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因为最近APP总会有很多Crash信息定位在主函数main里面,所以发现很多出现的BUG不好定位修改,所以就想通过iOS的runtime机制,自己写个防crash机制,并且收集信息.
当然通过google,和百度的一系列查询后,大概Copy了个简单的Crash信息防护,和收集系统,借鉴的资料有网易一个团队的大白系统 http://www.jianshu.com/p/02157577d4e7 (我记得他们说要开源,等了好久,还没有消息),
还有chenfanfang的很多文章 和春田花花幼儿园的简书
通过runtime如何防止Crash
相信做个iOS开发的朋友都知道,OC是个动态语言,其中很主要的就是消息机制,在运行的过程中通过消息机制动态的调用对应函数.所以我们就可以想办法在处理对应函数的时候,替换掉系统的方法来执行.
如果出现错误,我们可以把错误信息获取到,同时让Crash的方法不在继续执行,无效化.
示例代码
比如我们创建个可变数组,之后再插入数据,因为数组越界会造成程序crash,并且控制台提示信息.
NSMutableArray *muArray = [NSMutableArray new];
[muArray setObject:@"crash" atIndexedSubscript:1];
控制台信息
reason: '*** -[__NSArrayM setObject:atIndexedSubscript:]: index 1 beyond bounds for empty array'
接下来就是我们创造个类,来替换掉系统NSMutableArray的setObject 方法
#import <Foundation/Foundation.h>
@interface NSMutableArray (Crash)
@end
@implementation 就是对应的作用域,@implementation NSMutableArray意思就是对应所有可变数组.
#import "NSMuableArray+Crash.h"
#import <objc/runtime.h>
#define AvoidCrashSeparator @"================================================================"
#define AvoidCrashSeparatorWithFlag @"========================AvoidCrash Log=========================="
#define AvoidCrashDefaultIgnore @"This framework default is to ignore this operation to avoid crash."
#define key_errorName @"errorName"
#define key_errorReason @"errorReason"
#define key_errorPlace @"errorPlace"
#define key_defaultToDo @"defaultToDo"
#define key_callStackSymbols @"callStackSymbols"
#define key_exception @"exception"
@implementation NSMutableArray (Crash)
+(void)load
{
// 执行一次.
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Class muArrayClass = NSClassFromString(@"__NSArrayM");
SEL originalMethodSel = @selector(setObject:atIndexedSubscript:);
SEL swizzledMethodSel = @selector(KsetObject:atIndexedSubscript:);
Method originalMethod = class_getInstanceMethod(muArrayClass, originalMethodSel);
Method swizzledMethod = class_getInstanceMethod(muArrayClass, swizzledMethodSel);
BOOL didAddMethod =
class_addMethod(muArrayClass,
originalMethodSel,
method_getImplementation(swizzledMethod),
method_getTypeEncoding(swizzledMethod));
if (didAddMethod) {
class_replaceMethod(muArrayClass,
originalMethodSel,
method_getImplementation(originalMethod),
method_getTypeEncoding(originalMethod));
}
else {
method_exchangeImplementations(originalMethod, swizzledMethod);
}
});
}
- (void)KsetObject:(id)object atIndexedSubscript:(NSInteger)index{
// 可能crash的方法,并且获取crash的信息
@try {
// 因为交换过方法,所以在此调用这个其实是调用的系统原先的方法.
[self KsetObject:object atIndexedSubscript:index];
} @catch (NSException *exception) {
[self noteErrorWithException:exception defaultToDo:AvoidCrashDefaultIgnore];
} @finally {
// 这里面的代码一定会执行.
