HTML5如何判断IndexedDB游标何时结束 [英] HTML5 How to tell when IndexedDB cursor is at end

问题描述

我通过indexedDB数据存储迭代，将数据添加到JavaScript数组。如何知道光标何时结束，所以我可以对数组进行排序并对其执行操作？

I am iterating thru an indexedDB data store, adding data to a JavaScript array. How can I tell when the cursor is at the end, so I can sort the array and act on it?

当从光标检索到一行时，调用onsuccess - 当整个光标被导航时，是否有另一个回调？

onsuccess is called when a row has been retrieved from the cursor - is there another callback when the entire cursor has been navigated?

推荐答案

结果（ event.target .result ）是一个游标对象或null。

The result (event.target.result) of a successful cursor request is either a cursor object or null.

如果设置了 event.target.result ，则它是游标，您可以访问 event.target.result.value 。然后，您可以调用 event.target.result.continue（）转到下一个对象（如果有）。

If event.target.result is set, it's the cursor, and you can access event.target.result.value. You can then call event.target.result.continue() to go on to the next object, if any.

如果未设置 event.target.result ，则没有更多对象。

If event.target.result is not set, then there are no more objects.

为了说明，我的一个项目的一些代码：

For illustration, some code from a project of mine:

  var collectObjects = function (request, cb) {
    var objects = []
    request.onsuccess = function (event) {
      if (!event.target.result) return cb(null, objects)
      cursor = event.target.result
      objects.push(cursor.value)
      cursor.continue()
    }
    request.onerror = function (event) {
      cb(event.target.error)
    }

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