NSMutableArray数组越界崩溃解决
对一个可变数组操作很频繁，并且在多个线程操作同一个可变数组时，发生数组越界等崩溃是很常见的。所以使用runtime swizzle ，对其方法进行交换。然后在交换方法中对增,删,改,查等做保护机制就可以避免数组越界造成的崩溃。
1.新建一个NSMutableArray的分类
#import
NS_ASSUME_NONNULL_BEGIN
@interfaceNSMutableArray (SafeMutableArray)
@end
NS_ASSUME_NONNULL_END
2.文件实现
需要导入runtime.h文件
#import<objc/runtime.h>
然后在load方法中声明进行方法交换声明
+ (void)load
{
staticdispatch_once_tonceToken;
dispatch_once(&onceToken, ^{
idobj = [[selfalloc]init];
[objswizzleInstanceMethod:@selector(addObject:)withMethod:@selector(m_addObject:)];
[objswizzleInstanceMethod:@selector(objectAtIndex:)withMethod:@selector(m_objectAtIndex:)];
});
}
交换方法的实现
- (void)swizzleInstanceMethod:(SEL)origSelector withMethod:(SEL)newSelector {
Classcls = [selfclass];
MethodoriginalMethod =class_getInstanceMethod(cls, origSelector);
MethodswizzledMethod =class_getInstanceMethod(cls, newSelector);
BOOLdidAddMethod =class_addMethod(cls,
origSelector,
method_getImplementation(swizzledMethod),
method_getTypeEncoding(swizzledMethod));
if(didAddMethod) {
class_replaceMethod(cls,
newSelector,
method_getImplementation(originalMethod),
method_getTypeEncoding(originalMethod));
}else{
method_exchangeImplementations(originalMethod, swizzledMethod);
}
}
- (void)m_addObject:(id)anObject
{
if(nil!= anObject) {
[selfm_addObject:anObject];
}
else
{
NSLog(@"这虽然是空数据，但是不会crash");
}
}
- (id)m_objectAtIndex:(NSUInteger)index
{
if(index
return[selfm_objectAtIndex:index];
}
else
{
NSLog(@"虽然数组越界，但是不会crash");
returnnil;
}
}
