怎么把base64字符串转成图片保存到本地

import fs from '@ohos.file.fs'; 
import buffer from '@ohos.buffer'; 
 
export function base64To(data: string, filePath: string) { 
  const reg = new RegExp("data:image/\\w+;base64,"); 
  const base64 = data.replace(reg, ""); 
  const dataBuffer = buffer.from(base64, 'base64'); 
  const file = fs.openSync(filePath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); 
  fs.writeSync(file.fd, dataBuffer.buffer); 
}