Html 如何在IE 11中检测指针事件的手指计数
我已经为canvas对象实现了指针事件。我需要知道如何检测触摸事件的手指计数。下面是我的一段代码:Html 如何在IE 11中检测指针事件的手指计数,html,internet-explorer,internet-explorer-11,pointer-events,Html,Internet Explorer,Internet Explorer 11,Pointer Events,我已经为canvas对象实现了指针事件。我需要知道如何检测触摸事件的手指计数。下面是我的一段代码: canvasObj.addEventListener('pointerenter',mouseEnterCall,false); canvasObj.addEventListener('pointerdown',mouseDownCall,false); canvasObj.addEventListener('pointermove',mouseMoveCall,false); canvasObj
canvasObj.addEventListener('pointerenter',mouseEnterCall,false);
canvasObj.addEventListener('pointerdown',mouseDownCall,false);
canvasObj.addEventListener('pointermove',mouseMoveCall,false);
canvasObj.addEventListener('pointerup',mouseUpCall,false);
canvasObj.addEventListener('pointerout',mouseOutCall,false);
谢谢你的帮助 屏幕上没有提供当前手指数(活动指针)的内置属性。但这里有一些简单的代码可以实现这一点:
var pointerCount = 0; //Stores current number of "active pointers"
window.addEventListener("pointerdown", addPointer, true);
window.addEventListener("pointerup", removePointer, true);
window.addEventListener("pointercancel", removePointer, true);
function addPointer(e) { pointerCount++ }
function removePointer(e) { pointerCount-- }
如果需要,可以修改addPointer以仅计数触摸指针:
function addPointer(e) { if (e.pointerType === "touch") pointerCount++ }
请注意,如果您还想支持IE10,则需要对该代码进行一些修改,IE10具有该标准的早期(前缀)版本。下面是一段代码。canvasObj.addEventListener('pointerenter',mouseEnterCall,false);canvasObj.addEventListener('pointerdown',mouseDownCall,false);canvasObj.addEventListener('pointermove',mouseMoveCall,false);canvasObj.addEventListener('pointerup',mouseUpCall,false);canvasObj.addEventListener('pointerout',mouseOutCall,false);很抱歉给你带来了困惑。我正在尝试使用上述模型检测IE11浏览器上的手指计数。有可能吗?或者有其他方法吗?我想我在这里找到了答案。