Version: 2023.1
public static Unity.IO.LowLevel.Unsafe.ReadHandle Read (string filename, ReadCommand* readCmds, uint readCmdCount, string assetName, ulong typeID, Unity.IO.LowLevel.Unsafe.AssetLoadingSubsystem subsystem);

参数

filename 要读取的文件名。
readCmds 指向 ReadCommand 结构(用于指定偏移、大小和目标缓冲区)数组的指针。
readCmdCount readCmds 指向的读取命令数。
assetName (Optional) The name of the object being read, for metrics purposes.
typeID (Optional) The TypeID of the object being read, for metrics purposes.
subsystem (Optional) The Subsystem tag for the read operation, for metrics purposes.

返回

ReadHandle 用于监控读取命令的进度和状态。

描述

发出一个异步文件读取操作。返回 ReadHandle。

You can set the assetName, typeId, and subsystem parameters to collect asset-specific metrics for this read operation. When you enable metrics collection with AsyncReadManagerMetrics.StartCollectingMetrics, Unity includes this information as part of the AsyncReadManagerMetrics, allowing you to analyze how different types of assets affect performance.

The AsyncReadManager copies the data referenced by Read; you can dispose or free the data immediately after calling Read.

using System.IO;
using Unity.Collections;
using Unity.IO.LowLevel.Unsafe;
using Unity.Collections.LowLevel.Unsafe;
using UnityEngine;

class AsyncReadSample : MonoBehaviour { private ReadHandle readHandle; NativeArray<ReadCommand> cmds; string assetName = "myfile"; ulong typeID = 114; // from ClassIDReference AssetLoadingSubsystem subsystem = AssetLoadingSubsystem.Scripts;

public unsafe void Start() { string filePath = Path.Combine(Application.streamingAssetsPath, "myfile.bin"); cmds = new NativeArray<ReadCommand>(1, Allocator.Persistent); ReadCommand cmd; cmd.Offset = 0; cmd.Size = 1024; cmd.Buffer = (byte*)UnsafeUtility.Malloc(cmd.Size, 16, Allocator.Persistent); cmds[0] = cmd; readHandle = AsyncReadManager.Read(filePath, (ReadCommand*)cmds.GetUnsafePtr(), 1, assetName, typeID, subsystem); }

public unsafe void Update() { if (readHandle.IsValid() &amp;&amp; readHandle.Status != ReadStatus.InProgress) { Debug.LogFormat("Read {0}", readHandle.Status == ReadStatus.Complete ? "Successful" : "Failed"); readHandle.Dispose(); UnsafeUtility.Free(cmds[0].Buffer, Allocator.Persistent); cmds.Dispose(); } } }

参数

fileHandle The FileHandle to be read from, opened by AsyncReadManager.OpenFileAsync.
readCmdArray A struct containing the read commands to queue.

返回

ReadHandle A ReadHandle object you can use to check the status and monitor the progress of the read operations.

描述

Queues a set of read operations for a file opened with OpenFileAsync.

This function makes a copy of the ReadCommandArray struct passed as a parameter internally, so you do not need to maintain the array. Note: WebGL builds do not support using AsyncReadManager to open files from a remote web server; for example, from the path Application.streamingAssetsPath which maps to a URL on a remote web server.

using System.IO;
using Unity.Collections;
using Unity.IO.LowLevel.Unsafe;
using Unity.Collections.LowLevel.Unsafe;
using UnityEngine;
using Unity.Jobs;

class AsyncReadSample : MonoBehaviour { static string TestFilename = Path.Combine(Application.streamingAssetsPath, "myfile.bin");

public unsafe void Start() { ReadCommand cmd; cmd.Offset = 0; cmd.Size = 1024; cmd.Buffer = (byte*)UnsafeUtility.Malloc(cmd.Size, 16, Allocator.Persistent);

FileHandle fileHandle = AsyncReadManager.OpenFileAsync(TestFilename);

ReadCommandArray readCmdArray; readCmdArray.ReadCommands = &amp;cmd; readCmdArray.CommandCount = 1;

ReadHandle readHandle = AsyncReadManager.Read(fileHandle, readCmdArray);

JobHandle closeJob = fileHandle.Close(readHandle.JobHandle);

closeJob.Complete();

// ... Use the data read into the buffer

readHandle.Dispose();

for (int i = 0; i < readCmdArray.CommandCount; i++) UnsafeUtility.Free(readCmdArray.ReadCommands[i].Buffer, Allocator.Persistent); } }