javascript ArrayBuffer，它是做什么用的？

Question

也许是晚了，或者是缘故，但我刚刚阅读了 ArrayBuffer 的文档。也想不出它有什么用处。

谁能教教我？

有没有任何人能想到的不涉及图像的用途？

Answer 1

基本上ArrayBuffer是用来保存二进制数据的。例如，它可以是图像的二进制数据。

在其他语言中，缓冲区被证明非常有用。是的，当然它比其他数据类型更容易理解/使用。

ArrayBuffer 可用于获取 jpg 图像的数据(RGB 字节)并通过添加 alpha 字节(即 RGBA)从中生成 png。

Mozilla 站点给出了 ArrayBuffer 的小用途 here

Working with complex data structures

By combining a single buffer with multiple views of different types, starting at different offsets into the buffer, you can interact with data objects containing multiple data types. This lets you, for example, interact with complex data structures from WebGL, data files, or C structures you need to use while using js-ctypes.

Consider this C structure:

struct someStruct {  
  unsigned long id;  
  char username[16];  
  float amountDue;  
};  

You can access a buffer containing data in this format like this:

var buffer = new ArrayBuffer(24);  

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

var idView = new Uint32Array(buffer, 0, 1);  
var usernameView = new Uint8Array(buffer, 4, 16);  
var amountDueView = new Float32Array(buffer, 20, 1);  

Then you can access, for example, the amount due with amountDueView[0].

Note: The data structure alignment in a C structure is platform-dependent. Take precautions and considerations for these padding differences.