Ios 为Instagram安装612x612大小的完整图像，同时保持比例

我希望能够在612x612 UIImage中容纳任何完整图像，以便在我的应用程序中集成Instagram。但我不想切任何边或任何东西。我希望完整的图像天气在风景或肖像完全适合在一个612x612图像。我所追求的就像你可以设置一个图像内容模式，以适应图像视图中的纵横比。我正在寻找一种方法，可以将大小调整到我想要的大小（612x612），同时保持精确的比例

用户通过uiimageview选择现有图像，我希望选择的图像大小调整为612×612图像，同时保持相同的比率，但完全在612x612范围内。这里是一个示例，说明了当将长肖像图像调整为方形图像时，我希望长肖像图像的外观

我的instagram集成代码

NSURL *instagramURL = [NSURL URLWithString:@"instagram://app"];
                        if([[UIApplication sharedApplication] canOpenURL:instagramURL]) //check for App is install or not
                        {

                            UIImage *viewImage;

                            switch (whichPhoto) {
                                case 1:
                                    viewImage = photoOneImageView.image;
                                    break;
                                case 2:
                                    viewImage = photoTwoImageView.image;
                                    break;
                                case 3:
                                    viewImage = photoThreeImageView.image;
                                    break;

                                default:
                                    break;
                            }
                            //here is where i resize my image
                            viewImage = [self scaleImage:viewImage toSize:CGSizeMake(612, 612)];

                            NSData *imageData = UIImagePNGRepresentation(viewImage); //convert image into .png format.
                            NSFileManager *fileManager = [NSFileManager defaultManager];//create instance of NSFileManager
                            NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); //create an array and store result of our search for the documents directory in it
                            NSString *documentsDirectory = [paths objectAtIndex:0]; //create NSString object, that holds our exact path to the documents directory
                            NSString *fullPath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"insta.igo"]]; //add our image to the path
                            [fileManager createFileAtPath:fullPath contents:imageData attributes:nil]; //finally save the path (image)
                            NSLog(@"image saved");

                            CGRect rect = CGRectMake(0 ,0 , 0, 0);
                            UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, self.view.opaque, 0.0);
                            [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
                            UIGraphicsEndImageContext();
                            NSString *fileNameToSave = [NSString stringWithFormat:@"Documents/insta.igo"];
                            NSString  *jpgPath = [NSHomeDirectory() stringByAppendingPathComponent:fileNameToSave];
                            NSLog(@"jpg path %@",jpgPath);
                            NSString *newJpgPath = [NSString stringWithFormat:@"file://%@",jpgPath];
                            NSLog(@"with File path %@",newJpgPath);
                            NSURL *igImageHookFile = [[NSURL alloc]initFileURLWithPath:newJpgPath];
                            NSLog(@"url Path %@",igImageHookFile);

                            self.documentController.UTI = @"com.instagram.exclusivegram";
                            self.documentController = [self setupControllerWithURL:igImageHookFile usingDelegate:self];
                            self.documentController=[UIDocumentInteractionController interactionControllerWithURL:igImageHookFile];
                            NSString *caption = @"My caption"; //settext as Default Caption
                            self.documentController.annotation=[NSDictionary dictionaryWithObjectsAndKeys:[NSString stringWithFormat:@"%@",caption],@"InstagramCaption", nil];
                            [self.documentController presentOpenInMenuFromRect:rect inView: self.view animated:YES];
                        }
                        else
                        {
                            NSLog (@"Instagram not found");
                        }
                    }

但是我得到了这个

这里是我用于调整大小的作品的方法，几乎用于横向观看的图像，但不用于纵向

- (UIImage*) scaleImage:(UIImage*)image toSize:(CGSize)newSize {
    CGSize scaledSize = newSize;
    float scaleFactor = 1.0;
    if( image.size.width > image.size.height ) {
        scaleFactor = image.size.width / image.size.height;
        scaledSize.width = newSize.width;
        scaledSize.height = newSize.height / scaleFactor;
    }
    else {
        scaleFactor = image.size.height / image.size.width;
        scaledSize.height = newSize.height;
        scaledSize.width = newSize.width / scaleFactor;
    }

    UIGraphicsBeginImageContextWithOptions( scaledSize, NO, 0.0 );
    CGRect scaledImageRect = CGRectMake( 0.0, 0.0, scaledSize.width, scaledSize.height );
    [image drawInRect:scaledImageRect];
    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return scaledImage;
}

---

这将创建一个全屏图像，用于在Instagram上发布高度大于宽度的图像

UIImage *originalImage = [UIImage imageNamed:@"lion.jpg"];

// Create rect with height and width equal to originalImages height
CGSize size = CGSizeMake(originalImage.size.height, originalImage.size.height);
UIGraphicsBeginImageContextWithOptions(size, YES, 0);
// Fill the background with some color
[[UIColor lightGrayColor] setFill];
UIRectFill(CGRectMake(0, 0, size.width, size.height));
// Create image for what we just did
UIImage *bgImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

UIGraphicsBeginImageContext(bgImage.size);
// Take originalImage and center it in bgImage
// We get the center of bgImage by (bgImage.size.width / 2)
// But the coords of the originalImage start at the top left (0,0)
// So we need to subtract half of our orginalImages width so that it centers (bgImage.size.width / 2) - (originalImage.size.width / 2)
[originalImage drawInRect:CGRectMake((bgImage.size.width / 2) - (originalImage.size.width / 2), 0, originalImage.size.width, originalImage.size.height)];
// Create image for what we just did
UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

// Set your finalImage to a UIImageView or send it to Instagram
[self.final setImage:finalImage];

---

要对宽度大于高度的图像执行此操作，只需将

CGSize size

设置为

originalImages.size.width

。然后将其置于最终图像的中心，只需更改公式以计算高度而不是宽度。

我只需创建一个内容模式设置为aspect fit的图像视图，然后截图显示该图像视图。。如果其他人有更优雅的解决方案，请告诉我

                    UIImageView *imageview = [[UIImageView alloc] init];
                    imageview.contentMode = UIViewContentModeScaleAspectFit;
                    imageview.frame = CGRectMake(0, 0, 612, 612);
                    imageview.clipsToBounds = NO;
                    imageview.image = viewImage;

                   CGSize imageSize = CGSizeMake(imageview.bounds.size.width, imageview.bounds.size.height);
                    UIGraphicsBeginImageContext(imageSize);
                    [imageview.layer renderInContext:UIGraphicsGetCurrentContext()];
                    viewImage = UIGraphicsGetImageFromCurrentImageContext();
                    UIGraphicsEndImageContext();

---

你能提供一些代码来复习吗？我已经发布了一些代码，这些代码几乎适用于风景图片，但不适用于肖像图片@KalelWadeworks，适用于肖像图片，但它在风景图片的侧面略作删减images@4GetFullOf你没有完整地阅读我的答案吗？它的底部解释了如何处理风景图像。设置if语句以检查宽度是否大于高度，并适当更改代码以处理它。。。