Objective c 合并两个图像并获得一个图像，但由于内存压力，应用程序崩溃

我的应用程序因内存压力而崩溃

在我的应用程序中，我组合了两个图像，得到一个图像，并使用此代码在UIImageView中设置此图像

+ (UIImage*)imageByCombiningImages:(UIImage*)firstImage withImage:(UIImage*)secondImage
{
    @autoreleasepool
    {
        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))];

        firstImage =nil;
        [secondImage drawAtPoint:CGPointMake(roundf((newImageSize.width-secondImage.size.width)/2), roundf((newImageSize.height-secondImage.size.height)/2))];


        secondImage=nil;

        image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return image;
    }
}

我一次调用该函数5次，并根据该函数返回的图像设置UIImageView

但在执行时，内存总是在增加，过了一段时间，应用程序就会崩溃

---

那么，告诉我如何降低内存压力？

您的问题可能来自其他方面。我只是在你的功能上运行仪器，一切正常

尖峰是当我点击运行代码的按钮时出现的。

代码如下：

+ (UIImage*)imageByCombiningImages:(UIImage*)firstImage withImage:(UIImage*)secondImage
{
    @autoreleasepool
    {
        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))];

        firstImage =nil;
        [secondImage drawAtPoint:CGPointMake(roundf((newImageSize.width-secondImage.size.width)/2), roundf((newImageSize.height-secondImage.size.height)/2))];


        secondImage=nil;

        image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return image;
    }
}

- (IBAction)callFunctionAction:(id)sender
{
    UIImage *firstImage = [UIImage imageNamed:@"image1"];
    UIImage *secondImage = [UIImage imageNamed:@"image2"];

    UIImage *thirdImage = [[self class] imageByCombiningImages:firstImage withImage:secondImage];
    self.imageView.image = thirdImage;
}

---

最后一行将抛出警告，但示例仍然有效

但是我调用了这个函数5到6次，并在UIImageView中设置了这个图像。我使用了2 MB大小和分辨率为1024*768的图像，以及视网膜iPad的视网膜图像。我刚刚在故事板上添加了一个UIImageView，并编辑了iAction以设置图像视图的图像，如下所示：self.imageView.image=thirdImage；仪器返回同样的东西。问题可能出在其他地方请看这个。。我是这样使用这个方法的……你用仪器测试过我的代码吗？您确定这是导致内存问题的代码部分吗？