vue17 $watch 监听数据变化
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>智能社——http://www.zhinengshe.com</title> <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0"> <meta name="apple-mobile-web-app-capable" content="yes"> <meta name="apple-mobile-web-app-status-bar-style" content="black"> <style> </style> <script src="vue.js"></script> <script> window.onload=function(){ var vm=new Vue({ el:'#box', data:{ a:111, b:2 } }); vm.$watch('a',function(){//监听器,a是监听哪个属性变化, alert('发生变化了'); this.b=this.a+100; }); document.onclick=function(){ vm.a=1; }; }; </script> </head> <body> <div id="box"> {{a}} <br> {{b}} </div> </body> </html>
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>智能社——http://www.zhinengshe.com</title> <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0"> <meta name="apple-mobile-web-app-capable" content="yes"> <meta name="apple-mobile-web-app-status-bar-style" content="black"> <style> </style> <script src="vue.js"></script> <script> window.onload=function(){ var vm=new Vue({ el:'#box', data:{ aajson:{name:'strive',age:16}, b:2 } }); vm.$watch('aajson',function(){//不能监听json alert('发生变化了'); }); document.onclick=function(){ vm.aajson.name='aaa'; }; }; </script> </head> <body> <div id="box"> {{aajson | json}} <!-- 后面的json是解析成json字符串 --> <br> {{b}} </div> </body> </html>
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>智能社——http://www.zhinengshe.com</title> <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0"> <meta name="apple-mobile-web-app-capable" content="yes"> <meta name="apple-mobile-web-app-status-bar-style" content="black"> <style> </style> <script src="vue.js"></script> <script> window.onload=function(){ var vm=new Vue({ el:'#box', data:{ ajson:{name:'strive',age:16}, b:2 } }); vm.$watch('ajson',function(){ alert('发生变化了'); },{deep:true}); document.onclick=function(){ vm.ajson.name='aaa'; }; }; </script> </head> <body> <div id="box"> {{ajson | json}} <br> {{b}} </div> </body> </html>