学习了上一篇博客关于QLineEdit的一些重要的成员函数和信号的用法之后，我们写一个小程序来熟练下这些函数.
这里是程序完成后的图片.
首先，我们现在ui设计师里拖拽出以下的布局:
注意箭头处还有个QLabel部件.
以下是”c.cpp”下的代码:
#include "c.h"c::c(QWidget *parent): QWidget(parent){ ui.setupUi(this); //设置标题为"QLineEdit" this->setWindowTitle("QQ"); //设置图标. this->setWindowIcon(QIcon("pixmap.jpg")); //设置为伙伴. ui.accountLabel->setBuddy(ui.accountLineEdit); ui.passwordLabel->setBuddy(ui.passwordLineEdit); //设置头像. ui.pixmapLabel->setPixmap(QPixmap("pixmap.jpg")); //让label完整的放下图片.根据比例缩减. ui.pixmapLabel->setScaledContents(true); //设置密码输入框的显示模式为:密码显示模式. ui.passwordLineEdit->setEchoMode(QLineEdit::Password); //设置激活两个输入框的清空按钮. ui.accountLineEdit->setClearButtonEnabled(true); ui.passwordLineEdit->setClearButtonEnabled(true); //设置两个输入框的最大长度 ui.accountLineEdit->setMaxLength(10); ui.passwordLineEdit->setMaxLength(10); //设置账号输入框允许拖拽. ui.accountLineEdit->setDragEnabled(true); //设置密码输入框不接受拖拽的文本. ui.passwordLineEdit->setAcceptDrops(false); //设置两个输入框的占位符. ui.accountLineEdit->setPlaceholderText(QString::fromLocal8Bit("必须为纯数字")); ui.passwordLineEdit->setPlaceholderText(QString::fromLocal8Bit("两位字母+纯数字")); //设置账号输入框的整数验证器，并且设定输入的范围. QIntValidator *account = new QIntValidator; account->setBottom(0); ui.accountLineEdit->setValidator(account); //设置密码输入框的验证器，用了正则表达式来规定:前面1-2个必须是字母，后面8-9个必须是0-9内的数字. QRegExp password("[A-Za-z]{2}[0-9]{8，9}"); ui.passwordLineEdit->setValidator(new QRegExpValidator(password, this)); //设置密码输入框中，按鼠标右键无菜单显示.和QQ一样.有心的小伙伴可以去试一下. ui.passwordLineEdit->setContextMenuPolicy(Qt::NoContextMenu); //但是对于Ctrl+V粘贴的快捷操作还没有屏蔽.有兴趣的可以去自己试试.这里不展开了. //连接信号与槽. connect(ui.showAccountButton, SIGNAL(clicked()), this, SLOT(showAccountNameSlot())); connect(ui.showPasswordButton, SIGNAL(clicked()), this, SLOT(showPasswordSlot())); connect(ui.pushButton, SIGNAL(clicked()), this, SLOT(showEntryDialogSlot())); connect(ui.passwordLineEdit, SIGNAL(returnPressed()), ui.pushButton, SIGNAL(clicked()));}c::~c(){}void c::showAccountNameSlot(){ QMessageBox::information(this, QString::fromLocal8Bit("账号:"), ui.accountLineEdit->text());}void c::showPasswordSlot(){ //注意text()返回的是本身的文本，而displayText()返回的是显示的文本. QMessageBox::information(this, QString::fromLocal8Bit("密码:"), ui.passwordLineEdit->text());}void c::showEntryDialogSlot(){ //这里只是为了演示QLineEdit的用法，就没有实现注册，登录等功能.所以这是简单的登陆下. if ((ui.accountLineEdit->text() == "123456") && (ui.passwordLineEdit->text() == "qw123456")) { QMessageBox::information(this, QString::fromLocal8Bit("登录"), QString::fromLocal8Bit("登录成功")); } else { QMessageBox::warning(this, QString::fromLocal8Bit("登录"), QString::fromLocal8Bit("登录失败")); }}12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879 以下是”c.h”内的代码:
#ifndef C_H#define C_H#include#include "ui_c.h"#include #include #include #include #include #include #include #include class c : public QWidget{ Q_OBJECTpublic: c(QWidget *parent = 0); ~c();private slots: void showAccountNameSlot(); void showPasswordSlot(); void showEntryDialogSlot();private: Ui::cClass ui;};#endif // C_H1234567891011121314151617181920212223242526272829303132
最后是”main.cpp”内的代码:
#include "c.h"#includeint main(int argc, char *argv[]){ QApplication a(argc, argv); c w; w.show(); return a.exec();}