将图像保存到/library/Application Support/bundleID_name/.iOS

Question

下面的代码工作没有错误或异常-但仍然，它没有做它应该做的！我想将图像保存到iOS库/应用程序支持文件夹中。更准确地说，应该将图像放置到/library/Application Support/bundleID_name/子文件夹/(以及称为“location1”的子文件夹中)。

如果我使用iOS-模拟器检查功能，我可以看到子文件夹的创建(即./library/Application Support/bundleID_name/location1/)。此外，"saveImage“函数也毫无例外地工作。但是没有图像被保存！(i.e.the图像文件丢失，文件夹保持为空)！

什么可能是错误?？

下面是调用两个函数的代码(请参阅下面的代码)：

UIImage *in_image = [UIImage imageNamed:@"template009c.jpg"];

NSString *locDirectoryName = @"location1";
NSURL *LocationDirectory = [self appendLocationToApplicationDirectory:locDirectoryName];

[self saveImage:in_image :@"image1" :LocationDirectory];

具有相应的函数-NR1：

- (NSURL*)appendLocationToApplicationDirectory:(NSString*)locationDirName
{
    NSString* appBundleID = [[NSBundle mainBundle] bundleIdentifier];
    NSFileManager*fm = [NSFileManager defaultManager];
    NSURL*    dirPath = nil;

    // Find the application support directory in the home directory.
    NSArray* appSupportDir = [fm URLsForDirectory:NSApplicationSupportDirectory
                                    inDomains:NSUserDomainMask];
    if ([appSupportDir count] > 0) {
        // Append the bundle ID and the location-Foldername to the URL for the Application Support directory
        dirPath = [[[appSupportDir objectAtIndex:0] URLByAppendingPathComponent:appBundleID] URLByAppendingPathComponent:locationDirName];

        // If the directory does not exist, this method creates it.
        // This method call works in OS X 10.7 and later only.
        NSError*    theError = nil;
        if (![fm createDirectoryAtURL:dirPath withIntermediateDirectories:YES attributes:nil error:&theError]) {
            // Handle the error.
            NSLog(@"%@", theError.localizedDescription);
            return nil;
        }
        else {
            // Mark the directory as excluded from iCloud backups
            if (![dirPath setResourceValue:@YES
                            forKey:NSURLIsExcludedFromBackupKey
                             error:&theError]) {
                NSLog(@"Error excluding %@ from iCloud backup %@", [dirPath lastPathComponent], theError.localizedDescription);
            }
            else {
                NSLog(@"Location Directory excluded from iClud backups");
            }
        }
    }
    return dirPath;
}

和函数Nr2：

//saving an image
- (void)saveImage:(UIImage*)image :(NSString*)imageName :(NSURL*)pathName {
    NSData *imageData = UIImagePNGRepresentation(image); //convert image into .png format.
    NSFileManager *fileManager = [NSFileManager defaultManager];
    // NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    // NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *LocationDirectory = [pathName absoluteString];
    NSString *fullPath = [LocationDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.png", imageName]];

    /***** THE FOLLOWING LINE DOES NOT SEEM TO DO WHAT IT IS SUPPOSED TO *******/
    [fileManager createFileAtPath:fullPath contents:imageData attributes:nil];

    /**** I also tried without the FileManager, but same problem - no file written...  ***/
    // [imageData writeToFile:fullPath atomically:NO];
    NSLog(@"image saved");
}

顺便说一下，使用XCode-Debugger获得"fullPath“，我得到：

"fullPath   NSPathStore2 *  @"file:/Users/username/Library/Application%20Support/iPhone%20Simulator/7.1/Applications/2BCC3345-9M55F-4580-A1E7-6694E33456777/Library/Application%20Support/bundleID_name/image1.png" 0x09d50950

这看起来也是对的吗？但是，为什么fileManager createFileAtPath:fullPath内容:imageData属性:无；未执行？

Answer 1

这是：

"fullPath   NSPathStore2 *  @"file:/Users/username/Library/Application%20Support/iPhone%20Simulator/7.1/Applications/2BCC3345-9M55F-4580-A1E7-6694E33456777/Library/Application%20Support/bundleID_name/image1.png" 0x09d50950

不是有效路径，而是存储在字符串中的URL路径。如果要使用URL，则使用ULRs，而不是尝试转换为字符串：

[imageData writeToURL:pathName atomically:YES];

(最好将参数命名为pathURL)，如果您想使用路径，那么在任何阶段都不要使用URL。

此外，如果API方法返回错误或状态标志，请在代码中作为标准检查它。

Answer 2

我很确定你不能在你指定的路径上保存一个图像。您可以在图库或DocumentDirectory中保存图像。这应该是在DocumentDirectory上保存图像的代码：

NSString *imgName=[@"imgname.png"];
[[NSUserDefaults standardUserDefaults]setValue:imgName forKey:@"imageName"];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,     NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];

NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:imgName];
UIImage *image = imageView.image; // imageView is my image from camera
NSData *imageData = UIImagePNGRepresentation(image);
[imageData writeToFile:savedImagePath atomically:NO];