readyState
只读特性在
IDBRequest
interface returns the state of the request.
Every request starts in the
pending
state. The state changes to
done
when the request completes successfully or when an error occurs.
var currentReadyState = request.readyState;
IDBRequestReadyState
of the request, which takes one of the following two values:
| 值 | 含义 |
|---|---|
pending
|
The request is pending. |
done
|
The request is done.
|
The following example requests a given record title,
onsuccess
gets the associated record from the
IDBObjectStore
(made available as
objectStoreTitleRequest.result
), updates one property of the record, and then puts the updated record back into the object store in another request. The
readyState
of the 2nd request is logged to the developer console. For a full working example, see our
待办通知
app (
实时查看范例
)。
var title = "Walk dog";
// Open up a transaction as usual
var objectStore = db.transaction(['toDoList'], "readwrite").objectStore('toDoList');
// Get the to-do list object that has this title as it's title
var objectStoreTitleRequest = objectStore.get(title);
objectStoreTitleRequest.onsuccess = function() {
// Grab the data object returned as the result
var data = objectStoreTitleRequest.result;
// Update the notified value in the object to "yes"
data.notified = "yes";
// Create another request that inserts the item
// back into the database
var updateTitleRequest = objectStore.put(data);
// Log the source of this request
console.log("The readyState of this request is " + updateTitlerequest.readyState);
// When this new request succeeds, run the displayData()
// function again to update the display
updateTitleRequest.onsuccess = function() {
displayData();
};
};
| 规范 | 状态 | 注释 |
|---|---|---|
|
索引数据库 API 2.0
The definition of 'readyState' in that specification. |
推荐 | |
|
索引数据库 API 草案
The definition of 'readyState' in that specification. |
推荐 |
| 桌面 | 移动 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
readyState
|
Chrome
24
|
Edge 12 |
Firefox
16
|
IE 部分支持 10 | Opera 15 | Safari 7 | WebView Android Yes | Chrome Android Yes | Firefox Android 22 | Opera Android 14 | Safari iOS 8 | Samsung Internet Android Yes |
完整支持
部分支持
要求使用供应商前缀或不同名称。
IDBDatabase
IDBTransaction
IDBKeyRange
IDBObjectStore
IDBCursor
IDBRequest
IDBCursor
IDBCursorSync
IDBCursorWithValue
IDBDatabase
IDBDatabaseException
IDBDatabaseSync
IDBEnvironment
IDBEnvironmentSync
IDBFactory
IDBFactorySync
IDBIndex
IDBIndexSync
IDBKeyRange
IDBObjectStore
IDBObjectStoreSync
IDBOpenDBRequest
IDBTransaction
IDBTransactionSync
IDBVersionChangeEvent
IDBVersionChangeRequest