[iOS]UIImageをリサイズする

+ (UIImage *)resize:(UIImage *)image rect:(CGRect)rect
{
    UIGraphicsBeginImageContext(rect.size);
    [image drawInRect:rect];
    UIImage* resizedImage = UIGraphicsGetImageFromCurrentImageContext();
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetInterpolationQuality(context, kCGInterpolationHigh);
    UIGraphicsEndImageContext();
    return resizedImage;
}

[iOS]ディスプレイと画像の比率を求める

- (float)getScale :(CGSize)displaySize :(CGSize)imageSize {
    float scale = 0.0;
    
    if (imageSize.height > displaySize.height) {
        scale = displaySize.height / imageSize.height;
    } else {
        scale = imageSize.height / displaySize.height;
    }
    
    return scale;
}

[iOS]メールを送信

- (void)sendMail
    if([MFMailComposeViewController canSendMail] == YES) { //メーラーが使用できるかどうか
        MFMailComposeViewController *controller = [[MFMailComposeViewController alloc] init];
        [controller setSubject:@"subject"]; //題名
        [controller setMessageBody:@"message" isHTML:NO]; //本文
        controller.mailComposeDelegate = self; //成功、失敗時にdelegateを送る
        [self presentViewController:controller animated:YES completion:nil]; //ViewContrllerとして立ち上げる
    }
}

- (void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error
{
    [self dismissViewControllerAnimated:YES completion:nil]; //終了時にViewContrllerを閉じる
    return;
}