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私はコアグラフィックスに少し慣れていませんが、エラーが発生し続け、それらをマージすると2番目の画像が表示されません:

- (UIImage*)imageByCombiningImage:(UIImage*)gfirstImage withImage:(UIImage*)gsecondImage atPositionX:(int)xPosition withPositionY:(int)yPosition{

    UIImage *firstImage = nil;
    UIImage *secondImage = nil;

    firstImage = gfirstImage;
    secondImage = gsecondImage;

    // int ratio = secondImage.size.height/secondImage.size.width;
    // int newWidth = firstImage.size.width/3;
    // int newHeight = (firstImage.size.height/3)*ratio;
    CGSize scaledSize = CGSizeMake(firstImage.size.width, firstImage.size.height);
    CGSize badgeScaledSize = scaledSize;
    if(firstImage.size.width > 500){
        scaledSize = CGSizeMake(firstImage.size.width/4, firstImage.size.height/3);
    }

    if(firstImage.size.width < firstImage.size.height){
        badgeScaledSize = CGSizeMake((firstImage.size.width/4)*prevPinchScale, (firstImage.size.height/4)*prevPinchScale);
    }

    if(firstImage.size.width > firstImage.size.height){
        badgeScaledSize = CGSizeMake((firstImage.size.width/4)*prevPinchScale, (firstImage.size.height/4)*prevPinchScale);
    }



    secondImage = [secondImage resizedImageWithContentMode:UIViewContentModeScaleAspectFit bounds:badgeScaledSize interpolationQuality:0.5];

    CGSize newImageSize = CGSizeMake(firstImage.size.width, firstImage.size.height);

    UIGraphicsBeginImageContext(newImageSize);

    NSLog(@"first image size width: %f, size height: %f", firstImage.size.width, firstImage.size.height);
    NSLog(@"first image size width: %f, size height: %f", newImageSize.width, newImageSize.height);

    [firstImage drawAtPoint:CGPointMake(0,
                                        0)];


    [secondImage drawAtPoint:CGPointMake(xPosition,
                                         yPosition)];

    UIImage *image = nil;
    image = UIGraphicsGetImageFromCurrentImageContext();

    NSLog(@"got image of width: %f and height: %f", image.size.width, image.size.height);

    UIGraphicsEndImageContext();


    return image;
}

エラーは次のとおりです。

 <Error>: CGContextConcatCTM: invalid context 0x0
 <Error>: CGContextSetInterpolationQuality: invalid context 0x0
 <Error>: CGContextDrawImage: invalid context 0x0
 <Error>: CGBitmapContextCreateImage: invalid context 0x0
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1 に答える 1

2

これらのエラーは、実際にはコードからスローされているのではなく、UIImage+Resize.m 内でスローされていると想定しています。行を削除すると、コードは正常に実行されます

secondImage = [secondImage resizedImageWithContentMode:UIViewContentModeScaleAspectFit bounds:badgeScaledSize interpolationQuality:0.5];

そのメソッドを見ると、エラーが発生している 4 つの呼び出しを行う別のメソッドを呼び出していることがわかります。

- (UIImage *)resizedImage:(CGSize)newSize
            transform:(CGAffineTransform)transform
       drawTransposed:(BOOL)transpose
 interpolationQuality:(CGInterpolationQuality)quality {
CGRect newRect = CGRectIntegral(CGRectMake(0, 0, newSize.width, newSize.height));
CGRect transposedRect = CGRectMake(0, 0, newRect.size.height, newRect.size.width);
CGImageRef imageRef = self.CGImage;

// Build a context that's the same dimensions as the new size
CGContextRef bitmap = CGBitmapContextCreate(NULL,
                                            newRect.size.width,
                                            newRect.size.height,
                                            CGImageGetBitsPerComponent(imageRef),
                                            0,
                                            CGImageGetColorSpace(imageRef),
                                            CGImageGetBitmapInfo(imageRef));

// Rotate and/or flip the image if required by its orientation
CGContextConcatCTM(bitmap, transform);

// Set the quality level to use when rescaling
CGContextSetInterpolationQuality(bitmap, quality);

// Draw into the context; this scales the image
CGContextDrawImage(bitmap, transpose ? transposedRect : newRect, imageRef);

// Get the resized image from the context and a UIImage
CGImageRef newImageRef = CGBitmapContextCreateImage(bitmap);
UIImage *newImage = [UIImage imageWithCGImage:newImageRef];

// Clean up
CGContextRelease(bitmap);
CGImageRelease(newImageRef);

return newImage;
}

値のビットマップが無効のようです。CGBitmapContextCreate 呼び出しで、実際の値を渡し、サイズ 0x0 のコンテキストを作成していないことを確認します。

于 2013-07-11T14:38:15.673 に答える