记得小时候,后台各种传,垃圾参数,各种空值,各种取空字典中的值,之前用空值来判断,但是太麻烦,而且不晓得具体是哪一个,所以后来找到一个神器。虽然有点暴力,但是能解决很打一部分的crash问题,后面再继续补充添加,各种的情况。
https://github.com/allenhsu/NSDictionary-NilSafe
#import <Foundation/Foundation.h>
@interface NSDictionary (NilSafe)
@end
@interface NSMutableDictionary (NilSafe)
@end
#import <objc/runtime.h>
#import "NSDictionary+NilSafe.h"
@implementation NSObject (Swizzling)
+ (BOOL)gl_swizzleMethod:(SEL)origSel withMethod:(SEL)altSel {
Method origMethod = class_getInstanceMethod(self, origSel);
Method altMethod = class_getInstanceMethod(self, altSel);
if (!origMethod || !altMethod) {
return NO;
}
class_addMethod(self,
origSel,
class_getMethodImplementation(self, origSel),
method_getTypeEncoding(origMethod));
class_addMethod(self,
altSel,
class_getMethodImplementation(self, altSel),
method_getTypeEncoding(altMethod));
method_exchangeImplementations(class_getInstanceMethod(self, origSel),
class_getInstanceMethod(self, altSel));
return YES;
}
+ (BOOL)gl_swizzleClassMethod:(SEL)origSel withMethod:(SEL)altSel {
return [object_getClass((id)self) gl_swizzleMethod:origSel withMethod:altSel];
}
@end
@implementation NSDictionary (NilSafe)
+ (void)load {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
[self gl_swizzleMethod:@selector(initWithObjects:forKeys:count:) withMethod:@selector(gl_initWithObjects:forKeys:count:)];
[self gl_swizzleClassMethod:@selector(dictionaryWithObjects:forKeys:count:) withMethod:@selector(gl_dictionaryWithObjects:forKeys:count:)];
});
}
+ (instancetype)gl_dictionaryWithObjects:(const id [])objects forKeys:(const id<NSCopying> [])keys count:(NSUInteger)cnt {
id safeObjects[cnt];
id safeKeys[cnt];
NSUInteger j = 0;
for (NSUInteger i = 0; i < cnt; i++) {
id key = keys[i];
id obj = objects[i];
if (!key || !obj) {
continue;
}
safeKeys[j] = key;
safeObjects[j] = obj;
j++;
}
return [self gl_dictionaryWithObjects:safeObjects forKeys:safeKeys count:j];
}
- (instancetype)gl_initWithObjects:(const id [])objects forKeys:(const id<NSCopying> [])keys count:(NSUInteger)cnt {
id safeObjects[cnt];
id safeKeys[cnt];
NSUInteger j = 0;
for (NSUInteger i = 0; i < cnt; i++) {
id key = keys[i];
id obj = objects[i];
if (!key || !obj) {
continue;
}
if (!obj) {
obj = [NSNull null];
}
safeKeys[j] = key;
safeObjects[j] = obj;
j++;
}
return [self gl_initWithObjects:safeObjects forKeys:safeKeys count:j];
}
@end
@implementation NSMutableDictionary (NilSafe)
+ (void)load {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Class class = NSClassFromString(@"__NSDictionaryM");
[class gl_swizzleMethod:@selector(setObject:forKey:) withMethod:@selector(gl_setObject:forKey:)];
[class gl_swizzleMethod:@selector(setObject:forKeyedSubscript:) withMethod:@selector(gl_setObject:forKeyedSubscript:)];
});
}
- (void)gl_setObject:(id)anObject forKey:(id<NSCopying>)aKey {
if (!aKey || !anObject) {
return;
}
[self gl_setObject:anObject forKey:aKey];
}
- (void)gl_setObject:(id)obj forKeyedSubscript:(id<NSCopying>)key {
if (!key || !obj) {
return;
}
[self gl_setObject:obj forKeyedSubscript:key];
}
@end