Question

我只是一个菜鸟，我似乎无法找到错误。它是用于缩放，旋转和移动UIImageView的一段代码。我可以移动UIImageView但是当我尝试旋转或缩放UIImageView时它只会崩溃。我确实将setMultipleTouchEnabled设置为YES。

崩溃是因为：[NSArray objectAtIndex:]: index 1 beyond bounds [0 .. 0]

我认为错误出现在文本的这一部分：

    - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    NSArray *allTouches = [touches allObjects];

    UITouch* t;
    if([[event allTouches] count]==1){
        if (CGRectContainsPoint([Birdie frame], [[allTouches objectAtIndex:0] locationInView:self.view])) {
            t=[[[event allTouches] allObjects] objectAtIndex:0];
            touch1=[t locationInView:nil];
        }
    }else{
        t=[[[event allTouches] allObjects] objectAtIndex:0];
        touch1=[t locationInView:nil];
        t=[[[event allTouches] allObjects] objectAtIndex:1];
        touch2=[t locationInView:nil];
    }
}

-(double)distance:(CGPoint)point1 toPoint:(CGPoint)point2
{
    double deltaX, deltaY;
    deltaX = point1.x - point2.x;
    deltaY = point1.y - point2.y;
    return sqrt(deltaX * deltaX + deltaY * deltaY);
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

    CGPoint currentTouch1;
    CGPoint currentTouch2;
    NSArray *allTouches = [touches allObjects];
    UITouch* t;
    float scale,rotation;

    if([[event allTouches] count]==1){
        t=[[[event allTouches] allObjects] objectAtIndex:0];
        if (CGRectContainsPoint([Birdie frame], [[allTouches objectAtIndex:0] locationInView:self.view]))
        { 
            touch2=[t locationInView:nil];
            Birdie.center=CGPointMake(Birdie.center.x+touch2.x-touch1.x,Birdie.center.y+touch2.y-touch1.y);
            touch1=touch2;
        }
    }
    else if([[event allTouches] count]==2)
    {
        t=[[[event allTouches] allObjects] objectAtIndex:0];
        currentTouch1=[t locationInView:nil];

        t=[[[event allTouches] allObjects] objectAtIndex:1];
        currentTouch2=[t locationInView:nil];

        double distance1 =  [self distance:currentTouch1 toPoint:currentTouch2];
        double distance2 = [self distance:touch1 toPoint:touch2];

        if (distance2 == 0)
        {
            //handle the case where distance is zero
        }
        else {
            scale =distance1 / distance2;}

        rotation=atan2(currentTouch2.y-currentTouch1.y, currentTouch2.x-currentTouch1.x)-atan2(touch2.y-touch1.y,touch2.x-touch1.x);
        if(isnan(scale)){
            scale=1.0f;
        }
        NSLog(@"rotation %f",rotation);

        NSLog(@"scale %f",scale);

        if (CGRectContainsPoint([Birdie frame], [[allTouches objectAtIndex:0] locationInView:self.view]) &&
            CGRectContainsPoint([Birdie frame], [[allTouches objectAtIndex:1] locationInView:self.view]))
        {

            Birdie.transform=CGAffineTransformScale(Birdie.transform, scale,scale);
            Birdie.transform=CGAffineTransformRotate(Birdie.transform, rotation);
        }
        else // In case of scaling or rotating the background imageView
        {
            imageView.transform=CGAffineTransformScale(imageView.transform, scale,scale);
            imageView.transform=CGAffineTransformRotate(imageView.transform, rotation);
        }

        touch1=currentTouch1;
        touch2=currentTouch2;
    }
}

先谢谢！

Answer 1

当您拨打此电话时：

  if (CGRectContainsPoint([Birdie frame], [[allTouches objectAtIndex:0] locationInView:self.view]) &&
            CGRectContainsPoint([Birdie frame], [[allTouches objectAtIndex:1] locationInView:self.view]))

确保allTouches中确实有两个触摸对象。

Answer 2

如果您正在使用the table tableview，请记住设置：

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{
   if(tableview == self.table1)
    {
      return [mydictionaryObject count]; 
    }

}

错误消息：“索引1超出范围”

2 个答案: