1

//时间间隔
    NSTimeInterval textFieldDidChangeInterval;
    //定时器
    NSTimer *_timer;

- (void)textTimer_search:(UITextField*)textField{
    NSTimeInterval start =CACurrentMediaTime();
    if (start -textFieldDidChangeInterval <1.0) {
        textFieldDidChangeInterval = start;
        [_timer invalidate];
        _timer = nil;
        _timer = [NSTimer scheduledTimerWithTimeInterval:1.0 repeats:NO block:^(NSTimer * _Nonnull timer) {
            [self req_searchList:textField.text];
        }];
        [[NSRunLoop currentRunLoop] addTimer:_timer forMode:NSDefaultRunLoopMode];
    }else{
        textFieldDidChangeInterval = start;
        //发起请求获取数据
        [self req_searchList:textField.text];
    }
}