Question

我在JavaScript中运行一个函数，一旦激活就不会停止，我需要一种方法来完全停止这个功能及其所有内容和事件

line.addEventListener('click', function () {
   $(function(){

    var canvasOffset=$("#canvas").offset();
   var offsetX=canvasOffset.left;
  var offsetY=canvasOffset.top;
window.alert(offsetX);
    var startX;
    var startY;
    var isDown=false;
   var canvas2 = $("#canvas");



    function drawLine(toX,toY,context){
        context.beginPath();
        context.moveTo(startX, startY);
        context.lineTo(toX,toY);
        context.stroke();
    }

    function handleMouseDown(e){
      e.preventDefault();
      mouseX=parseInt(e.clientX-offsetX);
      mouseY=parseInt(e.clientY-offsetY);

      // save drag-startXY, 
      // move temp canvas over main canvas,
      // set dragging flag
      startX=mouseX;
      startY=mouseY;
      contextTemp.clearRect(0,0,canvasTemp.width,canvasTemp.height);
      $("#canvasTemp").css({ left:0, top:0 });
      isDown=true;
    }

    function handleMouseUp(e){
      e.preventDefault();
      if(!isDown){return;}
      // clear dragging flag
      // move temp canvas offscreen
      // draw the user's line on the main canvas
      isDown=false;
      mouseX=parseInt(e.clientX-offsetX);
      mouseY=parseInt(e.clientY-offsetY);

      drawLine(mouseX,mouseY,context);
    }

    function handleMouseMove(e){
      e.preventDefault();        
      if(!isDown){return;}
      mouseX=parseInt(e.clientX-offsetX);
      mouseY=parseInt(e.clientY-offsetY);
      // clear the temp canvas
      // on temp canvas draw a line from drag-start to mouseXY
      contextTemp.clearRect(0,0,canvasTemp.width,canvasTemp.height);
      drawLine(mouseX,mouseY,contextTemp);
    }

  canvas2.mousedown(function(e){handleMouseDown(e);});
    canvas2.mousemove(function(e){handleMouseMove(e);});
  canvas2.mouseup(function(e){handleMouseUp(e);});
 canvas2.mouseout(function(e){handleMouseUp(e);});


}); // end $(function(){});
});

此功能需要停止在变量点击上运行，例如停止按钮

但它无法阻止所有其他正在运行的功能

Answer 1

为什么不解开你在第一时间设置的事件，因为你已经使用了jQuery，你可以做sg。像：

var handleMouseDown = function(e) {
  /* ... */
};

// bind the event:
$( "#canvas" ).bind( "click", handler );

// unbind again:
$( "#canvas" ).unbind( "click", handler );

删除功能：

 var fn = function() {
     alert( 1 );
 }
 fn();
 fn = undefined;
 fn();

结束JavaScript函数及其所有内容

1 个答案: