Vue.js 错误: "TypeError: Cannot read property 'form' of undefined" 的解决方法

{"title": "onLoad() {\n\t\tthis.getActivity()\n\t},\n\t\t\tfilters: { //设置最大可选\n\t\t\tselectName(compositionId) {\n\t\t\t\tlet num = parseInt(compositionId);\n\t\t\t\tif (this.form.onceVoteAmount > 0 && this.form.onceVoteAmount == this.checkedValues.length) {\n\t\t\t\t\tfor (var t in this.checkedValues) {\n\t\t\t\t\t\tif (t == num) {\n\t\t\t\t\t\t\treturn false\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\t\t\t\t\treturn true\n\t\t\t\t} else {}\n\t\t\t\treturn false\n\t\t\t},\n\t\t\tmethods: {\n\t\t\t\tgetActivity() {\n\t\t\t\t\tconst url_params = Object.fromEntries(window.location.search.slice(1).split('&').map(v => v.split('=')));\n\t\t\t\t\tuni.request({\n\t\t\t\t\t\turl: config.baseUrl + /activity/ + url_params.activityId,\n\t\t\t\t\t\tmethod: 'GET',\n\t\t\t\t\t\tsuccess: res => {\n\t\t\t\t\t\t\tif (res.data.code === 200) {\n\t\t\t\t\t\t\t\tthis.form = res.data.data\n\t\t\t\t\t\t\t}\n\t\t\t\t\t\t}\n\t\t\t\t\t})\n\t\t\t\t},\n\t\t\t},\n\t\t[Vue warn]: Error in render: "TypeError: Cannot read property 'form' of undefined"\n\t\t代码有什么问题内容：代码的问题在于在onLoad()方法中调用了this.getActivity()，但是onLoad()方法没有定义在methods中，导致无法调用this.getActivity()方法。将onLoad()方法定义在methods中即可解决问题。修改后的代码如下：\n\n\t\tonLoad() {\n\t\tthis.getActivity()\n\t},\n\t\tmethods: {\n\t\t\tgetActivity() {\n\t\t\t\tconst url_params = Object.fromEntries(window.location.search.slice(1).split('&').map(v => v.split('=')));\n\t\t\t\tuni.request({\n\t\t\t\t\turl: config.baseUrl + /activity/ + url_params.activityId,\n\t\t\t\t\tmethod: 'GET',\n\t\t\t\t\tsuccess: res => {\n\t\t\t\t\t\tif (res.data.code === 200) {\n\t\t\t\t\t\t\tthis.form = res.data.data\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\t\t\t\t})\n\t\t\t},\n\t\t\tfilters: { //设置最大可选\n\t\t\t\tselectName(compositionId) {\n\t\t\t\t\tlet num = parseInt(compositionId);\n\t\t\t\t\tif (this.form.onceVoteAmount > 0 && this.form.onceVoteAmount == this.checkedValues.length) {\n\t\t\t\t\t\tfor (var t in this.checkedValues) {\n\t\t\t\t\t\t\tif (t == num) {\n\t\t\t\t\t\t\t\treturn false\n\t\t\t\t\t\t\t}\n\t\t\t\t\t\t}\n\t\t\t\t\t\treturn true\n\t\t\t\t\t} else {}\n\t\t\t\t\treturn false\n\t\t\t\t},\n\t\t\t},\n\t\t}