ios使用預定義大小打印

Question

我製作了一個必須打印圖像的應用程序。我需要用預定義的大小打印圖像。

例如，我有一些圖像50 x 50像素我想調整它大小到一些新的大小的像素，打印後我得到的圖像大小5×5釐米。

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感謝您的幫助！

Answer 1

嘿，我已經使用下面的代碼，根據我的應用程序

設置大小調整圖像大小，你想

UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:[result objectForKey:@"pic"]]]]; 
     // Resize, crop the image to make sure it is square and renders 
     // well on Retina display 
     float ratio; 
     float delta; 
     float px = 100; // Double the pixels of the UIImageView (to render on Retina) 
     CGPoint offset; 
     CGSize size = image.size; 
     if (size.width > size.height) { 
      ratio = px/size.width; 
      delta = (ratio*size.width - ratio*size.height); 
      offset = CGPointMake(delta/2, 0); 
     } else { 
      ratio = px/size.height; 
      delta = (ratio*size.height - ratio*size.width); 
      offset = CGPointMake(0, delta/2); 
     } 
     CGRect clipRect = CGRectMake(-offset.x, -offset.y, 
            (ratio * size.width) + delta, 
            (ratio * size.height) + delta); 
     UIGraphicsBeginImageContext(CGSizeMake(px, px)); 
     UIRectClip(clipRect); 
     [image drawInRect:clipRect]; 
     UIImage *imgThumb = UIGraphicsGetImageFromCurrentImageContext(); 

     UIGraphicsEndImageContext(); 
     [img setImage:imgThumb];