htm5本地存储方案——indexdb的封装
时间：2021-07-01 10:21:17
帮助过：74人阅读
封装IndexdDB*/
var localDatabase =
{
};
localDatabase.dbName = "yiliDB"
;
localDatabase.indexedDB = window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB ||
window.msIndexedDB;
localDatabase.db =
null;
localDatabase.IDBKeyRange = window.IDBKeyRange ||
window.webkitIDBKeyRange;
localDatabase.IDBCursor = window.IDBCursor ||
window.webkitIDBCursor;
localDatabase.IDBTransaction = window.IDBTransaction ||
window.webkitIDBTransaction;
localDatabase.indexedDB.onerror =
function(e) {
console.log("Database error: " +
e.target.errorCode);
};
//删除数据库
localDatabase.deleteIndexdDB =
function() {
var deleteDbRequest =
localDatabase.indexedDB.deleteDatabase(localDatabase.dbName);
deleteDbRequest.onsuccess =
function(event) {
console.log(‘Database deleted‘
);
localDatabase.db =
null;
};
deleteDbRequest.onerror =
function(e) {
console.log("Database error: " +
e.target.errorCode);
};
};
//打开数据库
localDatabase.openIndexdDB =
function(callback) {
console.log("init IndexdDB"
);
try {
var openRequest =
localDatabase.indexedDB.open(localDatabase.dbName);
openRequest.onerror =
function(e) {
callback("Database error: " +
e.target.errorCode);
};
openRequest.onsuccess =
function(event) {
localDatabase.db =
openRequest.result;
console.log("Open IndexdDB success."
);
callback("success"
);
localDatabase.db.onversionchange =
function() {
console.log("DB close"
);
localDatabase.db.close();
};
};
openRequest.onupgradeneeded =
function(evt) {
console.log(‘Creating object stores‘
);
var MessageStore = evt.currentTarget.result.createObjectStore("message"
);
MessageStore.createIndex("userid", "userid"
, {
unique: false
});
};
} catch(e1) {
console.log(e1);
}
};
再来个测试的例子
//添加消息
localDatabase.addMessageToIndexDB = function(obj, userid) {
try {
console.log(localDatabase.db);
if(localDatabase != null && localDatabase.db != null) {
var transaction = localDatabase.db.transaction("message", "readwrite");
var store = transaction.objectStore("message");
var request = store.get(userid);
request.onsuccess = function(e) {
var result = e.target.result;
var exist = 0;
if(typeof result != ‘undefined‘) {
for(var i = 0; i < result.length; i++) {
if(result[i].userid == obj.userid) {
result[i] = obj;
exist++;
break;
}
}
if(!exist) {
result.push(obj);
}
store.put(result, userid);
} else {
store.add([obj], userid);
}
};
}
} catch(e) {
console.log(e)
}
};
//获取消息
localDatabase.getMessage = function(userid, callback) {
try {
if(localDatabase != null && localDatabase.db != null) {
var store = localDatabase.db.transaction("message").objectStore("message");
// var index = store.index("userid");
// var request = index.openCursor(IDBKeyRange.only(userid));
request = store.get(userid);
request.onsuccess = function(res) {
var result = res.target.result;
if(typeof result != ‘undefined‘) {
callback(result);
} else {
callback(null);
}
};
}
} catch(e) {
console.log(e);
}
};
htm5本地存储方案——indexdb的封装
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