toFileSize method
将字节转为容量单位
Implementation
String? toFileSize({int decimals = 0}) {
if (this == null) {
return null;
}
if (this == 0) {
return '0 B';
}
const suffixes = ["B", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"];
var i = (log(this!) / log(1024)).floor();
return '${(this! / pow(1024, i)).toStringAsFixed(decimals)} ${suffixes[i]}';
}