使用泛洪填充在UIImage中填充颜色时出错

Question

感谢 Chintan R Dave 提供的 UIImageScanlineFloodfill。

我正在使用以下 UIImage 类别在闭合轮廓中填充颜色。它使用扫描线洪泛算法。

对于不是从设备捕获的图像，它可以正常工作。但是对于从设备捕获的图像，它会给出 EXC_BAD_ACCESS 错误（如问题末尾给出的截图所示）。众所周知，这种类型的错误很难解决。因此，我希望能得到一些关于如何解决此问题的建议。

代码如下：

UIImage+FloodFill.m

@implementation UIImage (FloodFill)
/*
    startPoint : Point from where you want to color. Generaly this is touch point.
                 This is important because color at start point will be replaced with other.

    newColor   : This color will be apply at point where the match on startPoint color found.

    tolerance  : If Tolerance is 0 than it will search for exact match of color 
                 other wise it will take range according to tolerance value.

                 If You dont want to use tolerance and want to incress performance Than you can change
                 compareColor(ocolor, color, tolerance) with just ocolor==color which reduse function call.
*/
- (UIImage *) floodFillFromPoint:(CGPoint)startPoint withColor:(UIColor *)newColor andTolerance:(int)tolerance
{
    return [self floodFillFromPoint:startPoint withColor:newColor andTolerance:tolerance useAntiAlias:YES];
}

- (UIImage *) floodFillFromPoint:(CGPoint)startPoint withColor:(UIColor *)newColor andTolerance:(int)tolerance useAntiAlias:(BOOL)antiAlias
{
    @try
    {
        /*
            First We create rowData from UIImage.
            We require this conversation so that we can use detail at pixel like color at pixel.
        */

        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

        CGImageRef imageRef = [self CGImage];

        NSUInteger width = CGImageGetWidth(imageRef);
        NSUInteger height = CGImageGetHeight(imageRef);

        unsigned char *imageData = malloc(height * width * 4);

        NSUInteger bytesPerPixel = CGImageGetBitsPerPixel(imageRef) / 8;
        NSUInteger bytesPerRow = CGImageGetBytesPerRow(imageRef);
        NSUInteger bitsPerComponent = CGImageGetBitsPerComponent(imageRef);

        CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);
        if (kCGImageAlphaLast == (uint32_t)bitmapInfo || kCGImageAlphaFirst == (uint32_t)bitmapInfo) {
            bitmapInfo = (uint32_t)kCGImageAlphaPremultipliedLast;
        }

        CGContextRef context = CGBitmapContextCreate(imageData,
                                                     width,
                                                     height,
                                                     bitsPerComponent,
                                                     bytesPerRow,
                                                     colorSpace,
                                                     bitmapInfo);
        CGColorSpaceRelease(colorSpace);

        CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);

        //Get color at start point 
        unsigned int byteIndex = (bytesPerRow * roundf(startPoint.y)) + roundf(startPoint.x) * bytesPerPixel;

        unsigned int ocolor = getColorCode(byteIndex, imageData);

        if (compareColor(ocolor, 0, 0)) {
            return nil;
        }

        //Convert newColor to RGBA value so we can save it to image.
        int newRed, newGreen, newBlue, newAlpha;

        const CGFloat *components = CGColorGetComponents(newColor.CGColor);


        if(CGColorGetNumberOfComponents(newColor.CGColor) == 2)
        {
            newRed   = newGreen = newBlue = components[0] * 255;
            newAlpha = components[1] * 255;
        }
        else if (CGColorGetNumberOfComponents(newColor.CGColor) == 4)
        {
            if ((bitmapInfo&kCGBitmapByteOrderMask) == kCGBitmapByteOrder32Little)
            {
                newRed   = components[2] * 255;
                newGreen = components[1] * 255;
                newBlue  = components[0] * 255;
                newAlpha = 255;
            }
            else
            {
                newRed   = components[0] * 255;
                newGreen = components[1] * 255;
                newBlue  = components[2] * 255;
                newAlpha = 255;
            }
        }

        unsigned int ncolor = (newRed << 24) | (newGreen << 16) | (newBlue << 8) | newAlpha;

        /*
            We are using stack to store point.
            Stack is implemented by LinkList.
            To incress speed I have used NSMutableData insted of NSMutableArray.
        */

