UIImagePickerController - 从Apps文档目录中保存和检索照片 [英] UIImagePickerController - Save and Retrieve photo from Apps Document Directory

问题描述

这让我发疯了！

我已成功将照片保存到我的应用程序文档目录中，如果我从相机中选择现有照片滚。执行此操作的代码如下。注意我知道这部分工作正常，因为在模拟器中我可以浏览应用程序文档文件夹并查看正在保存的文件。

I'm successfully saving a photo to my applications document directory from both the camera and if I choose an existing one from the camera roll. The code to do this is as follows. Note I know this part is working because in the simulator I can browse to the apps Documents folder and see the file being saved.

示例保存代码：

//Note: code above snipped to keep this part of the question short
    case 1: 
    {
        // select from library
        NSLog(@"select from camera roll");

        if([util_ isPhotoLibraryAvailable])
        {
            UIImagePickerController *controller = [[UIImagePickerController alloc] init];
            controller.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
            NSMutableArray *mediaTypes = [[NSMutableArray alloc] init];
            if([util_ canUserPickPhotosFromPhotoLibrary])
            {
                [mediaTypes addObject:(__bridge NSString *)kUTTypeImage];
            }
            controller.mediaTypes = mediaTypes;
            controller.delegate = self;
            controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
            [self presentModalViewController:controller animated:YES];
        }
    } break;
//code below snipped out

一旦拍摄或选择了图像：

And once the image is taken or selected:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    NSLog(@"picker returned successfully");

    NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
    if([mediaType isEqualToString:(__bridge NSString *)kUTTypeImage])
    {
        UIImage *originalImage = [info objectForKey:UIImagePickerControllerOriginalImage]; 
        UIImage *resizedImage = [util_ createThumbnailForImage:originalImage thumbnailSize:[util_ determineIPhoneScreenSize]];
        NSData *imageData = UIImagePNGRepresentation(resizedImage);
        NSString* imageName = @"MyImage.png";
        NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString* documentsDirectory = [paths objectAtIndex:0];
        NSString* fullPathToFile = [documentsDirectory stringByAppendingPathComponent:imageName];        
        [imageData writeToFile:fullPathToFile atomically:NO];

        NSLog(@"fullPathToFile %@", fullPathToFile);
        // this outputs the following path in the debugger
        // fullPathToFile /Users/me/Library/Application Support/iPhone Simulator/5.0/Applications/47B01A4C-C54F-45C4-91A3-C4D7FF9F95CA/Documents/MyImage.png

        // rest snipped out - at this point I see the image in the simulators/app/Documents directory

现在 - 无法工作的部分（获取和显示照片）：

Now - the part that is NOT working (fetching and displaying the photo):

// code above snipped out (we're in tableView:cellForRowAtIndexPath)

imageButton_ = [[UIButton alloc] initWithFrame:CGRectMake(5, 5, 200, 200)];
NSString* imageName = [contentArray_ objectAtIndex:indexPath.row];
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
SString* documentsDirectory = [paths objectAtIndex:0];
NSString* fullPathToFile = [documentsDirectory stringByAppendingPathComponent:imageName];
UIImage *image = [UIImage imageNamed:fullPathToFile];
[imageButton_ setImage:image forState:UIControlStateNormal];

[cell addSubview:imageButton_];

NSLog(@"fullPathToFile: %@", fullPathToFile);
// this outputs the following path in the debugger
// fullPathToFile: /Users/me/Library/Application Support/iPhone Simulator/5.0/Applications/47B01A4C-C54F-45C4-91A3-C4D7FF9F95CA/Documents/MyImage.png

return cell;

}

所以，我得到了没有图像显示在单元格中的空按钮。我也用UIImageView替换了按钮但仍然没有运气...

So, I get an empty button with no image displayed in the cell. I have also substituted the button for a UIImageView and still no luck...

推荐答案

你的问题在这里：

UIImage *image = [UIImage imageNamed:fullPathToFile];

UIImage imageNamed：仅适用于中的图片捆绑。它不适用于文档目录中的图像。

UIImage imageNamed: is only for images in the bundle. It doesn't work for images in the documents directory.

请尝试 imageWithContentsOfFile：。

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