---
title: BlockRange
framework: BlockStorageDeviceDriverKit
role: symbol
role_heading: Structure
platforms: [driverkit 21.0+]
path: blockstoragedevicedriverkit/blockrange
---

# BlockRange

A structure that represents a range of blocks.

## Declaration

```occ
struct BlockRange;
```

## Discussion

Discussion The pure virtual function _DoAsyncUnmap, which your dext must implement, takes this type as a parameter that indicates the blocks to unmap.

## Topics

### Accessing Block Range Properties

- [startBlock](blockstoragedevicedriverkit/blockrange/startblock.md)
- [numOfBlocks](blockstoragedevicedriverkit/blockrange/numofblocks.md)

## See Also

### Accessing the Device

- [DoAsyncUnmap](blockstoragedevicedriverkit/iouserblockstoragedevice/doasyncunmap.md)
- [DoAsyncSynchronize](blockstoragedevicedriverkit/iouserblockstoragedevice/doasyncsynchronize.md)
- [DoAsyncEjectMedia](blockstoragedevicedriverkit/iouserblockstoragedevice/doasyncejectmedia.md)
- [Complete](blockstoragedevicedriverkit/iouserblockstoragedevice/complete.md)
- [DoAsyncReadWrite](blockstoragedevicedriverkit/iouserblockstoragedevice/doasyncreadwrite.md)
- [IOUserStorageOptions](blockstoragedevicedriverkit/iouserstorageoptions.md)
- [CompleteIO](blockstoragedevicedriverkit/iouserblockstoragedevice/completeio.md)