检查图片大小并自动适应控件宽度

Js：

function changeSize()
        {
            // 获取装所有图片内容控件对象
            var pObj = document.getElementById('<%=Panel3.ClientID %>');
            
            // 获取控件对象的宽度
            if (pObj != null && typeof(pObj) != "undefined")
            {
                var pWidth = pObj.style.width;  // 控件宽度200pt
                pWidth = pWidth.substring(0,pWidth.indexOf("p"));  //200
                
                // 获取所有img对象
                var img = pObj.getElementsByTagName("img");
                if (img != null && typeof(img) != "undefined" && img.length >0)
                {
                    // check图片size
                    for (var i = 0; i< img.length;i++){
                        if (img[i].width > pWidth)  //判断是否大于控件宽度
                        {
                            img[i].style.width =  pWidth + "pt";  // 控件宽度赋予img对象
                        }
                    }
                }
            }
        }

后台注册js：

 Page.ClientScript.RegisterStartupScript(
                this.GetType(),
                "changeSize",
                "changeSize();",
                true);