SOURCE

// 初始顶部功能按钮
toolsApp.initAction([{
    title: "生成二维码",
    icon: 'icon-play',
    click: () => {
        if ($('#qrtext').val().length > 353) {
            alert("有点太长了");
        } else {
            $('#qrcodeCanvas').html("");
            qrCode('qrcodeCanvas', $('#qrtext').val(), 260);
        }
    },
}, {
    title: "清空结果",
    icon: 'icon-trash',
    click: () => {
       $('#qrtext').val('');
    }
}]);

// 初始右边功能按钮
toolsApp.initTabs([]);


qrCode('qrcodeCanvas', "http://jsrun.net", 260);

<div class="ct">
	<input id="qrtext" type="input" value="" placeholder="请输入文本" />
 
  <div class="des">暂不支持中文</div>
    <div id="qrcodeCanvas">
    </div>
</div>

input {
    width: calc(100% - 55px);
    margin: 5px;
    height: 25px;
    padding: 10px;
    border-radius: 6px;
    outline: none;
    border: 1px solid #ccc;
}

.des {
    font-size: 12px;
    margin: auto;
    width: 100px;
    margin-top: 15px;
    color: #777;
}

button {
    height: 47px;
    margin-left: -9px;
    border-radius: 0px 25px 25px 0px;
    outline: none;
    width: 80px;
    border: 1px solid #217dcc;
    background: #3ca5ff;
    color: #FFF;
    font-size: 14px;
}

.ct {
    margin: auto;
    width: 401px; 
}

#qrcodeCanvas {
    margin: auto;
    width: 256px;
    margin-top: 100px;
}