    self.imagePicker.delegate = self;
    self.imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    self.imagePicker.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
    [self presentViewController:self.imagePicker animated:YES completion:nil];
           

在上面的sourceType分為三種：

typedef NS_ENUM(NSInteger, UIImagePickerControllerSourceType) {
    UIImagePickerControllerSourceTypePhotoLibrary,//相冊
    UIImagePickerControllerSourceTypeCamera,//相機
    UIImagePickerControllerSourceTypeSavedPhotosAlbum//圖檔庫
} __TVOS_PROHIBITED;
           

當調用系統相機時，使用UIImagePickerControllerSourceTypeCamera這個類型

//處理點選拍照
        UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypeCamera;
        if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
            [self showHUDMessage:@"相機不可用"];//這裡判斷相機可不可以用
        }else{
            self.imagePicker = [[UIImagePickerController alloc]init];
            self.imagePicker.allowsEditing = YES;
            self.imagePicker.delegate = self;
            self.imagePicker.sourceType = sourceType;
            self.imagePicker.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];
            [self presentViewController:self.imagePicker animated:YES completion:nil];
        }
           

實作代理方法：

pragma mark - ****************  選擇圖檔回調方法
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{
    UIImage *image = info[UIImagePickerControllerEditedImage];//擷取選擇的圖檔
    _lostImageView.image = image;
    [self dismissViewControllerAnimated:YES completion:nil];
}
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
    [self dismissViewControllerAnimated:YES completion:nil];
}
           

寫入沙盒:

pragma mark 擷取沙盒中完整的檔案路徑
-(NSString *)getFilePath:(NSString *)fileName{
    NSString *filePath;

    //擷取沙盒Documents目錄路徑
    NSArray *docPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,  NSUserDomainMask, YES);
    NSString *docPath = docPaths[];
    //跟檔案名組合起來(使用NSString的執行個體方法stringByAppendingPathComponent: 組成檔案的完整路徑）
    filePath = [docPath stringByAppendingPathComponent:fileName];
    NSLog(@"filePath：%@",filePath);
    return filePath;
}
/**
 * 将圖檔寫進沙盒
 */
-(void)writeImageToDocPathsWith:(NSString *)imageName{
    //1、擷取檔案管理器（NSFileManager的類方法defaultManager：）
    NSFileManager *fileManager = [NSFileManager defaultManager];

    //2、檢查檔案是否存在（NSFileManager的執行個體方法fileExistsAtPath: ，參數是檔案路徑，需要調用方法擷取）
    _filePath = [self getFilePath:[NSString stringWithFormat:@"%@.png",imageName]];
    if (![fileManager fileExistsAtPath:_filePath]) {
        //2.1、不存在此檔案的話，建立該檔案（NSFileManager的createFileAtPath: contents: attributes:執行個體方法)
        [fileManager createFileAtPath:_filePath contents:nil attributes:nil];
    }

    //3、寫入檔案内容，建立一個NSFileHandle，相當于打開（NSFileHandle的fileHandleForWritingAtPath:類方法）
    NSFileHandle *fileHandle = [NSFileHandle fileHandleForWritingAtPath:_filePath];

    //4、寫入内容（擷取内容字元串，調用内容字元串的dataUsingEncoding:執行個體方法轉換成NSData類型，調用NSFileHandle的執行個體方法writeData:寫入檔案）

    NSData *fileData = UIImagePNGRepresentation(_lostImageView.image);    //[fileHandle truncateFileAtOffset:0];//相當于覆寫檔案
    //檔案句柄指向檔案末尾，相當于給檔案追加内容
    [fileHandle seekToEndOfFile];
    //寫檔案
    [fileHandle writeData:fileData];


    //5、寫入完成之後關閉檔案（調用NSFileHandle的執行個體方法closeFile:）
    [fileHandle closeFile];

}