        LinkedListStack *points = [[LinkedListStack alloc] initWithCapacity:500 incrementSize:500 andMultiplier:height];
        LinkedListStack *antiAliasingPoints = [[LinkedListStack alloc] initWithCapacity:500 incrementSize:500 andMultiplier:height];

        int x = roundf(startPoint.x);
        int y = roundf(startPoint.y);

        [points pushFrontX:x andY:y];

        /*
            Scanline Floodfill Algorithm With Stack (floodFillScanlineStack)
        */

        unsigned int color;
        BOOL spanLeft,spanRight;

        while ([points popFront:&x andY:&y] != INVALID_NODE_CONTENT)
        {
            byteIndex = (bytesPerRow * roundf(y)) + roundf(x) * bytesPerPixel;

            color = getColorCode(byteIndex, imageData);

            while(y >= 0 && compareColor(ocolor, color, tolerance))
            {
                y--;

                if(y >= 0)
                {
                    byteIndex = (bytesPerRow * roundf(y)) + roundf(x) * bytesPerPixel;

                    color = getColorCode(byteIndex, imageData);
                }
            }

            // Add the top most point on the antialiasing list
            if(y >= 0 && !compareColor(ocolor, color, 0))
            {
                [antiAliasingPoints pushFrontX:x andY:y];
            }

            y++;

            spanLeft = spanRight = NO;

            byteIndex = (bytesPerRow * roundf(y)) + roundf(x) * bytesPerPixel;

            color = getColorCode(byteIndex, imageData);

            while (y < height && compareColor(ocolor, color, tolerance) && ncolor != color)
            {
                //Change old color with newColor RGBA value

                imageData[byteIndex + 0] = newRed;
                imageData[byteIndex + 1] = newGreen;
                imageData[byteIndex + 2] = newBlue;
                imageData[byteIndex + 3] = newAlpha;

                if(x > 0)
                {
                    byteIndex = (bytesPerRow * roundf(y)) + roundf(x - 1) * bytesPerPixel;

                    color = getColorCode(byteIndex, imageData);

                    if(!spanLeft && x > 0 && compareColor(ocolor, color, tolerance))
                    {
                        [points pushFrontX:(x - 1) andY:y];

                        spanLeft = YES;
                    }
                    else if(spanLeft && x > 0 && !compareColor(ocolor, color, tolerance))
                    {
                        spanLeft = NO;
                    }

                    // we can't go left. Add the point on the antialiasing list
                    if(!spanLeft && x > 0 && !compareColor(ocolor, color, tolerance) && !compareColor(ncolor, color, tolerance))
                    {
                        [antiAliasingPoints pushFrontX:(x - 1) andY:y];
                    }
                }

                if(x < width - 1)
                {
                    byteIndex = (bytesPerRow * roundf(y)) + roundf(x + 1) * bytesPerPixel;;

                    color = getColorCode(byteIndex, imageData);

                    if(!spanRight && compareColor(ocolor, color, tolerance))
                    {
                        [points pushFrontX:(x + 1) andY:y];

                        spanRight = YES;
                    }
                    else if(spanRight && !compareColor(ocolor, color, tolerance))
                    {
                        spanRight = NO;
                    }

                    // we can't go right. Add the point on the antialiasing list
                    if(!spanRight && !compareColor(ocolor, color, tolerance) && !compareColor(ncolor, color, tolerance))
                    {
                        [antiAliasingPoints pushFrontX:(x + 1) andY:y];
                    }
                }

                y++;

                if(y < height)
                {
                    byteIndex = (bytesPerRow * roundf(y)) + roundf(x) * bytesPerPixel;

                    color = getColorCode(byteIndex, imageData);
                }
            }

            if (y<height)
            {
                byteIndex = (bytesPerRow * roundf(y)) + roundf(x) * bytesPerPixel;
                color = getColorCode(byteIndex, imageData);

                // Add the bottom point on the antialiasing list
                if (!compareColor(ocolor, color, 0))
                    [antiAliasingPoints pushFrontX:x andY:y];
            }
        }

