2021-02-20 Qt: Get part of QString

I want to get QString from another QString with the necessary indexes.

Using left(), mid() and right() can do that

    QString myString("abcdefghijklmnopqrstuvwxyz");
    MainWindow::ui->textEdit_Log->append(myString);
    QString subString = myString.mid(5,2); // subString contains "fg"
    MainWindow::ui->textEdit_Log->append(subString);
    subString.append("!@#"); // subString contains "fg!@#"
    MainWindow::ui->textEdit_Log->append(subString);"

Result:

Example:

    // 宣告 1 秒的Timer
    var_timer_1s = startTimer(1000);
    currentTimeLabel = new QLabel; // 顯示時間的Label元件宣告
    ui->statusbar->addWidget(currentTimeLabel); // 在狀態欄中加入顯示時間的Label元件
    ...
    ...
    ...
    // 每秒固定的 Tasks
    // Update Date & Time
    var_current_time = QDateTime::currentDateTimeUtc(); // 獲得目前UTC時間
    var_timestr = var_current_time.toString( "yyyy-MM-ddThh:mm:ssZ"); // 設定顯示時間的格式
    currentTimeLabel->setText(var_timestr); // 更新狀態欄中現在時間
    ...
    ...
    // Get time from the date-time-string
    MainWindow::ui->textEdit_Log->append(var_timestr.mid(11,8)+": " + str);
    ...
    

QString left(int n) const

QString leftJustified(int width, QChar fill = QLatin1Char(' '), bool truncate = false) const

QStringRef leftRef(int n) const

QString mid(int position, int n = -1) const

QStringRef midRef(int position, int n = -1) const

QString right(int n) const

QString rightJustified(int width, QChar fill = QLatin1Char(' '), bool truncate = false) const

QStringRef rightRef(int n) const

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