Qt实战开发-数字软键盘

开发的思路

布局键盘界面每一个button对应一个槽函数

把输入的字符返回到点击处的文本编辑框

开发过程

首先定义功能button，在头文件中定义

QString getText(); QPushButton *num6Button; QPushButton *backspaceButton; QPushButton *num4Button; QPushButton *okButton; QPushButton *leftButton; QPushButton *num1Button; QPushButton *cancelButton; QPushButton *rightButton; QPushButton *num9Button; QPushButton *num8Button; QPushButton *num2Button; QPushButton *num7Button; QPushButton *dotButton; QPushButton *num3Button; QPushButton *num0Button; QPushButton *num5Button; QPushButton *signButton; QLineEdit *lineEdit;

接着定义相关联的槽函数

void on_num1Button_clicked(); void on_num2Button_clicked(); void on_num3Button_clicked(); void on_num4Button_clicked(); void on_num5Button_clicked(); void on_num6Button_clicked(); void on_num7Button_clicked(); void on_num8Button_clicked(); void on_num9Button_clicked(); void on_dotButton_clicked(); void on_num0Button_clicked(); void on_signButton_clicked(); void on_leftButton_clicked(); void on_rightButton_clicked(); void on_backspaceButton_clicked(); void on_cancelButton_clicked(); void on_okButton_clicked();

下面定义界面布局显示的功能模块

okButton = new QPushButton(this); okButton->setText(" OK"); okButton->setGeometry(QRect(190, 250, 110, 50)); QFont font1; font1.setPointSize(14); okButton->setFont(font1); backspaceButton = new QPushButton(this); backspaceButton->setText(" backspace"); backspaceButton->setGeometry(QRect(190, 130, 110, 50)); backspaceButton->setFont(font1); num6Button = new QPushButton(this); num6Button->setText("6"); num6Button->setGeometry(QRect(130, 130, 50, 50)); QFont font; font.setPointSize(22); num6Button->setFont(font); num4Button = new QPushButton(this); num4Button->setText(" 4"); num4Button->setGeometry(QRect(10, 130, 50, 50)); num4Button->setFont(font); leftButton = new QPushButton(this); leftButton->setText("<-"); leftButton->setGeometry(QRect(190, 190, 50, 50)); leftButton->setFont(font); num1Button = new QPushButton(this); num1Button->setText("1"); num1Button->setGeometry(QRect(10, 70, 50, 50)); num1Button->setFont(font); cancelButton = new QPushButton(this); cancelButton->setText("Esc"); cancelButton->setGeometry(QRect(190, 70, 110, 50)); cancelButton->setFont(font1); rightButton = new QPushButton(this); rightButton->setText("->"); rightButton->setGeometry(QRect(250, 190, 50, 50)); rightButton->setFont(font); num9Button = new QPushButton(this); num9Button->setText("9"); num9Button->setGeometry(QRect(130, 190, 50, 50)); num9Button->setFont(font); num8Button = new QPushButton(this); num8Button->setText("8"); num8Button->setGeometry(QRect(70, 190, 50, 50)); num8Button->setFont(font); num2Button = new QPushButton(this); num2Button->setText("2"); num2Button->setGeometry(QRect(70, 70, 50, 50)); num2Button->setFont(font); num7Button = new QPushButton(this); num7Button->setText("7"); num7Button->setGeometry(QRect(10, 190, 50, 50)); num7Button->setFont(font); dotButton = new QPushButton(this); dotButton->setText("."); dotButton->setGeometry(QRect(130, 250, 50, 50)); dotButton->setFont(font); num3Button = new QPushButton(this); num3Button->setText("3"); num3Button->setGeometry(QRect(130, 70, 50, 50)); num3Button->setFont(font); num0Button = new QPushButton(this); num0Button->setText("0"); num0Button->setGeometry(QRect(10, 250, 50, 50)); num0Button->setFont(font); num5Button = new QPushButton(this); num5Button->setText("5"); num5Button->setGeometry(QRect(70, 130, 50, 50)); num5Button->setFont(font); signButton = new QPushButton(this); signButton->setText("+/-"); signButton->setGeometry(QRect(70, 250, 50, 50)); QFont font2; font2.setPointSize(20); signButton->setFont(font2); lineEdit = new QLineEdit(this); lineEdit->setGeometry(QRect(10, 10, 290, 50)); QFont font3; font3.setPointSize(24); font3.setWeight(50); lineEdit->setFont(font3); lineEdit->setText(QString());

