var reg=/\[Desktop\](?:(?!Visible=true)[\s\S])*Visible=true/g;
var str='[Desktop] \r\nTextId=Desktop\r\nTextFile=explorer\r\nTextContext=Desktopc\r\nPictu
re=\r\nSoftkeyPosition=9\r\nAccessLevel=7\r\nVisible=true\r\n[Desktop] \r\nTextId=Desktop\r\nTextFile=explorer\r\nTextContext=Desktopc\r\nPicture=\r\nSoftkeyPosition=9\r\nAccessLevel=1\r\nVisible=true\r\n[Desktop1] \r\nTextId=Desktop\r\nTextFile=explorer\r\nTextContext=Desktopc\r\nPicture=\r\nSoftkeyPosition=9\r\nAccessLevel=1\r\nVisible=true\r\n\r\n删除其中的\r\n从[Desktop] 到Visible=true的内容。';
str.replace(reg,"");