1、向QTextEdit中当前光标位置添加一行字符串message
ui.messageTextEdit->textCursor().insertText(message+" ");
2、向QTextEdit中末尾追加一行字符串message
QString content = ui.contentTextEdit->append(message+" ");
3、读取QTextEdit的值
QString content = ui.contentTextEdit->toPlainText();
4、光标移到末尾
ui.textBrowser_2->moveCursor(QTextCursor::End);