因此,這裏的類和超類,問題如下:如何將子類方法放入超類JLabel中?
TestDraw:
package project3;
import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class TestDraw extends MyShape
{
public static void main(String[] args)
{
DrawPanel panel = new DrawPanel();
JFrame application = new JFrame();
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
application.add(panel);
application.setSize(300,300);
application.setVisible(true);
JLabel southLabel = new JLabel(toString());
application.add(southLabel, BorderLayout.SOUTH);
}
}
MyShape的:
package project3;
import java.awt.Color;
public class MyShape
{
private int x1, y1, x2, y2;
private Color myColor;
public MyShape()
{
setX1(1);
setY1(1);
setX2(1);
setY2(1);
setMyColor(Color.BLACK);
}
public MyShape(int x1, int y1, int x2, int y2, Color myColor)
{
setX1(x1);
setY1(y1);
setX2(x2);
setY2(y2);
setMyColor(myColor);
}
public void setX1(int x1)
{
if(x1 >= 0 && x1 <= 300)
{
this.x1 = x1;
}
else
{
this.x1 = 0;
}
}
public int getX1()
{
return x1;
}
public void setY1(int y1)
{
if(y1 >= 0 && y1 <= 300)
{
this.y1 = y1;
}
else
{
this.y1 = 0;
}
}
public int getY1()
{
return y1;
}
public void setX2(int x2)
{
if(x2 >= 0 && x2 <= 300)
{
this.x2 = x2;
}
else
{
this.x2 = 0;
}
}
public int getX2()
{
return x2;
}
public void setY2(int y2)
{
if(y2 >= 0 && y2 <= 300)
{
this.y2 = y2;
}
else
{
this.y2 = 0;
}
}
public int getY2()
{
return y2;
}
public void setMyColor(Color myColor)
{
this.myColor = myColor;
}
public Color getMyColor()
{
return myColor;
}
public String toString()
{
return String.format("X1: %d, X2: %d, Y1: %d, Y2: %d, Color: %s", getX1(), getX2(),
getY1(), getY2(), getMyColor());
}
}
在課堂上TestDraw,我試圖把的toString從MyShape放到窗口的文本框中,但是當我做了「JLabel southLabel = new JLabel(toString());」它告訴我的toString()需要是靜態的。這一切都很好,除了當你讓toString靜態時,它想讓這個字符串中的gets爲靜態的,這是不好的......任何想法?
我試過在超類中放入toString(),但它給出了同樣的問題,試過問老師,但他說「看書」呃...已經兩個小時的閱讀章節,我還沒有找到第三次閱讀後的例子。
預先感謝您!
PS:答案很好,但解釋是首選!