varstartx=0,starty=0,endx=12,endy=100;for(startx;startx预期输出:0,12,0,1000,12,1,1000,12,2,100...0,12,100,1001,12,0,1001,12,1,100...12,12,100,100;EOOChrome39+上的输出0,12,0,1000,12,1,1000,12,2,100...0,12,100,100所以问题是第一个for循环没有遍历startx变量。你能告诉我为什么它不迭代吗? 最佳答案 那是一个有趣的谜题。我花了几次才捕获它。
我有一些函数可以在Canvas元素上绘制矩形。绘制元素时,我希望能够通过拖动它的Angular来调整它的大小。varcanvas=document.getElementById('canvas'),ctx=canvas.getContext('2d'),rect={},drag=false;functioninit(){canvas.addEventListener('mousedown',mouseDown,false);canvas.addEventListener('mouseup',mouseUp,false);canvas.addEventListener('mousemov
我有一些函数可以在Canvas元素上绘制矩形。绘制元素时,我希望能够通过拖动它的Angular来调整它的大小。varcanvas=document.getElementById('canvas'),ctx=canvas.getContext('2d'),rect={},drag=false;functioninit(){canvas.addEventListener('mousedown',mouseDown,false);canvas.addEventListener('mouseup',mouseUp,false);canvas.addEventListener('mousemov