IOS Capture Program exception

In the development of IOS , we will encounter the case that the program throws an abnormal exit, and if it is in the process of debugging, the information of the exception is clear at a glance, but it is sometimes difficult to get the information of the exception in the published program.

IOS provides an exception to the processing API, we can add such a Handlerwhen the program starts, such a program when an exception can be done in this part of the information to do the necessary processing, Timely feedback to the developer.

First define a class Signalhandler

@interface signalhandler: nsobject

+ (instancetype) Instance;

-(void) Setexceptionhandler;

@end

Implement SIGNALHANDLER.M

#import "SignalHandler.h"

#import <UIKit/UIKit.h>

#include <libkern/OSAtomic.h>

#include <execinfo.h>

@interface signalhandler ()

{

BOOL isdismissed;

}

-(void) HandleException1: (nsexception *) exception;

@end

callback function after capturing the signal

void handleexception (nsexception *exception)

{

// handling exception messages

[[signalhandler Instance] performselectoronmainthread:@selector( HandleException1:) withobject: Exception waituntildone:YES];

}

@implementation Signalhandler

Static signalhandler *s_signalhandler = nil;

+ (instancetype) instance{

static dispatch_once_t oncetoken;

dispatch_once(&oncetoken, ^{

if (s_signalhandler = = Nil) {

S_signalhandler = [[signalhandler alloc] init];

}

});

return s_signalhandler;

}

-(void) Setexceptionhandler

{

Nssetuncaughtexceptionhandler(&handleexception);

}

methods used to handle exceptions

-(void) HandleException1: (nsexception *) exception

{

cfrunloopref runloop = cfrunloopgetcurrent();

cfarrayref allmodes = cfrunloopcopyallmodes(runloop);

// exception stack information

nsarray *stackarray = [exception callstacksymbols];

// Causes of anomalies

nsstring *reason = [exception reason];

// exception name

nsstring *name = [exception name];

nsstring *exceptioninfo = [nsstring stringwithformat:@ " cause:%@\n Name:%@\ N Stacks:%@ ", name, Reason, Stackarray];

NSLog(@ "%@", exceptioninfo);

    // Here you can also save file

uialertview *alertview = [[uialertview alloc] initwithtitle:@ "There's a problem with the program. " message: Exceptioninfo delegate:self cancelbuttontitle:@" Cancel " otherbuttontitles:nil";

[Alertview show];

// when receiving an exception handling message, let the program start runloopto prevent the program from dying

while (! Isdismissed) {

for (nsstring *mode in (__bridge nsarray *) allmodes)

{

Cfrunloopruninmode((cfstringref) mode, 0.001, false);

}

}

// when clicking the Cancel button of the popup view Oh , isdimissed = Yes, the top loop jumps out

cfrelease(allmodes);

Nssetuncaughtexceptionhandler(NULL);

}

-(void) Alertview: (uialertview *) Analertview clickedbuttonatindex: (nsinteger) anindex

{

// because this pop-up view has only one Cancel button, the isdimsmissed variable is modified directly.

isdismissed = YES;

}

Finally, you need to

Add in Didfinishlaunchingwithoptions

[[signalhandler Instance] setexceptionhandler];

Once you're done, you can verify it and add the following code

nsarray *array = [nsarray arraywithobjects:@ "1", Nil];

[Array objectatindex:2];

IOS Capture Program exception