我們接下來繼續把 GUIDemo 的功能完成，還有兩個按鈕 Clear 與 Copy 沒有實作功能。我們打算用 clearContact() 建置 Clear 的功能，另外用 copyContact() 建置 Copy 的功能，因此要在 GUIDemo.h 加入這兩個函數成員 (function member) 的宣告，修改過後的 GUIDemo.h 如下
#ifndef GUIDEMO_H
#define GUIDEMO_H
#include <QWidget>
#include "Encrypt.h"
class QLabel;
class QLineEdit;
class QPushButton;
class GUIDemo : public QWidget {
Q_OBJECT
public:
GUIDemo(QWidget *parent = 0);
QString s2q(const string &);
string q2s(const QString &);
public slots:
void newEncrypt();
void loadEncrypt();
void saveEncrypt();
void encodeContact();
void decodeContact();
void clearContact();
void copyContact();
void inputContact();
private:
QLabel *display;
QLineEdit *inputField;
QLineEdit *outputField;
QPushButton *newButton;
QPushButton *loadButton;
QPushButton *saveButton;
QPushButton *encodeButton;
QPushButton *decodeButton;
QPushButton *clearButton;
QPushButton *copyButton;
QString inputText;
QString outputText;
Encrypt *e;
};
#endif
/* 《程式語言教學誌》的範例程式
http://pydoing.blogspot.com/
檔名：GUIDemo.h
功能：示範 C++ 程式
作者：張凱慶
時間：西元 2012 年 10 月 */clearContact() 很簡單，我們把 inputText 、 outputText 、 inputField 與 outputField 都設定成空字串 (string) 就達到清空的目的，然後在 display 顯示提示訊息
void GUIDemo::clearContact() {
inputText = "";
outputText = "";
inputField->setText("");
outputField->setText("");
display->setText("This is Clear button.");
}而實作 copyContact() 需要用到 QClipboard ，因此 GUIDemo.cpp 的開頭要先引入這個程式庫 (library)
#include <QClipboard>
首先建立 QClipboard 的物件 (object) ，然後呼叫 setText() 並以 outputText 當參數 (parameter) ，這樣編碼結果就複製到系統剪貼簿了
void GUIDemo::copyContact() {
QClipboard *clipboard = QApplication::clipboard();
clipboard->setText(outputText);
display->setText("This is Copy button. Result is copied to clipboard.");
}完整的實作檔 GUIDemo.cpp 如下，記得要把 Clear 、 Copy 兩個按鈕建立 connect
#include <QtGui>
#include "GUIDemo.h"
#include <QFile>
#include <QDataStream>
#include <QClipboard>
GUIDemo::GUIDemo(QWidget *parent) : QWidget(parent) {
QLabel *input = new QLabel(tr("Input:"));
QLabel *output = new QLabel(tr("Output:"));
display = new QLabel(tr("something happened"));
inputField = new QLineEdit;
connect(inputField, SIGNAL(returnPressed()), this, SLOT(inputContact()));
outputField = new QLineEdit;
outputField->setReadOnly(true);
newButton = new QPushButton(tr("New"));
connect(newButton, SIGNAL(clicked()), this, SLOT(newEncrypt()));
loadButton = new QPushButton(tr("Load"));
connect(loadButton, SIGNAL(clicked()), this, SLOT(loadEncrypt()));
saveButton = new QPushButton(tr("Save"));
connect(saveButton, SIGNAL(clicked()), this, SLOT(saveEncrypt()));
encodeButton = new QPushButton(tr("Encode"));
connect(encodeButton, SIGNAL(clicked()), this, SLOT(encodeContact()));
decodeButton = new QPushButton(tr("Decode"));
connect(decodeButton, SIGNAL(clicked()), this, SLOT(decodeContact()));
clearButton = new QPushButton(tr("Clear"));
connect(clearButton, SIGNAL(clicked()), this, SLOT(clearContact()));
copyButton = new QPushButton(tr("Copy"));
connect(copyButton, SIGNAL(clicked()), this, SLOT(copyContact()));
QGridLayout *layout = new QGridLayout;
layout->addWidget(input, 0, 0);
layout->addWidget(inputField, 0, 1, 1, 6, 0);
