Ext的Anchor布局

Anchor布局的例子：

    //Anchor Layout要点:"1.容器内的组件要么指定宽度，要么在anchor中同时指定高/宽，2.anchor值通常只能为负值(指非百分比值)，正值没有意义，3.anchor必须为字符串值"     Ext.onReady(function() {        var panel1 = new Ext.Panel({             title: "panel1",             height: 100,             anchor: '-50',             html: "高度等于100，宽度=容器宽度-50"         });        var panel2 = new Ext.Panel({             title: "panel2",             height: 100,             anchor: '50%',             html: "高度等于100,宽度=容器宽度的50%"         });        var panel3 = new Ext.Panel({             title: "panel3",             anchor: '-10, -250',             html: "宽度=容器宽度-10,高度=容器高度-250"         });        var win = new Ext.Window({             title: "Anchor Layout",             height: 400,             width: 400,             plain: true,                                 layout: 'anchor',             items: [panel1, panel2,panel3]                     });         win.show();     });

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