Qt|qlabole change line spacing when displaying multiple lines

the front

The work has come to an end during this period , Want to optimize some imperfect functions , For example, the function of text line spacing .

for example ：QLabel When the control displays text , When there is too much text , The space between lines of text after auto wrapping is really too close , There will be a little flaw in beauty . therefore , To optimize this function , And then realize the function of setting line spacing .

development environment ：WIN10 + VS2017 + Qt5.14.2 64 position

The effect is as follows ：

The larger the font of the text , The smaller the line spacing , Here I set three font sizes , Set line spacing for different fonts .

Next , Specifically realize this function ~

Function realization

Small font ：22; Chinese font ：36; Big font 50

Because you need to show long text content , therefore , The first step is to let QLabel The displayed text can wrap automatically

1： Text wrapping

Set the fixed width of the display text , The fixed width at this time is 800

In the use of QLabel When , Want to wrap text automatically , You must control the fixed width of each row , Otherwise, the control cannot know how to wrap lines .

ui.labContent->setFiexedWidth(800);


Set the text content to be displayed

ui.labContent->setText(qsContent);


Set the size of automatic line feed and automatic text recognition

ui.labContent->setWordWarp(true);
ui.labContent->adjustSize();


Come here , Simple text auto wrap function has been realized . however , There is still a small problem , When we set more text content , And the larger the font , The tighter the spacing between rows . Aesthetically, it looks very ugly , Then the line spacing of the text plays a certain role at this time .

2： Text font settings

The previous effect has shown that there are three font styles , trumpet 、 medium , please 、 large

Set font style

// obtain ：QLabel Default font style
QFont fontContent = ui.labContent->font();
// Set up ： Font style ： Microsoft YaHei
fontContent->setFamily("Microsoft YaHei");
// Set up ： font size ：22
fontContent->setPixelSize(22);
// Set up ： Font color value
QPalette peContent;
peContent.setColor(QPalette::WindowText, QColor(51, 51, 51));
ui.labContent->setPalette(peContent);
// Font binding
ui.labContent->setFont(fontContent);


When we need to change the font size , Just replace

setPixelSize

The value in the , Specific font style settings , I recorded in my previous article , You can flip through , I won't elaborate here ~

3： Row spacing settings

It's the most important link , How to set the line spacing ~

When I implement this function , I also tried many methods , But they cannot be set successfully , Finally, I found that in Qt There is no explicit function to implement this function , I want to cry without tears , Comrades ！ Checked Qt Only then do I know , Want to realize the function of line spacing , Need to emulate html The style of .

Think of me C++ Development now has to learn html Style set , Very good , ha-ha ~

Set the height of the row spacing

<p style='line-height:40px;'></p>


After setting the line spacing, you will find , The text auto wrap function previously set doesn't work ！

stay html We want to wrap text automatically , The best way is to set the width of the text , Fill the whole 800 Width

<p style='width:100%;'></p>


Last , It should be noted that , stay html in <p> Tags do not recognize spaces indented in the first line , Want to show the style of indenting the first line , It must be set manually

<p style='white-space: pre-wrap'></p>


General settings

QString qsShow = &quot;<p style='line-height:40px; width:100% ; white-space: pre-wrap; '>&quot; + qsContent + &quot;</p>&quot;;


Come here , The function of setting text line spacing is realized , Isn't it strange ~

summary

Use html When setting the space between lines , Not just for QLabel Control , Like QLineEdit、QTextBrower etc. , Anything that can show the text content is applicable , It seems ,Qt It's really amazing haha ！

Concrete realization , as follows ：

Set different line spacing according to different fonts

I am a good citizen of China , a C++ Development program yuan ~