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• 摘要
• 句法
• 范例
• 规范
• 另请参阅
• 相关话题

This API is available on Firefox OS for privileged or certified applications 仅。

摘要

available() method is used to check whether the storage area is available; this is an asynchronous operation that returns a DOMRequest object that will receive a callback when the operation is complete.

The request's result may be:

'available'

Meaning that the storage area is available.

'unavailable'

Meaning that the storage area is not available. E.g. The SD card has need been inserted.

'shared'

Meaning the storage area is not available because the device is currently being used for USB storage.

句法

var instanceOfDOMRequest = instanceOfDeviceStorage.available();
					

返回

返回 DOMRequest object to report the success or error of the operation.

范例

var sdcard = navigator.getDeviceStorage("sdcard");
var request = sdcard.available();
request.onsuccess = function () {
  // The result is a string
  if (this.result == "available") {
    console.log("The SDCard on your device is available");
  } else if (this.result == "unavailable") {
    console.log("The SDcard on your device is not available");
  } else {
    console.log("The SDCard on your device is shared and thus not available");
  }
}
request.onerror = function () {
  console.warn("Unable to get the space used by the SDCard: " + this.error);
}
					

规范

Not part of any specification.

另请参阅

• DeviceStorage
• DOMRequest
• Device Storage API

元数据

• 最后修改： 2019 年 3 月 23 日

相关话题

1. Device Storage API
2. Archive
3. 事件
   1. change
4. Related pages for Device Storage API
   1. DeviceStorage
   2. DeviceStorageChangeEvent
   3. Navigator.getDeviceStorage()