この記事の例では、JavaScript を使用して水色のマウスドラッグ選択ボックスを実装する方法を説明します。皆さんの参考に共有してください。具体的な実装方法は以下の通りです。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <style type="text/css"> #rectBox { background:#CCFFFF; border:2px solid #0099FF; filter:alpha(opacity=30); opacity:0.3; position:absolute; } </style> <head> <title>一个鼠标选择框</title> <script type="text/javascript"> function Rect() { this.doc = document.documentElement; if(!this.doc) return; this.startX = ''; this.startY = ''; this.rect = null; rectSelf = this; } Rect.prototype.down = function(e) { var e = e?e:window.event; rectSelf.startX = e.clientX?e.clientX + document.body.scrollLeft:e.pageX; rectSelf.startY = e.clientY?e.clientY + document.body.scrollTop:e.pageY; rectSelf.showRect(true); } Rect.prototype.up = function(e) { rectSelf.rectBox.style.width = '0px'; rectSelf.rectBox.style.height = '0px'; rectSelf.showRect(false); } Rect.prototype.move = function(e) { if(rectSelf.rectBox) { var currentX = e.clientX?e.clientX + rectSelf.doc.scrollLeft:e.pageX; var currentY = e.clientY?e.clientY + rectSelf.doc.scrollTop:e.pageY; rectSelf.rectBox.style.width = Math.abs(currentX - rectSelf.startX) + 'px'; rectSelf.rectBox.style.height = Math.abs(currentY - rectSelf.startY) + 'px'; if(currentX - rectSelf.startX < 0) { rectSelf.rectBox.style.left = currentX + 'px'; } if(currentY - rectSelf.startY < 0) { rectSelf.rectBox.style.top = currentY + 'px'; } //document.title = "left:"+currentX + 'px '+"top:"+currentY + 'px '; } } Rect.prototype.showRect = function(bool) { if(bool) { if(!this.rectBox) { this.rectBox = document.createElement("div"); this.rectBox.id = "rectBox"; document.body.appendChild(this.rectBox); } this.rectBox.style.display = "block"; this.rectBox.style.left = this.startX + 'px'; this.rectBox.style.top = this.startY + 'px'; this.addEventListener(this.doc , 'mousemove' , this.move); } else { if(this.rectBox) { this.rectBox.style.display = "none"; } this.removeEventListener(this.doc , 'mousemove' , this.move); } } Rect.prototype.addEventListener = function(o,e,l) { if (o.addEventListener) { o.addEventListener(e,l,false); } else if (o.attachEvent) { o.attachEvent('on'+e,function() { l(window.event); }); } } Rect.prototype.removeEventListener = function(o,e,l) { if (o.removeEventListener) { o.removeEventListener(e,l,false); } else if (o.detachEvent) { o.detachEvent('on'+e,function() { l(window.event); }); } } window.onload = function() { var oRect = new Rect(); oRect.addEventListener(oRect.doc , 'mousedown' , oRect.down); oRect.addEventListener(oRect.doc , 'mouseup' , oRect.up); } </script> </head> <body> <h1>拖动你的鼠标就会出现选择框</h1> </body> </html>
この記事が皆様の JavaScript プログラミング設計に役立つことを願っています。