enumerateObjectsUsingBlock

//對數組中元素塊操作
    NSArray* array = @[@"aa",@"bb",@"cc",@"dd",@"ee",@"ff",@"gg"];
    [array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        NSLog(@"%@",obj);
    }];
    NSLog(@"-------------- ");
    //NSIndexSex 是取值范圍  options為NSEnumerationReverse倒序，NSEnumerationConcurrent正序
    [array enumerateObjectsAtIndexes:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(1, 4)] options:NSEnumerationReverse usingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        NSLog(@"%@",obj);
    }];
    NSLog(@"-----enumerateObjectsUsingBlock--------- ");
    _textfield1 = [[UITextField alloc]init];
    _textfield2 = [[UITextField alloc]init];
    _textfield3 = [[UITextField alloc]init];
    _textfield4 = [[UITextField alloc]init];
    _textfield5 = [[UITextField alloc]init];
    _textfield6 = [[UITextField alloc]init];
    NSArray* textfieldArray = @[_textfield1,_textfield2,_textfield3,_textfield4,_textfield5,_textfield6];
    //可以利用此方法進行控件批量處理，不過不能進行創建處理，因為Array會報插入null元素的錯。
    [textfieldArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        UITextField* textfield = obj;
        NSLog(@"%i",idx);
        textfield.tag = idx;
        textfield.text = [array objectAtIndex:idx];
        NSLog(@"%@",textfield.text);
        textfield.delegate = self;
    }];
    NSLog(@"text3 : %@",_textfield3.text);
    NSLog(@"-------indexOfObjectPassingTest------- ");
    //可以處理自己想要的元素，參數方法同上類似
    NSInteger index = [textfieldArray indexOfObjectPassingTest:^BOOL(id obj, NSUInteger idx, BOOL *stop) {
        UITextField* textfield = (UITextField*)obj;
        NSLog(@"%i",textfield.tag);
        NSLog(@"%@",textfield.text);
        if([textfield.text isEqualToString:@"cc"]){
            return YES;
        }
        return NO;
    }];
    NSLog(@"%i\n------------------------",index);