Question

我希望创建一个简单的调色板，并在界面构建器中设置按钮网格。

我希望用户能够通过选择任何按钮与调色板（按钮）进行交互，然后在按钮之间拖动手指（在进入和退出按钮时触发事件并在每个事件中更改所选颜色）。这可能吗？

例如，用户触摸蓝色按钮（颜色更新），然后将手指拖动到绿色按钮（颜色更新）。

“触摸拖动输入”和“触摸拖动退出”事件似乎仅在用户的初始选择位于发件人上时触发（不允许在两个按钮之间拖动）。谢谢！

Answer 1

我创建了一个简单的应用程序，可以满足您的需求。您可以在以下网址找到来源：

http://github.com/st3fan/iphone-experiments/tree/master/Miscellaneous/ColorPalette/

它只是一个容器视图（PaletteView），其中包含一组具有特定颜色的子视图。当PaletteView收到触摸后，它会找到触摸下的视图，然后告诉其委托（PaletteViewDelegate）颜色发生变化。

使用4.0.2在iPhone 4上测试。

Answer 2

您可以使用touchesBegan + touchesMoved + touchesEnded方法，从头到尾创建用户触摸的按钮列表。

我在飞行中写了这个并没有测试它，但它看起来像这样：

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{
    // interactions is the NSMutableArray where you store the pressed/dragged buttons
    // we need to clear it when we start a new checkForInteractions
    [interactions removeAllObjects];

    UITouch *touch = [touches anyObject];
    [self checkForInteractions:touch];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    [self checkForInteractions:touch];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    [self checkForInteractions:touch];
    // here you'd call a function that'd use the buttons on the array,
    // to do whatever you wanted with them
    // it can also be copied to touchesMoved, to trigger the interactions
    // as the user's finger is moving, rather than only when it stops
    [self useInteractions];
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event 
{
    // if the touch was cancelled, clear the interactions
    [interactions removeAllObjects];
}
- (void) checkForInteractions : (UITouch *) touch
{
    if ([touch view] == myButton1 || [touch view] == myButton2)
    {
        // check if the object had already been added to the array
        if ( ![interactions containsObject:[touch view]] )
        {
            [interactions addObject:[touch view]];
        }
    }
}

我希望这会有所帮助：）

Answer 3

我想你可能会对UIGestureRecognizer

感到幸运

iPhone上可以拖动的按钮网格

3 个答案: