滑动手势到滑动uiviews

Question

我想做滑动手势以滑动 UIView 连续获取数据。考虑每个单词 UIView. 。我将数据存储在数组中，并以标签印刷 UIView 在过渡时。但是，当我尝试滑动后，显示所有数据程序都停止工作。我的项目没有显示错误。请帮助我。

这是我的数组：

addArray = [[NSMutableArray alloc]initWithCapacity:4];
[addArray insertObject:@"10" atIndex:0];
[addArray insertObject:@"20" atIndex:1];
[addArray insertObject:@"30" atIndex:2];
[addArray insertObject:@"40" atIndex:3];

flippedArray = [[NSMutableArray alloc] initWithCapacity:4];
[flippedArray insertObject:@"100" atIndex:0];
[flippedArray insertObject:@"200" atIndex:1];
[flippedArray insertObject:@"300" atIndex:2];
[flippedArray insertObject:@"400" atIndex:3];

这是我的手势识别器编码：

-(void)swipegesture:(UISwipeGestureRecognizer *)recognizer{

    CGPoint location = [recognizer locationInView:additionalView];   
    if (recognizer.direction==UISwipeGestureRecognizerDirectionLeft) 
    {
        if (increment<[addArray count]) 
        {
            NSLog(@"%d",[addArray count]);
            increment++;
            if(increment==[addArray count])
            {
                NSLog(@"Fail");
                //[recognizer requireGestureRecognizerToFail:swipeGesture];
                [recognizer setEnabled:NO];
            }
            else
            {
                additionalLabel.text=[[NSString alloc] initWithFormat:@"%@",
                                         [addArray objectAtIndex:increment]];
                flippedLabel.text = [[NSString alloc] initWithFormat:@"%@",
                                         [flippedArray objectAtIndex:increment]];
                NSLog(@"increment %d",increment);
                [UIView animateWithDuration:0.55 animations:^{
                    [UIView setAnimationDelay:0.2];
                }];
                CATransition *animation = [CATransition animation];
                [animation setType:kCATransitionPush];
                [animation setSubtype:kCATransitionFromRight];
                [animation setTimingFunction:[CAMediaTimingFunction
                               functionWithName:kCAMediaTimingFunctionDefault]];
                [animation setSpeed:0.4];
                [[additionalView  layer] addAnimation:animation forKey:nil];
            }
        }
    }
    else if(recognizer.direction==UISwipeGestureRecognizerDirectionRight)
    {
        if (increment>=0 && increment<[addArray count]) 
        {
            increment--;
            if(increment>[addArray count])
            {
                additionalLabel.text=[[NSString alloc]initWithFormat:@"%@",
                                         [addArray objectAtIndex:increment]];
                flippedLabel.text=[[NSString alloc]initWithFormat:@"%@",
                                      [flippedArray objectAtIndex:increment]];
                NSLog(@"Decrement %d",increment);
                [UIView animateWithDuration:0.55 animations:^{
                    [UIView setAnimationDelay:0.2];
                }];
                CATransition *animation = [CATransition animation];
                [animation setType:kCATransitionPush];
                [animation setSubtype:kCATransitionFromLeft];
                [animation setTimingFunction:[CAMediaTimingFunction 
                               functionWithName:kCAMediaTimingFunctionDefault]];
                [animation setSpeed:0.4];
                [[additionalView layer] addAnimation:animation forKey:nil];
            }
        }
    }
}

有一个问题，而仅增量。我有 NSLog 打印为失败。但是如果达到价值为 [addArray count].

Answer 1

我建议在有效性检查之前递增或减少索引值（您命名为增量），如果没有有效的话，将您的操作反转为其他。像这样：

if (recognizer.direction==UISwipeGestureRecognizerDirectionLeft) 
{
    increment++;

    if (increment<[addArray count]) 
    {
        // Your code
    }
    else
    {
        increment--; // The increment would pass the range of the array, set it back.
    }
}

同样是另一个方向。

编辑：要澄清，最初的问题是您检查以确保索引有效，但是，通过在检查后递增您最终使其无效。使用您的示例，当增量为3（数组的最高索引）时，它实际上比数组计数少，即4.您将索引递增到4，或者在范围内，或者在您的中情况，属于IF语句（使用该建议将不再需要）并记录您的失败。