}
}
/**
* 获取堆栈主要崩溃精简化的信息<根据正则表达式匹配出来>
*
* @param callStackSymbols 堆栈主要崩溃信息
*
* @return 堆栈主要崩溃精简化的信息
*/
- (NSString *)getMainCallStackSymbolMessageWithCallStackSymbols:(NSArray<NSString *> *)callStackSymbols {
//mainCallStackSymbolMsg的格式为 +[类名 方法名] 或者 -[类名 方法名]
__block NSString *mainCallStackSymbolMsg = nil;
//匹配出来的格式为 +[类名 方法名] 或者 -[类名 方法名]
NSString *regularExpStr = @"[-\\+]\\[.+\\]";
NSRegularExpression *regularExp = [[NSRegularExpression alloc] initWithPattern:regularExpStr options:NSRegularExpressionCaseInsensitive error:nil];
for (int index = 2; index < callStackSymbols.count; index++) {
NSString *callStackSymbol = callStackSymbols[index];
[regularExp enumerateMatchesInString:callStackSymbol options:NSMatchingReportProgress range:NSMakeRange(0, callStackSymbol.length) usingBlock:^(NSTextCheckingResult * _Nullable result, NSMatchingFlags flags, BOOL * _Nonnull stop) {
if (result) {
NSString* tempCallStackSymbolMsg = [callStackSymbol substringWithRange:result.range];
//get className
NSString *className = [tempCallStackSymbolMsg componentsSeparatedByString:@" "].firstObject;
className = [className componentsSeparatedByString:@"["].lastObject;
NSBundle *bundle = [NSBundle bundleForClass:NSClassFromString(className)];
//filter category and system class
if (![className hasSuffix:@")"] && bundle == [NSBundle mainBundle]) {
mainCallStackSymbolMsg = tempCallStackSymbolMsg;
}
*stop = YES;
}
}];
if (mainCallStackSymbolMsg.length) {
break;
}
}
return mainCallStackSymbolMsg;
}
/**
* 提示崩溃的信息(控制台输出、通知)
*
* @param exception 捕获到的异常
* @param defaultToDo 这个框架里默认的做法
*/
- (void)noteErrorWithException:(NSException *)exception defaultToDo:(NSString *)defaultToDo {
//堆栈数据
NSArray *callStackSymbolsArr = [NSThread callStackSymbols];
//获取在哪个类的哪个方法中实例化的数组 字符串格式 -[类名 方法名] 或者 +[类名 方法名]
NSString *mainCallStackSymbolMsg = [self getMainCallStackSymbolMessageWithCallStackSymbols:callStackSymbolsArr];
if (mainCallStackSymbolMsg == nil) {
mainCallStackSymbolMsg = @"崩溃方法定位失败,请您查看函数调用栈来排查错误原因";
}
NSString *errorName = exception.name;
NSString *errorReason = exception.reason;
//errorReason 可能为 -[__NSCFConstantString avoidCrashCharacterAtIndex:]: Range or index out of bounds
//将avoidCrash去掉
errorReason = [errorReason stringByReplacingOccurrencesOfString:@"avoidCrash" withString:@""];
NSString *errorPlace = [NSString stringWithFormat:@"Error Place:%@",mainCallStackSymbolMsg];
NSDictionary *errorInfoDic = @{
key_errorName : errorName,
key_errorReason : errorReason,
key_errorPlace : errorPlace,
key_defaultToDo : defaultToDo,
key_exception : exception,
key_callStackSymbols : callStackSymbolsArr
};
//将错误信息放在字典里，用通知的形式发送出去
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(@"%@",errorInfoDic);
});
}
@end
数组越界APP并没有Crash,打印exception信息
2017-07-27 10:21:00.099509+0800 CrashDemo[6760:791263] {
callStackSymbols = (
0 CrashDemo 0x000000010091bf10 -[NSMutableArray(NSMutableArray_Crash) noteErrorWithException:defaultToDo:] + 144
1 CrashDemo 0x000000010091b634 -[NSMutableArray(NSMutableArray_Crash) KsetObject:atIndexedSubscript:] + 296
2 CrashDemo 0x000000010091b014 -[ViewController viewDidLoad] + 144
3 UIKit 0x000000018d2fd184 <redacted> + 1040
4 UIKit 0x000000018d2fcd5c <redacted> + 28
5 UIKit 0x000000018d303a8c <redacted> + 136
6 UIKit 0x000000018d300cf8 <redacted> + 272
7 UIKit 0x000000018d370664 <redacted> + 48
8 UIKit 0x000000018d55f3a4 <redacted> + 3616
9 UIKit 0x000000018d56414c <redacted> + 1712
10 UIKit 0x000000018d7e5780 <redacted> + 136
11 UIKit 0x000000018daaaec4 <redacted> + 160
12 UIKit 0x000000018d7e567c <redacted> + 252
13 UIKit 0x000000018d7e5b20 <redacted> + 756
14 UIKit 0x000000018df26978 <redacted> + 244
15 UIKit 0x000000018df2682c <redacted> + 448
16 UIKit 0x000000018dcb56b8 <redacted> + 220
17 UIKit 0x000000018de4262c _performActionsWithDelayForTransitionContext + 112
18 UIKit 0x000000018dcb5568 <redacted> + 252
19 UIKit 0x000000018daaa544 <redacted> + 364
20 UIKit 0x000000018d562890 <redacted> + 540
21 UIKit 0x000000018d953214 <redacted> + 364
22 FrontBoardServices 0x0000000185ea2968 <redacted> + 364
23 FrontBoardServices 0x0000000185eab270 <redacted> + 224
24 libdispatch.dylib 0x00000001009d18ac _dispatch_client_callout + 16
25 libdispatch.dylib 0x00000001009dde84 _dispatch_block_invoke_direct + 232
26 FrontBoardServices 0x0000000185ed6b04 <redacted> + 36
27 FrontBoardServices 0x0000000185ed67a8 <redacted> + 404
28 FrontBoardServices 0x0000000185ed6d44 <redacted> + 56
29 CoreFoundation 0x00000001837e0a80 <redacted> + 24
30 CoreFoundation 0x00000001837e0a00 <redacted> + 88
31 CoreFoundation 0x00000001837e0288 <redacted> + 204
32 CoreFoundation 0x00000001837dde60 <redacted> + 1048
33 CoreFoundation 0x00000001836ff9dc CFRunLoopRunSpecific + 436
34 GraphicsServices 0x000000018555cfac GSEventRunModal + 100
35 UIKit 0x000000018d360ef0 UIApplicationMain + 208
36 CrashDemo 0x000000010091c418 main + 124
37 libdyld.dylib 0x000000018321ea14 <redacted> + 4
);
defaultToDo = "This framework default is to ignore this operation to avoid crash.";
errorName = NSRangeException;
errorPlace = "Error Place:-[ViewController viewDidLoad]";
errorReason = "*** -[__NSArrayM setObject:atIndexedSubscript:]: index 1 beyond bounds for empty array";
exception = "*** -[__NSArrayM setObject:atIndexedSubscript:]: index 1 beyond bounds for empty array";
}
这个信息通过正则表达式处理,可以获取到自己想要的信息,包括造成崩溃的方法,具体位置.