相应的槽函数功能

void NumKeyboard::changeEvent(QEvent *e) { QDialog::changeEvent(e); switch (e->type()) { case QEvent::LanguageChange: break; default: break; } } bool NumKeyboard::eventFilter(QObject *obj, QEvent *event) { if (event->type() == QEvent::KeyPress) { QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event); if (obj == lineEdit) { if(keyEvent->key() >= 0x20 && keyEvent->key()<= 0x0ff) return true; else return false; } else { return false; } } else { // standard event processing return QObject::eventFilter(obj, event); } } //***********************按键*****************************// void NumKeyboard::on_num1Button_clicked() //1 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '1'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); qDebug()<<"strContent"<<strContent; qDebug()<<"idx"<<idx; } void NumKeyboard::on_num2Button_clicked() //2 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '2'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_num3Button_clicked() //3 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '3'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_num4Button_clicked() //4 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '4'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_num5Button_clicked() //5 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '5'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_num6Button_clicked() //6 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '6'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_num7Button_clicked() //7 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '7'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_num8Button_clicked() //8 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '8'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_num9Button_clicked() //9 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '9'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_dotButton_clicked() //. { int idx = lineEdit->cursorPosition(); if(idx==0 || strContent.contains('.')) { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '.'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_num0Button_clicked() //0 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0" || (idx==0 &&strContent!="")) { lineEdit->setCursorPosition(idx); qDebug()<<"idx"<<idx; lineEdit->setFocus(); return; } strContent.insert(idx, '0'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_signButton_clicked() //+/- { int idx = lineEdit->cursorPosition(); if(strContent.left(1) == "-") { strContent.remove(0, 1); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx-1); lineEdit->setFocus(); } else { if(strContent=="0" || strContent=="") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); } else { strContent.insert(0, '-'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } } } void NumKeyboard::on_leftButton_clicked() //left { int idx = lineEdit->cursorPosition(); if(idx == 0) { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } lineEdit->setCursorPosition(idx-1); lineEdit->setFocus(); } void NumKeyboard::on_rightButton_clicked() //right { int idx = lineEdit->cursorPosition(); if(idx == strContent.length()) //返回此字符串的字符数 { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); } void NumKeyboard::on_backspaceButton_clicked() //backspace { int idx = lineEdit->cursorPosition(); if(idx == 0) { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.remove(idx-1,1); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx-1); lineEdit->setFocus(); } void NumKeyboard::on_cancelButton_clicked() //cancel { this->close(); valid = false; } void NumKeyboard::on_okButton_clicked() //ok { this->close(); valid = true; } void NumKeyboard::setText(QString str) //设置文本内容 { strContent = str; lineEdit->setText(strContent); lineEdit->setFocus(); } QString NumKeyboard::getText() //获取内容 { return strContent; }

上面的槽函数中只对大体的相似，只对不同处做出讲解 以点击“1”为例： 获取在软键盘中的文本框中光标的位置，赋值给idx，索引用

int idx = lineEdit->cursorPosition();

官方的解释如下 QString x = “Pineapple”; QString y = x.left(4); // y == “Pine” 同理下面的代码含义是：把当前光标位置左侧所有的数，存放在strContent中， if判断的作用是，当数值开头是0，便不能够输入。一个简单的检查的功能，例如无法输入”01“

insert的官方解释 QString str = “Meal”; str.insert(1, QString(“ontr”)); // str == “Montreal” 下面语句的作用是在当前的坐标处出插入1；把新的字符串返回给strContent （初始时idx=0，光标位置是0） strContent.insert(idx, ‘1’); 随后设置当前的光标的位置+1， lineEdit->setCursorPosition(idx+1); 显示光标 lineEdit->setFocus();

void NumKeyboard::on_num1Button_clicked() //1 { int idx = lineEdit->cursorPosition(); if(strContent.left(idx) == "0") { lineEdit->setCursorPosition(idx); lineEdit->setFocus(); return; } strContent.insert(idx, '1'); lineEdit->setText(strContent); lineEdit->setCursorPosition(idx+1); lineEdit->setFocus(); }

在设置正负的时候还会用到 strContent.remove(0, 1); 官方的解释是： QString s = “Montreal”; s.remove(1, 4); // s == “Meal” 上面的含义是，在0的位置删除1个字符。就是数字前面的+、-

在设置右移的槽函数中 idx == strContent.length()) //返回此字符串的字符数

最后通过getText() 函数获取文本的内容

QString NumKeyboard::getText() //获取内容 { return strContent; }

void SoftKeyLineEdit::mousePressEvent(QMouseEvent *e) { if(e->button() == Qt::LeftButton) { numkeyboard->setText(this->text()); numkeyboard->exec(); if(numkeyboard->valid) { this->setText(numkeyboard->getText()); } } }

我们通过鼠标点击的方式来触发软键盘 下面的函数的作用是：把当前的文本框中的内容传递给软件盘中的文本框 numkeyboard->setText(this->text()); 下面的exec()与show()显示的方式有所不同。 exec(): 显示一个模式对话框，并且锁住程序直到用户关闭该对话框为止。 show(): 显示一个非模式对话框。控制权即刻返回给调用函数。 numkeyboard->exec(); 如果点击“确认”按键后 valid返回值是true if(numkeyboard->valid)

随后把返回得到的字符串，传递到点击处的文本框中。 this->setText(numkeyboard->getText());

如何快速一个上面的软键盘到项目中 1.包含上面的cpp和.h文件 2.通过触发的方式触发下面语句 numkeyboard->setText(this->text()); numkeyboard->exec(); if(numkeyboard->valid) { this->setText(numkeyboard->getText()); } 3.触发方式可以是信号（例如clicked()） 另外看还可以是mousePressEvent(); 它的使用方式要重写 细节（QString 定义的strContent存储有引用计数，指向相同的存储空间，仅仅 是增加一个引用计数）

效果图

源代码下载 http://download.csdn.net/detail/osean_li/9773460