百度智能小程序异步移除指定key

2020-09-05 14:15 更新

swan.removeStorage

解释：从本地缓存中异步移除指定 key。

方法参数

Object object

object参数说明

属性名	类型	必填	说明
key	String	是	本地缓存中的指定的 key
success	Function	否	接口调用成功的回调函数
fail	Function	否	接口调用失败的回调函数
complete	Function	否	接口调用结束的回调函数（调用成功、失败都会执行）

示例

图片示例

代码示例 1: 基础用法

在开发者工具中打开

<view class="wrap">
    <view class="card-area">
        <view class="list-area border-bottom">
            <label class="list-item-key-4">key</label>
            <input class="list-item-value" bindfocus="keyFocus" bindinput="keyInput" type="text" value="{{key}}" placeholder="请输入key" />
        </view>
        <view class="list-area border-bottom">
            <label class="list-item-key-4">value</label>
            <input class="list-item-value" bindfocus="valueFocus" bindinput="valueInput" type="text" value="{{value}}" placeholder="请输入value" />
        </view>
        <view>
            <button bindtap="setStorage" type="primary" hover-stop-propagation="true">存储数据</button>
            <button bindtap="getStorage" type="primary" hover-stop-propagation="true" disabled="{{disabled}}">读取数据</button>
            <button bindtap="getStorageInfo" type="primary" disabled="{{disabled}}">获取存储数据信息</button>
            <button bindtap="removeStorage" type="primary" hover-stop-propagation="true" disabled="{{disabled}}">移除第一个key对应的value值</button>
        </view>
    </view>
</view>

Page({
    data: {
        key: '示例Key',
        value: '示例Value',
        disabled: true
    },
    keyInput(e) {
        this.setData('key', e.detail.value);
    },
    valueInput(e) {
        this.setData('value', e.detail.value);
    },
    valueFocus() {
        this.setData('value', '');
    },
    keyFocus() {
        this.setData('key', '');
    },
    setStorage() {
        let key = this.hasKey();
        if (!key) {
            return;
        }

        swan.setStorage({
            key,
            data: this.getData('value'),
            success: res => {
                this.toast('存储成功', 'none');
                this.setData('disabled', false);
            },
            fail: err => {
                this.toast('存储数据失败');
            }
        });
    },
    getStorage() {
        let key = this.hasKey();
        if (!key) {
            return;
        }

        swan.getStorage({
            key,
            success: res => {
                const data = res.data;
                if (data) {
                    swan.showModal({
                        title: '数据信息',
                        content: `${key}: ${data}`,
                        showCancel: false
                    });
                }
                else {
                    this.toast('找不到key对应的值');
                }
            },
            fail: err => {
                this.toast('读取数据失败');
            }
        });
    },
    getStorageInfo() {
        swan.getStorageInfo({
            success: res => {
                swan.showModal({
                    title: '',
                    content: JSON.stringify(res)
                });
                this.setData({
                    keysList: res.keys
                });
                console.log('getStorageInfo success', res);
            },
            fail: err => {
                console.log('getStorageInfo fail', err);
            }
        });
    },
    removeStorage() {
        swan.getStorageInfo({
            success: res => {
                swan.removeStorage({
                    key: res.keys[0],
                    success: res => {
                        this.toast('removeStorage success', 'none');

                    },
                    fail: err => {
                        swan.showToast({
                            title: '没有key值可移除',
                            icon: 'none'
                        });
                        console.log('removeStorage fail', err);
                    }
                });
                console.log('getStorageInfo success', res);
            },
            fail: err => {
                console.log('getStorageInfo fail', err);
            }
        });
    },
    hasKey() {
        let key = this.getData('key');
        if (key) {
            return key;
        }

        this.toast('key不能为空');
    },
    toast(title, icon = 'none') {
        swan.showToast({title, icon});
    }
});

参考示例

参考示例 1：搜索历史

在开发者工具中打开

Page({
    data: {
        value: '',
        queryArr: []
    },
    valueInput(e) {
        this.setData('value', e.detail.value);
    },
    storageQuery() {
        let value = this.getData('value');
        let queryArr = this.getData('queryArr');
        if (value) {
            // 若输入的存储数据与之前相同，则去重
            const index = queryArr.findIndex(item => item === value);
            if (index > -1) {
                queryArr.splice(index, 1);
            }
            // 添加存储数组中的值
            queryArr.unshift(value);
            this.setData({queryArr});
        }
        const storeArr = queryArr.slice(0, 20);
        swan.setStorageSync('queryData', storeArr);
    },
    clearQuery() {
        swan.removeStorageSync('queryData');
        this.setData('queryArr', []);
        console.log('搜索历史清空成功');
    }
});