Class: QIODevice, QFileDevice, QFile, QTemporaryFile,……

QFile的用法：

QFile myFile = QFile("filename")
myFile.open(OpenMode mode)

这里OpenMode是一个枚举类型，只能是一下几种类型：

image.png

Certain flags, such as Unbuffered and Truncate, are meaningless when used with some subclasses. Some of these restrictions are implied by the type of device that is represented by a subclass. In other cases, the restriction may be due to the implementation, or may be imposed by the underlying platform; for example, QTcpSocket does not support Unbuffered mode, and limitations in the native API prevent QFile from supporting Unbuffered on Windows.

The OpenMode type is a typedef for QFlags <OpenModeFlag>. It stores an OR combination of OpenModeFlag values.

---

可以通过用|来连接两个不同的值如：

myFile.open( QIODevice.ReadOnly | QIODevice.Text )

类似于不同位上的开关同时打开

OpenMode类型是抽象模板QFlags的一种定义

open函数若打开文件成功会返回True否则返回False
但如果打开开关Write， 那么当文件不存在是会新建一个空白文件

QFile的其他用法