uni showLoading 还有注意关闭 闭包， .finally

    uni.showLoading({
        title:'正在提交...'
    });
    let data = JSON.parse(JSON.stringify($this.sendData));
    const r = instance.post({
        url : url,
        data: data
    })
    .then(res => {
        console.log(res)
        uni.showToast({ title: '提交成功', icon: "none", position:'bottom'});
    })
    .catch(err => {
        uni.showToast({ title: '提交失败', icon: "none", position:'bottom'});
    })
    .finally(() => {
        uni.hideLoading();
        console.log('finally')
    });