当前位置：网站首页>20210306 reprint how to make TextEdit have background pictures

20210306 reprint how to make TextEdit have background pictures

2022-07-02 06:35:00 【qq_ forty million nine hundred and thirty-eight thousand one hu】

One 、 to QTextEdit Add background image , There are two ways ：

QTextEdit* iEdit = new QTextEdit();

1： Use style sheets ：

iEdit->setStyleSheet("background-image:url(:/bmp/DSCN1604.JPG)");

Be careful ： stay url() The first one in brackets “：” The colon must not be mistaken , Otherwise, it will not be displayed .

2： Use html

iEdit->setHtml("<body background=/"./bmp/DSCN1604.JPG/"> </body>");

Be careful ： At this time, you don't need to use it like the above “：” Colon , Just use the relative path directly .

(Notice： Before using the above two methods , Don't forget to add pictures to qrc In the resource file )

//-------------------------------------------------------------------------------------------------------------------------------------------------

In fact, the above two methods have the same display effect , So it's almost the same , But they both have two problems ：

Question 1 ： The picture cannot be scaled to match the size of the edit box , After all, the road strength of the picture is used here , We can't scale it . So it's best to set the size of the edit box to the same size as the image before using ！

Question two ： This is more serious .

When we write more than one screen ： The edit box needs to turn pages , You will find ： The picture will also turn the page .

as follows ： I put a background picture in the edit box ：

I certainly hope this picture will always be fixed behind the edit box , Without flipping , But if I use the above method to set a background picture , When writing more than one screen ： The picture will also flip the screen , Thus, the following situations may occur ：

or ： The picture will also be tiled many times behind the edit box , This is obviously not the effect we want .

The way to solve this problem is to put QTextEdit Set transparent , And then behind him widget Set the background picture on , So you OK 了

Set up QTextEdit Transparent approach

stay Qt All the problems in should be discussed in two systems , One is QWidget system , One is QGraphicsWidget system . This is no exception .

One ： about QWidget In terms of system ： That is to say, they all use QWidget And its derived classes . For this ： or QTextEdit The parent object of is also QWidget Or its derived class .

So what we have to do is ： Give Way QTextEdit Background becomes transparent , Then paint the picture at the position of the parent window behind it .

① Set up QTextEdit Transparent for the background ：

QPalette pl = iEdit->palette();

pl.setBrush(QPalette::Base,QBrush(QColor(255,0,0,0)));

iEdit->setPalette(pl);

namely ： Use a completely transparent brush to brush the background of the edit box ！

And its parent window brushes the picture at this position , The key is to note whether the parent window is a top-level window （ Whether it has a parent window ）, If so, be careful not to use setStyleSheet() To brush （ See the article for the reason http://blog.csdn.net/NRC_DouNingBo/archive/2010/05/07/5565212.aspx）.

Two ： about QGraphicsWidget system , Then use the following method to set , Here I use code directly ：

     MainWindow::MainWindow(QWidget *parent)
    : QGraphicsView(parent)
   {
      this->resize(360,640);
      iScene = new QGraphicsScene(0,0,360,640);

iEdit = new QTextEdit();
iEdit->resize(360,400);

     // The next paragraph is for my father view Brush picture
     QPalette palette;
     palette.setBrush(this->backgroundRole(),QBrush(QImage(":/bmp/dou.jpg")));
     this->setPalette(palette);

// This section is responsible for setting the edit box item The background is transparent

palette.setBrush(QPalette::Base,QBrush(QColor(255,0,0,0)));
iEdit->setPalette(palette);

QGraphicsProxyWidget* widget = iScene->addWidget(iEdit);

palette.setBrush(QPalette::Window,QBrush(QColor(255,0,0,0)));
widget->setPalette(palette);

this->setScene(iScene);
}

so , There is still a big difference , And it seems that some places are difficult to understand , In fact, the key here involves two issues , One is QWidget System and QGraphicsWidget What is the difference between systems ？ One is to use style sheets QPalette Set the background color / The difference between the two methods of pictures （ or ：QPalette Of setBrush() The first argument to the function is QPalette::Base form still ptr->backgrounRole() The difference between ）.

On these two questions , Please see

1：QWidget System and QGraphicsWidget The difference between systems

http://blog.csdn.net/NRC_DouNingBo/archive/2010/05/09/5571149.aspx

2：Qt How to use style sheets in QPalette And relevant precautions

http://blog.csdn.net/NRC_DouNingBo/archive/2010/05/09/5571187.aspx

This article is from CSDN Blog , Reprint please indicate the source ：http://blog.csdn.net/NRC_DouNingBo/archive/2010/05/09/5571088.aspx

Inherited address ：https://blog.51cto.com/seanyxie/1376013

原网站

版权声明
本文为[qq_ forty million nine hundred and thirty-eight thousand one hu]所创，转载请带上原文链接，感谢
https://yzsam.com/2022/183/202207020621390036.html