        // For each point marked
        // perform antialiasing on the same pixel, plus the top,left,bottom and right pixel
        unsigned int antialiasColor = getColorCodeFromUIColor(newColor,bitmapInfo&kCGBitmapByteOrderMask );
        int red1   = ((0xff000000 & antialiasColor) >> 24);
        int green1 = ((0x00ff0000 & antialiasColor) >> 16);
        int blue1  = ((0x0000ff00 & antialiasColor) >> 8);
        int alpha1 =  (0x000000ff & antialiasColor);

        while ([antiAliasingPoints popFront:&x andY:&y] != INVALID_NODE_CONTENT)
        {
            byteIndex = (bytesPerRow * roundf(y)) + roundf(x) * bytesPerPixel;
            color = getColorCode(byteIndex, imageData);

            if (!compareColor(ncolor, color, 0))
            {
                int red2   = ((0xff000000 & color) >> 24);
                int green2 = ((0x00ff0000 & color) >> 16);
                int blue2 = ((0x0000ff00 & color) >> 8);
                int alpha2 =  (0x000000ff & color);

                if (antiAlias) {
                    imageData[byteIndex + 0] = (red1 + red2) / 2;
                    imageData[byteIndex + 1] = (green1 + green2) / 2;
                    imageData[byteIndex + 2] = (blue1 + blue2) / 2;
                    imageData[byteIndex + 3] = (alpha1 + alpha2) / 2;
                } else {
                    imageData[byteIndex + 0] = red2;
                    imageData[byteIndex + 1] = green2;
                    imageData[byteIndex + 2] = blue2;
                    imageData[byteIndex + 3] = alpha2;
                }

#if DEBUG_ANTIALIASING
                imageData[byteIndex + 0] = 0;
                imageData[byteIndex + 1] = 0;
                imageData[byteIndex + 2] = 255;
                imageData[byteIndex + 3] = 255;
#endif
            }

            // left
            if (x>0)
            {
                byteIndex = (bytesPerRow * roundf(y)) + roundf(x - 1) * bytesPerPixel;
                color = getColorCode(byteIndex, imageData);

                if (!compareColor(ncolor, color, 0))
                {
                    int red2   = ((0xff000000 & color) >> 24);
                    int green2 = ((0x00ff0000 & color) >> 16);
                    int blue2 = ((0x0000ff00 & color) >> 8);
                    int alpha2 =  (0x000000ff & color);

                    if (antiAlias) {
                        imageData[byteIndex + 0] = (red1 + red2) / 2;
                        imageData[byteIndex + 1] = (green1 + green2) / 2;
                        imageData[byteIndex + 2] = (blue1 + blue2) / 2;
                        imageData[byteIndex + 3] = (alpha1 + alpha2) / 2;
                    } else {
                        imageData[byteIndex + 0] = red2;
                        imageData[byteIndex + 1] = green2;
                        imageData[byteIndex + 2] = blue2;
                        imageData[byteIndex + 3] = alpha2;
                    }

#if DEBUG_ANTIALIASING
                    imageData[byteIndex + 0] = 0;
                    imageData[byteIndex + 1] = 0;
                    imageData[byteIndex + 2] = 255;
                    imageData[byteIndex + 3] = 255;
#endif
                }
            }
            if (x<width)
            {
                byteIndex = (bytesPerRow * roundf(y)) + roundf(x + 1) * bytesPerPixel;
                color = getColorCode(byteIndex, imageData);

                if (!compareColor(ncolor, color, 0))
                {
                    int red2   = ((0xff000000 & color) >> 24);
                    int green2 = ((0x00ff0000 & color) >> 16);
                    int blue2 = ((0x0000ff00 & color) >> 8);
                    int alpha2 =  (0x000000ff & color);

                    if (antiAlias) {
                        imageData[byteIndex + 0] = (red1 + red2) / 2;
                        imageData[byteIndex + 1] = (green1 + green2) / 2;
                        imageData[byteIndex + 2] = (blue1 + blue2) / 2;
                        imageData[byteIndex + 3] = (alpha1 + alpha2) / 2;
                    } else {
                        imageData[byteIndex + 0] = red2;
                        imageData[byteIndex + 1] = green2;
                        imageData[byteIndex + 2] = blue2;
                        imageData[byteIndex + 3] = alpha2;
                    }

#if DEBUG_ANTIALIASING
                    imageData[byteIndex + 0] = 0;
                    imageData[byteIndex + 1] = 0;
                    imageData[byteIndex + 2] = 255;
                    imageData[byteIndex + 3] = 255;
#endif
                }

