ARC的EXC_BAD_ACCESS

时间:2012-06-28 10:30:06

标签: iphone objective-c ios automatic-ref-counting

我正在使用ARC,我有一个CustomTableViewController,我正在为我的背景单元格,页眉和页脚添加一个CustomView。

例如在tableView:viewForFooterInSection方法中,我放了以下这些代码:

- (UIView *) tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section
{
    CustomFooter *footer = [[CustomFooter alloc] init];
    return footer;
}

CustomFooter是UIView的子类,它使用- (void)drawRect:(CGRect)rect

绘制一个矩形作为背景单元格

当我在模拟器上运行应用程序时,但是当我尝试使用iPhone时它会崩溃。

我该如何解决?

这是我的崩溃报告:

Date/Time:       2012-06-28 12:37:07.168 +0200
OS Version:      iPhone OS 5.1.1 (9B206)
Report Version:  104

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x00000009
Crashed Thread:  0

Thread 0 name:  Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0   libobjc.A.dylib                 0x3508cf78 objc_msgSend + 16
1   CoreFoundation                  0x372d5e90 CFRetain + 76
2   CoreFoundation                  0x372dfb74 +[__NSArrayI __new::] + 48
3   CoreFoundation                  0x372dfa8e -[__NSPlaceholderArray   initWithObjects:count:] + 294
4   CoreFoundation                  0x3730ce68 +[NSArray arrayWithObjects:] + 460
5   CustomTable                     0x0004766e drawLinearGradient (Common.m:15)
6   CustomTable                     0x00048c14 -[CustomFooter drawRect:]   (CustomFooter.m:50)
7   UIKit                           0x3107015e -[UIView(CALayerDelegate) drawLayer:inContext:] + 270
8   QuartzCore                      0x374b74de -[CALayer drawInContext:] + 110
9   QuartzCore                      0x374b6b38 CABackingStoreUpdate_ + 1776
10  QuartzCore                      0x374b632e CA::Layer::display_() + 950
11  QuartzCore                      0x374b5f5a CA::Layer::display() + 122
12  QuartzCore                      0x374b5e9c CA::Layer::display_if_needed(CA::Transaction*) + 168
13  QuartzCore                      0x374b5844 CA::Context::commit_transaction(CA::Transaction*) + 228
14  QuartzCore                      0x374b5578 CA::Transaction::commit() + 308
15  QuartzCore                      0x374dd90a CA::Transaction::flush() + 38
16  QuartzCore                      0x374dd8dc +[CATransaction flush] + 28
17  UIKit                           0x310a6108 -[UIApplication _reportAppLaunchFinished] + 36
18  UIKit                           0x31093b2c -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 1256
19  UIKit                           0x31061abc -[UIApplication handleEvent:withNewEvent:] + 1004
20  UIKit                           0x31061560 -[UIApplication sendEvent:] + 48
21  UIKit                           0x31060f34 _UIApplicationHandleEvent + 5820
22  GraphicsServices                0x33aa3224 PurpleEventCallback + 876
23  CoreFoundation                  0x3736151c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 32
24  CoreFoundation                  0x373614be __CFRunLoopDoSource1 + 134
25  CoreFoundation                  0x3736030c __CFRunLoopRun + 1364
26  CoreFoundation                  0x372e349e CFRunLoopRunSpecific + 294
27  CoreFoundation                  0x372e3366 CFRunLoopRunInMode + 98
28  UIKit                           0x31092864 -[UIApplication _run] + 544
29  UIKit                           0x3108fcce UIApplicationMain + 1074
30  CustomTable                     0x00046798 main (main.m:16)
31  CustomTable                     0x0004673c start + 32

Thread 1 name:  Dispatch queue: com.apple.libdispatch-manager
Thread 1:
0   libsystem_kernel.dylib          0x315343a8 kevent + 24
1   libdispatch.dylib               0x304b9ea4 _dispatch_mgr_invoke + 708
2   libdispatch.dylib               0x304b9bc2 _dispatch_mgr_thread + 30

Thread 2:
0   libsystem_kernel.dylib          0x31544cd4 __workq_kernreturn + 8
1   libsystem_c.dylib               0x33bfcf36 _pthread_wqthread + 610
2   libsystem_c.dylib               0x33bfccc8 start_wqthread + 0

Thread 3:
0   libsystem_kernel.dylib          0x31544cd4 __workq_kernreturn + 8
1   libsystem_c.dylib               0x33bfcf36 _pthread_wqthread + 610
2   libsystem_c.dylib               0x33bfccc8 start_wqthread + 0

Thread 4 name:  WebThread
Thread 4:
0   libsystem_kernel.dylib          0x31534004 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x315341fa mach_msg + 50
2   CoreFoundation                  0x373613ec __CFRunLoopServiceMachPort + 120
3   CoreFoundation                  0x37360124 __CFRunLoopRun + 876
4   CoreFoundation                  0x372e349e CFRunLoopRunSpecific + 294
5   CoreFoundation                  0x372e3366 CFRunLoopRunInMode + 98
6   WebCore                         0x32c8cc9c _ZL12RunWebThreadPv + 396
7   libsystem_c.dylib               0x33c0272e _pthread_start + 314
8   libsystem_c.dylib               0x33c025e8 thread_start + 0

