將兩幅圖像合併爲單幅圖像，然後頂部圖像在ios sdk中變大

Question

我有兩個包含兩個不同圖像的imageView。我的firstImageview有主圖像，然後我添加了一個更多的imageview作爲firstImageview的子視圖，如[firstImageview addSubView:secondImageview]。我需要這個在一個單一的形象。

我使用下面的代碼（它工作順利）：

- (UIImage*)imageByCombiningImage:(UIImage*)firstImage withImage:(UIImage*)secondImage { 
    UIImage *image = nil; 

    CGSize newImageSize = CGSizeMake(MAX(firstImage.size.width, secondImage.size.width), MAX(firstImage.size.height, secondImage.size.height)); 
    if (UIGraphicsBeginImageContextWithOptions != NULL) { 
     UIGraphicsBeginImageContextWithOptions(newImageSize, NO, [[UIScreen mainScreen] scale]); 
    } else { 
     // UIGraphicsBeginImageContext(newImageSize); 
    } 
    [firstImage drawAtPoint:CGPointMake(roundf((newImageSize.width-firstImage.size.width)/2), 
             roundf((newImageSize.height-firstImage.size.height)/2))]; 
    [secondImage drawAtPoint:CGPointMake(roundf((newImageSize.width-secondImage.size.width)/2), 
             roundf((newImageSize.height-secondImage.size.height)/2))]; 
    image = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 

    return image; 
} 

但在我resultedImage，topImage secondImageview.image變大。

我的觀點看起來像（前合併）：

我造成的圖像合併後（上面的圖像變大）：

如何合併這些圖像，而不secondImageview變大？

Answer 1

我解決我的問題，通過下面的代碼

UIGraphicsBeginImageContextWithOptions(mainImageview.bounds.size, mainImageview.opaque, 0.0); 
[self.mainImageview.layer renderInContext:UIGraphicsGetCurrentContext()]; 
UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext();