An introduction to several methods of passing and retrieving values ​​in WeChat development

This article mainly introduces the relevant information summarized by several methods of transferring and obtaining values ​​​​in WeChat mini programs. Here are detailed explanations of these methods, and sample codes are attached. Friends in need can refer to it

WeChat applet passing value

The common values ​​​​in the applet are as follows. If you write down a complete project, the probability of using it is almost 100%.

• List index subscript value

• Page value passing

• form form value

1. List index subscript value

The implementation method is: data-index="{{index}}" digging and e .currentTarget.dataset.index to fill in the pit

1.1 Generate value

<image src="../../../images/icon_delete.png" /><text>删除</text>

Add data-index="{{index}}" custom attributes and bindings to the delete icon and text Click event bindtap="delete"

<image src="../../../images/icon_delete.png" /><text>删除</text>

implement the delete method and get the index subscript value.

delete: function (e) {
  var index = parseInt(e.currentTarget.dataset.index);
  console.log("index" + index);
}

What happens if e.target is used instead of e.currentTarget?

will cause the index value to be output only if the is clicked, and the click element or will output NaN.

What is the use of target? It is used to distinguish sub-elements from external elements when they need to be processed separately. For example, when changing the user's avatar, click on the avatar itself to preview the large image, and Click the entire line where the avatar is to switch the avatar.

1.2 Get the value

Try to find the deletion address of the corresponding element from the index data

// 找到当前地址AVObject对象
var address = that.data.addressObjects[index];
// 给出确认提示框
wx.showModal({
  title: '确认',
  content: '要删除这个地址吗？',
  success: function(res) {
    if (res.confirm) {
      // 真正删除对象
      address.destroy().then(function (success) {
        // 删除成功提示
        wx.showToast({
          title: '删除成功',
          icon: 'success',
          duration: 2000
        });
        // 重新加载数据
        that.loadData();
      }, function (error) {

      });
    }
  }
})

2. Page value passing

Pass the address id from the shipping address list page to the editing page to read the original address for modification.

The address/list page implements the following code

<view class="container" data-index="{{index}}" bindtap="edit"><image src="../../../images/icon_edit.png" /><text>编辑</text></view>

edit: function (e) {
  var that = this;
  // 取得下标
  var index = parseInt(e.currentTarget.dataset.index);
  // 取出id值
  var objectId = this.data.addressObjects[index].get(&#39;objectId&#39;);
  wx.navigateTo({
    url: &#39;../add/add?objectId=&#39;+objectId
  });
},

The address/add page implements the onLoad(options) method, from the url path Get the objectId

onLoad: function (options) {
  var objectId = options.objectId
}

and then access the network and render the page.

3. Form form value

3.1 Method 1, through

<form bindsubmit="formSubmit">
  <input name="detail" placeholder="详情地址" />
  <input name="realname" placeholder="收件人姓名" />
  <input name="mobile" placeholder="手机号码" type="number"/>
  <button formType="submit" type="primary">Submit</button>
</form>

formSubmit: function(e) {
  // detail
  var detail = e.detail.value.detail;
  // realname
  var realname = e.detail.value.realname;
  // mobile
  var mobile = e.detail.value.mobile;
}

// 实现相应多个**Confirm方式
detailConfirm: function(e) {
  var detail = e.detail.value;
}
realnameConfirm: function(e) {
  var realname = e.detail.value;
}
mobileConfirm: function(e) {
  var mobile = e.detail.value;
}