            }

            if (y>0)
            {
                byteIndex = (bytesPerRow * roundf(y - 1)) + roundf(x) * bytesPerPixel;
                color = getColorCode(byteIndex, imageData);

                if (!compareColor(ncolor, color, 0))
                {
                    int red2   = ((0xff000000 & color) >> 24);
                    int green2 = ((0x00ff0000 & color) >> 16);
                    int blue2 = ((0x0000ff00 & color) >> 8);
                    int alpha2 =  (0x000000ff & color);

                    if (antiAlias) {
                        imageData[byteIndex + 0] = (red1 + red2) / 2;
                        imageData[byteIndex + 1] = (green1 + green2) / 2;
                        imageData[byteIndex + 2] = (blue1 + blue2) / 2;
                        imageData[byteIndex + 3] = (alpha1 + alpha2) / 2;
                    } else {
                        imageData[byteIndex + 0] = red2;
                        imageData[byteIndex + 1] = green2;
                        imageData[byteIndex + 2] = blue2;
                        imageData[byteIndex + 3] = alpha2;
                    }

#if DEBUG_ANTIALIASING
                    imageData[byteIndex + 0] = 0;
                    imageData[byteIndex + 1] = 0;
                    imageData[byteIndex + 2] = 255;
                    imageData[byteIndex + 3] = 255;
#endif
                }
            }

            if (y<height)
            {
                byteIndex = (bytesPerRow * roundf(y + 1)) + roundf(x) * bytesPerPixel;
                color = getColorCode(byteIndex, imageData);

                if (!compareColor(ncolor, color, 0))
                {
                    int red2   = ((0xff000000 & color) >> 24);
                    int green2 = ((0x00ff0000 & color) >> 16);
                    int blue2 = ((0x0000ff00 & color) >> 8);
                    int alpha2 =  (0x000000ff & color);

                    if (antiAlias) {
                        imageData[byteIndex + 0] = (red1 + red2) / 2;
                        imageData[byteIndex + 1] = (green1 + green2) / 2;
                        imageData[byteIndex + 2] = (blue1 + blue2) / 2;
                        imageData[byteIndex + 3] = (alpha1 + alpha2) / 2;
                    } else {
                        imageData[byteIndex + 0] = red2;
                        imageData[byteIndex + 1] = green2;
                        imageData[byteIndex + 2] = blue2;
                        imageData[byteIndex + 3] = alpha2;
                    }

#if DEBUG_ANTIALIASING
                    imageData[byteIndex + 0] = 0;
                    imageData[byteIndex + 1] = 0;
                    imageData[byteIndex + 2] = 255;
                    imageData[byteIndex + 3] = 255;
#endif
                }

            }
        }

        //Convert Flood filled image row data back to UIImage object.

        CGImageRef newCGImage = CGBitmapContextCreateImage(context);

        UIImage *result = [UIImage imageWithCGImage:newCGImage scale:[self scale] orientation:UIImageOrientationUp];

        CGImageRelease(newCGImage);

        CGContextRelease(context);

        free(imageData);

        return result;
    }
    @catch (NSException *exception)
    {
        NSLog(@"Exception : %@", exception);
    }
}

/*
    I have used pure C function because it is said than C function is faster than Objective - C method in call.
    This two function are called most of time so it require that calling this work in speed.
    I have not verified this performance so I like to here comment on this.
*/
/*
    This function extract color from image and convert it to integer represent.
    Converting to integer make comperation easy.
*/
unsigned int getColorCode (unsigned int byteIndex, unsigned char *imageData)
{
    unsigned int red   = imageData[byteIndex];
    unsigned int green = imageData[byteIndex + 1];
    unsigned int blue  = imageData[byteIndex + 2];
    unsigned int alpha = imageData[byteIndex + 3];

    return (red << 24) | (green << 16) | (blue << 8) | alpha;
}

/*
    This function compare two color with counting tolerance value.

