qt QString::indexOf 字符串查找/截取

int QString::indexOf(QLatin1String str, int from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

Returns the index position of the first occurrence of the string str in this string, searching forward from index position from. Returns -1 if str is not found.

If cs is Qt::CaseSensitive (default), the search is case sensitive; otherwise the search is case insensitive.

Example:

  QString x = "sticky question";

  QString y = "sti";

  x.indexOf(y);               // returns 0

  x.indexOf(y, 1);            // returns 10

  x.indexOf(y, 10);           // returns 10

  x.indexOf(y, 11);           // returns -1

If from is -1, the search starts at the last character; if it is -2, at the next to last character and so on.