QLine 類提供使用整數精度的 2D 嚮量。 更多...
| 頭： | #include <QLine> |
| qmake: | QT += core |
| QLine (int x1 , int y1 , int x2 , int y2 ) | |
| QLine (const QPoint & p1 , const QPoint & p2 ) | |
| QLine () | |
| QPoint | p1 () const |
| QPoint | p2 () const |
| int | x1 () const |
| int | x2 () const |
| int | y1 () const |
| int | y2 () const |
| QPoint | center () const |
| int | dx () const |
| int | dy () const |
| bool | isNull () const |
| void | setP1 (const QPoint & p1 ) |
| void | setP2 (const QPoint & p2 ) |
| void | setLine (int x1 , int y1 , int x2 , int y2 ) |
| void | setPoints (const QPoint & p1 , const QPoint & p2 ) |
| void | translate (const QPoint & offset ) |
| void | translate (int dx , int dy ) |
| QLine | translated (const QPoint & offset ) const |
| QLine | translated (int dx , int dy ) const |
| bool | operator!= (const QLine & line ) const |
| bool | operator== (const QLine & line ) const |
| QDataStream & | operator<< (QDataStream & stream , const QLine & line ) |
| QDataStream & | operator>> (QDataStream & stream , QLine & line ) |
A QLine describes a finite length line (or a line segment) on a two-dimensional surface. The start and end points of the line are specified using integer point accuracy for coordinates. Use the QLineF constructor to retrieve a floating point copy.
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The positions of the line's start and end points can be retrieved using the p1 (), x1 (), y1 (), p2 (), x2 ()，和 y2 () 函數。 dx () 和 dy () functions return the horizontal and vertical components of the line. Use isNull () to determine whether the QLine represents a valid line or a null line.
Finally, the line can be translated a given offset using the translate () 函數。
另請參閱 QLineF , QPolygon ，和 QRect .
Constructs a line object that represents the line between ( x1 , y1 ) 和 ( x2 , y2 ).
構造的綫條對象錶示綫條介於 p1 and p2 .
構造 null 綫條。
返迴綫條的起始點。
另請參閱 setP1 (), x1 (), y1 ()，和 p2 ().
返迴綫的終點。
另請參閱 setP2 (), x2 (), y2 ()，和 p1 ().
返迴綫條起始點的 X 坐標。
另請參閱 p1 ().
返迴綫終點的 X 坐標。
另請參閱 p2 ().
返迴綫條起始點的 Y 坐標。
另請參閱 p1 ().
返迴綫終點的 Y 坐標。
另請參閱 p2 ().
Returns the center point of this line. This is equivalent to ( p1 () + p2 ()) / 2, except it will never overflow.
該函數在 Qt 5.8 引入。
Returns the horizontal component of the line's vector.
另請參閱 dy ().
Returns the vertical component of the line's vector.
另請參閱 dx ().
返迴
true
if the line does not have distinct start and end points; otherwise returns
false
.
Sets the starting point of this line to p1 .
該函數在 Qt 4.4 引入。
Sets the end point of this line to p2 .
該函數在 Qt 4.4 引入。
Sets this line to the start in x1 , y1 and end in x2 , y2 .
該函數在 Qt 4.4 引入。
另請參閱 setP1 (), setP2 (), p1 ()，和 p2 ().
Sets the start point of this line to p1 and the end point of this line to p2 .
該函數在 Qt 4.4 引入。
另請參閱 setP1 (), setP2 (), p1 ()，和 p2 ().
Translates this line by the given offset .
這是重載函數。
Translates this line the distance specified by dx and dy .
Returns this line translated by the given offset .
該函數在 Qt 4.4 引入。
這是重載函數。
Returns this line translated the distance specified by dx and dy .
該函數在 Qt 4.4 引入。
返迴
true
若給定
line
is not the same as
this
line.
A line is different from another line if any of their start or end points differ, or the internal order of the points is different.
返迴
true
若給定
line
如同
this
line.
A line is identical to another line if the start and end points are identical, and the internal order of the points is the same.
寫入給定 line 到給定 stream 並返迴流引用。
另請參閱 序列化 Qt 數據類型 .
Reads a line from the given stream 進給定 line 並返迴流引用。
另請參閱 序列化 Qt 數據類型 .