    If color is between tolerance rancge than it return true other wise false.
*/
bool compareColor (unsigned int color1, unsigned int color2, int tolorance)
{
    if(color1 == color2)
        return true;

    int red1   = ((0xff000000 & color1) >> 24);
    int green1 = ((0x00ff0000 & color1) >> 16);
    int blue1  = ((0x0000ff00 & color1) >> 8);
    int alpha1 =  (0x000000ff & color1);

    int red2   = ((0xff000000 & color2) >> 24);
    int green2 = ((0x00ff0000 & color2) >> 16);
    int blue2  = ((0x0000ff00 & color2) >> 8);
    int alpha2 =  (0x000000ff & color2);

    int diffRed   = abs(red2   - red1);
    int diffGreen = abs(green2 - green1);
    int diffBlue  = abs(blue2  - blue1);
    int diffAlpha = abs(alpha2 - alpha1);

    if( diffRed   > tolorance ||
        diffGreen > tolorance ||
        diffBlue  > tolorance ||
        diffAlpha > tolorance  )
    {
        return false;
    }

    return true;
}

unsigned int getColorCodeFromUIColor(UIColor *color, CGBitmapInfo orderMask)
{
    //Convert newColor to RGBA value so we can save it to image.
    int newRed, newGreen, newBlue, newAlpha;

    const CGFloat *components = CGColorGetComponents(color.CGColor);

    if(CGColorGetNumberOfComponents(color.CGColor) == 2)
    {
        newRed   = newGreen = newBlue = components[0] * 255;
        newAlpha = components[1] * 255;
    }
    else if (CGColorGetNumberOfComponents(color.CGColor) == 4)
    {
        if (orderMask == kCGBitmapByteOrder32Little)
        {
            newRed   = components[2] * 255;
            newGreen = components[1] * 255;
            newBlue  = components[0] * 255;
            newAlpha = 255;
        }
        else
        {
            newRed   = components[0] * 255;
            newGreen = components[1] * 255;
            newBlue  = components[2] * 255;
            newAlpha = 255;
        }
    }
    else
    {
        newRed   = newGreen = newBlue = 0;
        newAlpha = 255;
    }

    unsigned int ncolor = (newRed << 24) | (newGreen << 16) | (newBlue << 8) | newAlpha;

    return ncolor;
}

@end

LinkedListStack.h

#import <Foundation/Foundation.h>

#define FINAL_NODE_OFFSET -1
#define INVALID_NODE_CONTENT INT_MIN
typedef struct PointNode
{
    int nextNodeOffset;

    int point;

} PointNode;

@interface LinkedListStack : NSObject
{
    NSMutableData *nodeCache;

    int freeNodeOffset;
    int topNodeOffset;
    int _cacheSizeIncrements;

    int multiplier;
}

- (id)initWithCapacity:(int)capacity incrementSize:(int)increment andMultiplier:(int)mul;
- (id)initWithCapacity:(int)capacity;

- (void)pushFrontX:(int)x andY:(int)y;
- (int)popFront:(int *)x andY:(int *)y;
@end

LinkedListStack.m

#import "LinkedListStack.h"

@implementation LinkedListStack

#pragma mark - Initialisation
/*
    A linked List is create with size of <capicity>.
    When you add more element that <capicity> than Lisk List is incressed by size <increment>
    mul is value for H (for H see comment Stack methods)
*/
- (id)init
{
    return [self initWithCapacity:500];
}

- (id)initWithCapacity:(int)capacity
{
    return [self initWithCapacity:capacity incrementSize:500 andMultiplier:1000];
}

- (id)initWithCapacity:(int)capacity incrementSize:(int)increment andMultiplier:(int)mul
{
    self = [super init];

    if(self)
    {
        _cacheSizeIncrements = increment;

        int bytesRequired = capacity * sizeof(PointNode);

        nodeCache = [[NSMutableData alloc] initWithLength:bytesRequired];

        [self initialiseNodesAtOffset:0 count:capacity];

        freeNodeOffset = 0;
        topNodeOffset = FINAL_NODE_OFFSET;

        multiplier = mul;
    }

    return self;
}

#pragma mark - Stack methods
/*
    X and Y are converted in single integer value (P) to push in stack.
    And again that value (P) are converted to X and Y when pop by using following equation:

    P = H * X + Y

    X = P / H;
    Y = P % H;

    H is same for all X and Y and must be grater than Y. So generaly Height is prefered value;
*/
- (void)pushFrontX:(int)x andY:(int)y;
{
    int p = multiplier * x + y;