我的这个处理方法是从chenfanfang那里copy的
个人感觉在crash的处理方面用起来还是很方便的,有时候需要在APP内做统计事件,比如点击,比如页面的进入次数,这些其实可以通过在项目初期创建个很好的基类容器来实现,但是如果后期加入,并且初期的基类并没有很好的构造,这个时候就会发现runtime有很大的用处.
这篇文章其实主要就是用代码来展示,主要原因还是作者很少写文章,也不太会措辞,哈哈哈.
统计页面进入示例
可以通过改写系统的- (void)viewWillAppear:(BOOL)animated 方法.
#import "Statistics+ViewController.h"
#import <objc/runtime.h>
@implementation UIViewController (Statistics_ViewController)
+(void)load
{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Method originalMethod = class_getInstanceMethod([self class], @selector(viewWillAppear:));
Method swizzledMethod = class_getInstanceMethod([self class], @selector(KviewWillAppear:));
method_exchangeImplementations(originalMethod, swizzledMethod);
});
}
- (void)KviewWillAppear:(BOOL)animated
{
[self KviewWillAppear:animated];
NSLog(@"进入%@",[self class]);
}
拦截tableview的点击方法
tableview点击方法因为是tableViewDelegate的方法,所以交换方法要先交换系统的Delegate方法,交换成功后再交换Cell的DidSelect方法.
#import "DJ+TableView.h"
#import <objc/runtime.h>
#import <objc/message.h>
@implementation UITableView (DJ_TableView)
+ (void)load
{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Method originalMethod = class_getInstanceMethod(self, @selector(setDelegate:));
Method swizzledMethod = class_getInstanceMethod(self, @selector(DJsetDelegate:));
BOOL didAddMethod =
class_addMethod(self,
@selector(setDelegate:),
method_getImplementation(swizzledMethod),
method_getTypeEncoding(swizzledMethod));
if (didAddMethod) {
class_replaceMethod(self,
@selector(DJsetDelegate:),
method_getImplementation(originalMethod),
method_getTypeEncoding(originalMethod));
}
else {
method_exchangeImplementations(originalMethod, swizzledMethod);
}
});
}
- (void)DJsetDelegate:(id<UITableViewDelegate>)delegate
{
[self DJsetDelegate:delegate];
if (class_addMethod([delegate class], NSSelectorFromString(@"DJdidSelectRowAtIndexPath"), (IMP)DJdidSelectRowAtIndexPath, "v@:@@")) {
Method didSelectOriginalMethod = class_getInstanceMethod([delegate class], NSSelectorFromString(@"DJdidSelectRowAtIndexPath"));
Method didSelectSwizzledMethod = class_getInstanceMethod([delegate class], @selector(tableView:didSelectRowAtIndexPath:));
method_exchangeImplementations(didSelectOriginalMethod, didSelectSwizzledMethod);
}
}
void DJdidSelectRowAtIndexPath(id self, SEL _cmd, id tableView, id indexPath)
{
SEL selector = NSSelectorFromString(@"DJdidSelectRowAtIndexPath");
((void(*)(id, SEL, id, id))objc_msgSend)(self, selector, tableView, indexPath);
NSLog(@"点击了");
}
@end
runtime虽然很多人感觉是动用了系统层的语法,怕在使用过程中遇到未知的问题,但是我在使用过程中感觉还是利大于弊,需要对全局进行操作的时候方便很多.并且runtime所对应的AOP编程方式,也更适用于做这种架构的编程.
