由于之前做項目的時候，時不時會有無法預(yù)見的錯誤谈为，導(dǎo)致App上線了旅挤，Crash的時候，用戶體驗非常不好伞鲫。查過各方面的資料后粘茄，決定把這些無法預(yù)見的Crash給解決的，至少先保證App能正常用秕脓。

想了下柒瓣，其實也不難，就是對NSString吠架、NSMutableString芙贫、NSArray、NSMutableArray傍药、NSDictionary磺平、NSMutableDictionary、KVO 這些常用的類方法做了方法替換拐辽，數(shù)組索引越界褪秀、字典數(shù)據(jù)對象為nil的異常處理

@implementation NSArray (GJNoCrash)
void array_method_exchangeImplementations(Class cls, SEL name, SEL name2) {
    
    Method fromMethod = class_getInstanceMethod(cls, name);
    Method toMethod = class_getInstanceMethod(cls, name2);
    method_exchangeImplementations(fromMethod, toMethod);
}

+ (void)load
{
    Class __NSArray     = objc_getClass("NSArray");
    Class __NSArrayI    = objc_getClass("__NSArrayI");
    Class __NSArray0    = objc_getClass("__NSArray0");
    Class __NSSingleObjectArrayI = objc_getClass("__NSSingleObjectArrayI");
    
    array_method_exchangeImplementations(__NSArray, @selector(arrayWithObjects:count:), @selector(safeArrayWithObjects:count:));
    array_method_exchangeImplementations(__NSArray, @selector(objectsAtIndexes:), @selector(safeObjectsAtIndexes:));
    array_method_exchangeImplementations(__NSArrayI, @selector(objectAtIndexedSubscript:), @selector(safeObjectAtIndexedSubscript:));
    array_method_exchangeImplementations(__NSArray0, @selector(objectAtIndex:), @selector(safeObjectAtIndexedNullarray:));
    array_method_exchangeImplementations(__NSSingleObjectArrayI, @selector(objectAtIndex:), @selector(safeObjectAtIndexedArrayCountOnlyOne:));
    
    array_method_exchangeImplementations(__NSArray, @selector(getObjects:range:), @selector(safeGetObjectsArray:range:));
    array_method_exchangeImplementations(__NSArrayI, @selector(getObjects:range:), @selector(safeGetObjectsArrayI:range:));
    array_method_exchangeImplementations(__NSSingleObjectArrayI, @selector(getObjects:range:), @selector(safeGetObjectsNSSingleObjectArrayI:range:));
    
}

- (instancetype)safeArrayWithObjects:(const id  _Nonnull __unsafe_unretained *)objects count:(NSUInteger)cnt
{
    id instance = nil;
    
    @try {
        instance = [self safeArrayWithObjects:objects count:cnt];
    }
    @catch (NSException *exception) {
        
        //以下是對錯誤數(shù)據(jù)的處理，把為nil的數(shù)據(jù)去掉,然后初始化數(shù)組
        NSInteger newObjsIndex = 0;
        id  _Nonnull __unsafe_unretained newObjects[cnt];
        
        for (int i = 0; i < cnt; i++) {
            if (objects[i] != nil) {
                newObjects[newObjsIndex] = objects[i];
                newObjsIndex++;
            }
        }
        instance = [self safeArrayWithObjects:newObjects count:newObjsIndex];
    }
    @finally {
        return instance;
    }
}
@end

大概原理就是這樣

常見異常

NSString *s = @"aa";
NSString *ss = [s substringFromIndex:10];
NSLog(@"ss:%@", ss);
        
NSMutableString *s = [NSMutableString stringWithFormat:@"aaaa"];
NSString *ss = [s stringByReplacingCharactersInRange:NSMakeRange(10, 10) withString:@"bb"];
NSLog(@"ss:%@", ss);
        
NSArray *a = [NSArray array];
id v = [a objectAtIndex:10];
NSLog(@"array index 10 :%@", v);
        
NSMutableArray *array = [NSMutableArray array];
[array addObject:nil];
NSLog(@"NSMutableArray:%@", array);
        
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
[dict setObject:nil forKey:@"key1"];
[dict setObject:@"value1" forKey:nil];
[dict setObject:@"value2" forKey:@"key2"];
NSLog(@"NSMutableDictionary:%@", dict);

我把這些整合發(fā)布到pod上去了薛训。

pod search GJNoCrash

Crash log 處理有兩種方式

#import "GJCrashLog.h"
//方法1 block方法
[[GJCrashLog manager] callbackCrashLog:^(NSString *crashLog) {
          //處理crashlog
}];

//方法2 delegate方式
[GJCrashLog manager].delegate = self;
//GJCrashLog Delegate
-(void)callbackGJCrashLog:(NSString *)crashLog
{
    //處理crashlog
}

github地址在這里