iOS如何解决某些方法低版本不支持的问题

来源：互联网发布：php 数组写法编辑：程序博客网时间：2024/05/01 04:14

#import "NSString+avoidCrash.h"#import <objc/runtime.h>@implementation NSString (avoidCrash)+(void)load{    static dispatch_once_t onceToken;    dispatch_once(&onceToken, ^{                SEL systemSel = @selector(containsString:);        Method systemMethod = class_getInstanceMethod([self class], systemSel);        //如果没有找到，说明不包含此方法，需要动态添加此方法        if (systemMethod == NULL) {            SEL customSel = @selector(customContainsString:);            Method customMethod = class_getInstanceMethod([self class], customSel);                        BOOL isAdd = class_addMethod(self, systemSel, method_getImplementation(customMethod), method_getTypeEncoding(customMethod));                        if (!isAdd) {                NSLog(@"%@ runtime add method 'customContainsString:' failed",NSStringFromClass([self class]));            }        }            });}-(BOOL)customContainsString:(NSString *)str{    NSRange range = [self rangeOfString:str];        if (range.location < self.length && range.length > 0) {        return YES;    }        return NO;}@end

在实际的开发过程当中，经常会遇到一些方法低版本不支持的问题，往往需要加很多判断，造成代码很多，程序很冗余，总而言之就是不爽。

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