CodeMirror.MergeView(target, {
value: newValue,//上次内容
origLeft: null,
orig: oldValue,//本次内容
lineNumbers: true,//显示行号
mode: "text/html",
highlightDifferences: true,
connect: 'align',
revertButtons:false,
readOnly: true,//只读 不可修改
});