    PointNode *node = [self getNextFreeNode];

    node->point = p;
    node->nextNodeOffset = topNodeOffset;

    topNodeOffset = [self offsetOfNode:node];
}

- (int)popFront:(int *)x andY:(int *)y;
{
    if(topNodeOffset == FINAL_NODE_OFFSET)
    {
        return INVALID_NODE_CONTENT;
    }

    PointNode *node = [self nodeAtOffset:topNodeOffset];

    int thisNodeOffset = topNodeOffset;

    // Remove this node from the queue
    topNodeOffset = node->nextNodeOffset;
    int value = node->point;

    // Reset it and add it to the free node cache
    node->point = 0;
    node->nextNodeOffset = freeNodeOffset;

    freeNodeOffset = thisNodeOffset;

    *x = value / multiplier;
    *y = value % multiplier;

    return value;
}

#pragma mark - utility functions
- (int)offsetOfNode:(PointNode *)node
{
    return node - (PointNode *)nodeCache.mutableBytes;
}

- (PointNode *)nodeAtOffset:(int)offset
{
    return (PointNode *)nodeCache.mutableBytes + offset;
}

- (PointNode *)getNextFreeNode
{
    if(freeNodeOffset < 0)
    {
        // Need to extend the size of the nodeCache
        int currentSize = nodeCache.length / sizeof(PointNode);
        [nodeCache increaseLengthBy:_cacheSizeIncrements * sizeof(PointNode)];

        // Set these new nodes to be the free ones
        [self initialiseNodesAtOffset:currentSize count:_cacheSizeIncrements];
        freeNodeOffset = currentSize;
    }

    PointNode *node = (PointNode*)nodeCache.mutableBytes + freeNodeOffset;
    freeNodeOffset = node->nextNodeOffset;

    return node;
}

- (void)initialiseNodesAtOffset:(int)offset count:(int)count
{
    PointNode *node = (PointNode *)nodeCache.mutableBytes + offset;

    for (int i=0; i<count - 1; i++)
    {
        node->point = 0;
        node->nextNodeOffset = offset + i + 1;
        node++;
    }

    node->point = 0;

    // Set the next node offset to make sure we don't continue
    node->nextNodeOffset = FINAL_NODE_OFFSET;
}

出错的代码：

unsigned int getColorCode (unsigned int byteIndex, unsigned char *imageData)
{
    unsigned int red   = imageData[byteIndex];
    unsigned int green = imageData[byteIndex + 1];
    unsigned int blue  = imageData[byteIndex + 2];
    unsigned int alpha = imageData[byteIndex + 3];

    return (red << 24) | (green << 16) | (blue << 8) | alpha;
}

截图

导致错误的图像：

- Pawan Joshi

---

请分享导致崩溃的图片。 - gabbler

出现了相同的错误，有任何更新吗？ - Julio

@JulioVasquez：我最终采用了不同的方法。请给我你的电子邮件，我会把代码发送给你。 - Pawan Joshi

Answer 1

我在github仓库的一个开放问题上解决了这个问题，链接在此here。

问题出现在UIImage+Floodfill.m文件中的大约60行左右。

CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);

大约在第40行，该类调用：

CGImageRef imageRef = [self CGImage];

因此，我使用了图像的NSData而不是通过那种方式获取CGImageRef：

CGDataProviderRef imgDataProvider = CGDataProviderCreateWithCFData((CFDataRef)UIImagePNGRepresentation(self));

CGImageRef imageRef = CGImageCreateWithPNGDataProvider(imgDataProvider, NULL, true, kCGRenderingIntentDefault);

我将它制作为PNG格式，因为我使用库来进行alpha泛洪填充，而不是纯色填充。只要CGDataRef和CGImageRef从相同的格式获取，就可以修复错误访问崩溃。此外，我没有包含持有这些对象的内存释放，因为我稍后在代码中执行，但只是想指出这一点。

回答有点晚了，但希望这对使用该代码的任何人有所帮助。

- LilDwarf

Answer 2

当您调用一个已释放的对象时，它会变成"僵尸"。

您可以按照以下步骤找出问题所在：

1. 在“编辑方案”中启用僵尸对象

2. 在Xcode中使用Profile而不是普通运行（长按运行按钮）

3. 然后使用其中一个工具（例如[zombie]）

并记录活动

您可以关注this link，因为我没有足够的声望来发布超过两个链接！

- Gurjot Kalsi