Extjs 图片的自动缩放

function resizeImage(obj)
{
    var width = Ext.getCmp(‘welcome‘).getWidth();  //welcome 为一Panel的id  分割线下的代码
    var height=Ext.getCmp(‘welcome‘).getHeight();
    obj.width=width;
    obj.height=height;
}
...
{
            id:‘welcome‘,
            title: ‘首页‘,
            html:‘<img id="back" src="../../images/background.png" onload="resizeImage(this)"/>‘,
            xtype:‘panel‘,
            layout:"fit",
            closable: false,
            autoScroll: true,
            listeners: {
                resize: function (panel, width, height, oldWidth, oldHeight, eOpts) {
                    var temp=document.getElementById(‘back‘);
                    resizeImage(temp);

                }
            }
}

function resizeImageWidth(obj)
{
    var width = Ext.getCmp(‘northView‘).getWidth();
    obj.width=width;
    obj.height=60;
}




...
{
                id:‘northView‘,
                xtype:‘panel‘,
                region: ‘north‘,
                height:60,
                layout:"fit",
                html:‘<div style="position: relative"><div style="position: absolute"><img src="../../images/aas.png" height="60"/></div><img id="title" src="../../images/title.png"    onload="resizeImageWidth(this)"/></div>‘,
            
                listeners: {
                    resize: function (panel, width, height, oldWidth, oldHeight, eOpts) {
                        var temp=document.getElementById(‘title‘);
                         resizeImageWidth(temp);

                    }
                }
            }