layout->addWidget(output, 1, 0);
layout->addWidget(outputField, 1, 1, 1, 6, 0);
layout->addWidget(newButton, 2, 0);
layout->addWidget(loadButton, 2, 1);
layout->addWidget(saveButton, 2, 2);
layout->addWidget(encodeButton, 2, 3);
layout->addWidget(decodeButton, 2, 4);
layout->addWidget(clearButton, 2, 5);
layout->addWidget(copyButton, 2, 6);
layout->addWidget(display, 3, 0, 1, 7, 0);
setLayout(layout);
setWindowTitle(tr("GUIDemo"));
e = NULL;
}
void GUIDemo::newEncrypt() {
e = new Encrypt;
display->setText("This is New button. Encrypt code is " + s2q(e->getcArray()));
}
void GUIDemo::loadEncrypt() {
QFile file("encryptor");
if (file.open(QIODevice::ReadOnly)) {
QDataStream in(&file);
QString temp;
in >> temp;
if (e == NULL) {
e = new Encrypt;
e->setcArray(q2s(temp));
}
else {
e->setcArray(q2s(temp));
}
display->setText("This is Load button. Encrypt object is loaded.");
}
else {
display->setText("This is Load button. Encrypt object is not loaded.");
}
}
void GUIDemo::saveEncrypt() {
if (e != NULL) {
QFile file("encryptor");
file.open(QIODevice::WriteOnly);
QDataStream out(&file);
out << s2q(e->getcArray());
display->setText("This is Save button. Encrypt object is saved.");
}
else {
display->setText("This is Save button. There is no Encrypt Object.");
}
}
void GUIDemo::encodeContact() {
inputText = inputField->text();
if (inputText == "") {
display->setText("This is Encode button. No input string!!");
}
else {
if (e == NULL) {
display->setText("This is Encode button. No Encrypt object!!");
}
else {
outputText = s2q(e->toEncode(q2s(inputText)));
outputField->setText(outputText);
display->setText("This is Encode button. The result is above.");
}
}
}
void GUIDemo::decodeContact() {
inputText = inputField->text();
if (inputText == "") {
display->setText("This is Encode button. No input string!!");
}
else {
if (e == NULL) {
display->setText("This is Encode button. No Encrypt object!!");
}
else {
outputText = s2q(e->toDecode(q2s(inputText)));
outputField->setText(outputText);
display->setText("This is Decode button. The result is above.");
}
}
}
void GUIDemo::clearContact() {
inputText = "";
outputText = "";
inputField->setText("");
outputField->setText("");
display->setText("This is Clear button.");
}
void GUIDemo::copyContact() {
QClipboard *clipboard = QApplication::clipboard();
clipboard->setText(outputText);
display->setText("This is Copy button. Result is copied to clipboard.");
}
void GUIDemo::inputContact() {
inputText = inputField->text();
display->setText("Your input is '" + inputText + "'.");
}
QString GUIDemo::s2q(const string &s) {
return QString(QString::fromLocal8Bit(s.c_str()));
}
string GUIDemo::q2s(const QString &s) {
return string((const char *)s.toLocal8Bit());
}
/* 《程式語言教學誌》的範例程式
http://pydoing.blogspot.com/
檔名：GUIDemo.cpp
功能：示範 C++ 程式
作者：張凱慶
時間：西元 2012 年 10 月 */重新編譯執行， Clear ok
Copy 也 ok
好了，我們已經學完開發 GUIDemo 了，下一步是？
| 中英文術語對照 | |
|---|---|
| 類別 | class |
| 函數成員 | function member |
| 字串 | string |
| 程式庫 | library |
| 物件 | object |
| 參數 | parameter |
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