4

我有这个儿童绘画应用程序，它使用鼠标事件在图像上绘画。但是我需要将鼠标事件转换为触摸，以便它可以在 ipad 上工作。请有人可以解释我如何做到这一点。我的应用程序代码与此示例代码http://cool-php-tutorials.blogspot.co.uk/2011/05/simple-html5-drawing-app-with-saving.html非常相似。

PS我对javascript的了解不是高级的所以请如果你能告诉我工作代码或示例将是一个很大的帮助

我的鼠标事件代码如下。请可以将此功能从鼠标转换为触摸..请我从现在开始 2 天就被困在这里了.. :|

var clickX = new Array();
var clickY = new Array();
var clickDrag = new Array();

// binding events to the canvas
$('#drawingCanvas').mousedown(function(e){
  var mouseX = e.pageX - this.offsetLeft;
  var mouseY = e.pageY - this.offsetTop;

  paint = true; // start painting
  addClick(e.pageX - this.offsetLeft, e.pageY - this.offsetTop);

  // always call redraw
  redraw();
});

$('#drawingCanvas').mousemove(function(e){
  if(paint){
    addClick(e.pageX - this.offsetLeft, e.pageY - this.offsetTop, true);
    redraw();
  }
});

// when mouse is released, stop painting, clear the arrays with dots
$('#drawingCanvas').mouseup(function(e){
  paint = false;

  clickX = new Array();
  clickY = new Array();
  clickDrag = new Array();
});

// stop painting when dragged out of the canvas
$('#drawARobot').mouseleave(function(e){
  paint = false;
});


// The function pushes to the three dot arrays
function addClick(x, y, dragging)
{
  clickX.push(x);
  clickY.push(y);
  clickDrag.push(dragging);
}



// this is where actual drawing happens
// we add dots to the canvas


function redraw(){

  for(var i=0; i < clickX.length; i++)
  {  
    context.beginPath();
    if(clickDrag[i] && i){
      context.moveTo(clickX[i-1], clickY[i-1]);
     }else{
       context.moveTo(clickX[i]-1, clickY[i]);
     }
     context.lineTo(clickX[i], clickY[i]);
     context.closePath();
     context.stroke();
  }
}
4

4 回答 4

9

你可以像这样映射它：

$('#drawingCanvas').bind("mousedown touchstart", function(e){

$('#drawingCanvas').bind("mousemove touchmove", function(e){

$('#drawingCanvas').bind("mouseup touchend", function(e){

如果需要，可以微调代码。

于 2013-07-12T11:18:25.197 回答
2

试试这个：

注意：您需要 jquery 库。

touchmouse.js

(function() {

    /* == GLOBAL DECLERATIONS == */
    TouchMouseEvent = {
        DOWN: "touchmousedown",
        UP: "touchmouseup",
        MOVE: "touchmousemove"
    }

    /* == EVENT LISTENERS == */
    var onMouseEvent = function(event) {
        var type;

        switch (event.type) {
            case "mousedown": type = TouchMouseEvent.DOWN; break;
            case "mouseup":   type = TouchMouseEvent.UP;   break;
            case "mousemove": type = TouchMouseEvent.MOVE; break;
            default: 
                return;
        }

        var touchMouseEvent = normalizeEvent(type, event, event.pageX, event.pageY);      
        $(event.target).trigger(touchMouseEvent); 
    }

    var onTouchEvent = function(event) {
        var type;

        switch (event.type) {
            case "touchstart": type = TouchMouseEvent.DOWN; break;
            case "touchend":   type = TouchMouseEvent.UP;   break;
            case "touchmove":  type = TouchMouseEvent.MOVE; break;
            default: 
                return;
        }

        var touch = event.originalEvent.touches[0];
        var touchMouseEvent;

        if (type == TouchMouseEvent.UP) 
            touchMouseEvent = normalizeEvent(type, event, null, null);
        else 
            touchMouseEvent = normalizeEvent(type, event, touch.pageX, touch.pageY);

        $(event.target).trigger(touchMouseEvent); 
    }

    /* == NORMALIZE == */
    var normalizeEvent = function(type, original, x, y) {
        return $.Event(type, {
            pageX: x,
            pageY: y,
            originalEvent: original
        });
    }

    /* == LISTEN TO ORIGINAL EVENT == */
    var jQueryDocument = $(document);

    if ("ontouchstart" in window) {
        jQueryDocument.on("touchstart", onTouchEvent);
        jQueryDocument.on("touchmove", onTouchEvent);
        jQueryDocument.on("touchend", onTouchEvent); 
    } else {
        jQueryDocument.on("mousedown", onMouseEvent);
        jQueryDocument.on("mouseup", onMouseEvent);
        jQueryDocument.on("mousemove", onMouseEvent);
    }

})();

html 页面 (index.html)

<!DOCTYPE html>
<html>
    <head>
        <title>touch</title>

        <meta http-equiv="Content-Type" content="text/html;charset=utf8" />
        <meta name="author" content="AUTHOR" />
        <meta name="keyword" content="KEYWORD" />
        <meta name="description" content="DESCRIPTION" />
        <script type="text/javascript" src="jquery.min.js"></script><!-- Please Download the jquery library -->
        <script type="text/javascript" src="touchmouse.js"></script>
        <script type="text/javascript">
        $(function(){
                var startdrag= false;
             $("#a").on(TouchMouseEvent.DOWN, function(){
                startdrag= true;
                move();

             });
             function move(){

                 $("#a").on(TouchMouseEvent.MOVE, function(e){
                    if(startdrag){
                    $(this).css('left',(e.pageX-50)) ;
                    $(this).css('top',(e.pageY-50));
                 }
                 });

            }
             $("#a").on(TouchMouseEvent.UP, function(e){
                startdrag= false;

             });

        });
        </script>

    </head>
    <body>
        <div id ="a" style="display:block;position:absolute;width:100px;height:100px;background:red;" ></div>
    </body>
</html>

这在安卓手机上对我有用。

于 2013-07-12T11:29:52.080 回答
1

鼠标和触摸事件的问题是它们没有相同的 api，

所以你需要规范化 api 以同时具有鼠标和触摸输入。

有一些解决方案，例如：

而且锤子代码非常好用：

var hamme = $("#myCanvas").hammer();

hammer.on("touch", function(e){     
   e.gesture.center.pageX;
    // ..
});

hammer.on("drag", function(e){
    e.gesture.center.pageX
   //..
})
于 2013-07-12T11:19:49.227 回答
0

你也可以试试——jQuery UI Touch Punch

点击这里

于 2013-07-12T11:32:42.660 回答