qt 文字滚动

//支持从左到右、从右到左以及左右一直滚动
//textmove.h
#ifndef TEXTMOVE_H
#define TEXTMOVE_H

#include 
#include 
#include 
#include 
#include 
#include 
#include 

class TextMove : public QWidget
{
    Q_OBJECT
public:
    enum MoveWay
    {
        LeftToRight,
        RightToLeft,
        LeftAndRight
    };

    explicit TextMove(QWidget *parent = nullptr);
    void setText(QString data);
    void paintEvent(QPaintEvent *event) override;
    void setMoveWay(MoveWay way);

    bool toLeft = true;
    QFont font;
    QTimer *timer;
    int x = 0;
    int y = 0;
    int step = 10;
    QString text = "中csgvtrhthergrgth！！";
    MoveWay moveWay = RightToLeft;
public slots:
    void updateText();

signals:

};
#endif // TEXTMOVE_H


//textmove.cpp
#include "textmove.h"

TextMove::TextMove(QWidget *parent) : QWidget(parent)
{
    timer = new QTimer(this);
    connect(timer, &QTimer::timeout, this, &TextMove::updateText);
    timer->start(100);

    font.setPixelSize(30);
}

void TextMove::setText(QString data)
{
    text = data;
}

void TextMove::paintEvent(QPaintEvent *)
{
    QPainter painter(this);
    QFontMetrics fm(font);
    int m_width  = fm.width(text);
    int m_height = fm.height();

    painter.setFont(font);/*
    if(width() > m_width)
    {
        painter.drawText((width()-m_width)/2, (height()-m_height)/2, text);
    }
    else*/
    {
        y = (height()-m_height) / 2;
        painter.drawText(x, y, text);

        if(moveWay == LeftToRight)
        {
            x += step;
            if(x > width())
                x = -m_width;
        }
        else if(moveWay == RightToLeft)
        {
            x -= step;
            if(x < -m_width)
                x = width();
        }
        else if(moveWay == LeftAndRight)
        {
            if(toLeft)
            {
                x -= step;
                if(x < -m_width)
                {
                    //x = width();
                    toLeft = false;
                }
            }
            else
            {
                x += step;
                if(x > width())
                    toLeft = true;
            }

        }
    }
}

void TextMove::setMoveWay(TextMove::MoveWay way)
{
    moveWay = way;
}

void TextMove::updateText()
{
    update();
}

//widget.h
#ifndef WIDGET_H
#define WIDGET_H

#include 
#include 


namespace Ui {
class Widget;
}

class Widget : public QMainWindow
{
    Q_OBJECT

public:
    explicit Widget(QMainWindow *parent = 0);
    ~Widget();

private:
    Ui::Widget *ui;
};

#endif // WIDGET_H


//widget.cpp
#include "widget.h"
#include "ui_widget.h"
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include "textmove.h"

Widget::Widget(QMainWindow *parent) :
    QMainWindow(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    setFixedSize(800, 480);
    setWindowTitle("文字滚动");

    TextMove *textMove = new TextMove(this);
    textMove->setGeometry(0, 0, 800, 100);

    TextMove *textMove1 = new TextMove(this);
    textMove1->setGeometry(0, 100, 800, 100);
    textMove1->setText("15516nhijnijmoiedvfrvrfeghtfgbhtg");
    textMove1->setMoveWay(TextMove::LeftToRight);

    TextMove *textMove2 = new TextMove(this);
    textMove2->setGeometry(0, 200, 800, 100);
    textMove2->setText("I L145614514jiojiojjojoopkcod！rgtrtercsdvdfvbbhbyhnrgv");
    textMove2->setMoveWay(TextMove::LeftAndRight);
}

Widget::~Widget()
{
    delete ui;
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190