Thread 0 crashed with ARM Thread State:
r0: 0x00125860    r1: 0x30d16b7c      r2: 0x3f9a3570      r3: 0x0014b170
r4: 0x00000001    r5: 0x2fe41188      r6: 0x0014b178      r7: 0x2fe4114c
r8: 0x0014b170    r9: 0x0c345adf     r10: 0x00000002     r11: 0x00000001
ip: 0x3f97f814    sp: 0x2fe41140      lr: 0x372d5e97      pc: 0x3508cf78
cpsr: 0x00000030

这是我在CustomFooter中的drawRect函数:

- (void)drawRect:(CGRect)rect
{

CGContextRef context = UIGraphicsGetCurrentContext();

CGColorRef whiteColor = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:1.0].CGColor; 
CGColorRef lightGrayColor = [UIColor colorWithRed:230.0/255.0 green:230.0/255.0 blue:230.0/255.0 alpha:1.0].CGColor;
CGColorRef darkGrayColor = [UIColor colorWithRed:187.0/255.0 green:187.0/255.0 blue:187.0/255.0 alpha:1.0].CGColor;
CGColorRef shadowColor = [UIColor colorWithRed:0.2 green:0.2 blue:0.2 alpha:0.5].CGColor;

CGFloat paperMargin = 9.0;
CGRect paperRect = CGRectMake(self.bounds.origin.x+paperMargin, 
                              self.bounds.origin.y,
                              self.bounds.size.width-paperMargin*2, 
                              self.bounds.size.height);

CGRect arcRect = paperRect;
arcRect.size.height = 8;

CGContextSaveGState(context);
CGMutablePathRef arcPath = createArcPathFromBottomOfRect(arcRect, 4.0);
CGContextAddPath(context, arcPath);
CGContextClip(context);            
drawLinearGradient(context, paperRect, lightGrayColor, darkGrayColor);
CGContextRestoreGState(context);

CGContextSaveGState(context);
CGPoint pointA = CGPointMake(arcRect.origin.x, 
                             arcRect.origin.y + arcRect.size.height - 1);
CGPoint pointB = CGPointMake(arcRect.origin.x, arcRect.origin.y);
CGPoint pointC = CGPointMake(arcRect.origin.x + arcRect.size.width - 1, 
                             arcRect.origin.y);
CGPoint pointD = CGPointMake(arcRect.origin.x + arcRect.size.width - 1, 
                             arcRect.origin.y + arcRect.size.height - 1);
draw1PxStroke(context, pointA, pointB, whiteColor);
draw1PxStroke(context, pointC, pointD, whiteColor);    
CGContextRestoreGState(context);

CGContextAddRect(context, paperRect);
CGContextAddPath(context, arcPath);
CGContextEOClip(context);
CGContextAddPath(context, arcPath);
CGContextSetShadowWithColor(context, CGSizeMake(0, 2), 3.0, shadowColor);
CGContextFillPath(context);

CFRelease(arcPath);
}

drawLinearGradient

void drawLinearGradient(CGContextRef context, CGRect rect, CGColorRef startColor, CGColorRef  endColor)
{
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGFloat locations[] = { 0.0, 1.0 };
NSArray *colors = [NSArray arrayWithObjects:(__bridge id)startColor, (__bridge id)endColor, nil];
CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef) colors, locations);

CGPoint startPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMinY(rect));
CGPoint endPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMaxY(rect));

CGContextSaveGState(context);
CGContextAddRect(context, rect);
CGContextClip(context);
CGContextDrawLinearGradient(context, gradient, startPoint, endPoint, 0);
CGContextRestoreGState(context);

CGGradientRelease(gradient);
CGColorSpaceRelease(colorSpace);

}

2 个答案:

答案 0 :(得分:0)

此处没有足够的上下文可以确定地诊断问题,但我目前的猜测是,您的函数drawLinearRect()使用NSArray和参数中的一个对象创建arrayWithObjects:列表是垃圾。确保列表终止为零并且其中的所有对象都是合理的。

答案 1 :(得分:0)

JeremyP对数组初始化程序崩溃的分析是正确的。我猜测的根本原因是:

CGColorRef whiteColor = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:1.0].CGColor;

我的猜测是,由于你没有使用你在此声明之外创建的UIColor,因此ARC会热切地发布它。这也意味着你没有以任何方式保留的CGColor(以及ARC不会为你保留的那些)可能也被释放和解除分配。

尝试为每个UIColors使用类似的东西(对于白色的,只需使用[UIColor whiteColor]):

UIColor *color = [UIColor ...];
CGColorRef cgColor = CFRetain(color.CGColor);
color = nil;