Question

任何人都可以告诉我为什么在我的GUI类中调用矩形时不会创建矩形。我想要做的就是根据我的矩形类创建一个矩形，但是我在下面的DataPanel类中得到了这些错误，并且无法找出原因。

Error:(21, 5) java: illegal start of expression
Error:(21, 15) java: illegal start of expression
Error:(21, 25) java: ';' expected
Error:(21, 36) java: ';' expected

public class DrawRooms{

int x,y,width,height;

public DrawRooms() {
    x = 0;
    y = 0;
    width = 0;
    height= 0;
}

public DrawRooms(int x, int y, int w, int h){
    this.x = x;
    this.y = y;
    this.width = w;
    this.height = h;
}

public void draw(Graphics2D g2d) {
    g2d.drawRect(x, y, width, height);
}


//sets x coordinate
public void setX(int x) {
    this.x = x;
}

//sets y coordinate
public void setY(int y) {
    this.y = y;
}

//sets width
public void setWidth(int w) {
    this.width = w;
}

//sets height
public void setHeight(int h) {
    this.height = h;
}

//gets x
public int getX() {
    return x;
}

//gets y
public int getY() {
    return y;
}

//gets width
public int getWidth() {
    return width;
}

//gets height
public int getHeight() {
    return height;
}

//toString to report values
@Override
public String toString(){
    String s = "\nX-Coordinate: " + getX() +
            "\nY-Coordinate: " + getY() +
            "Width: " + getWidth() +
             "Height : " + getHeight();
    return s;
}
}

public class DataPanel extends JPanel {

public DataPanel() {
    repaint();
    buildPanel();
    setVisible(true);
}

public void buildPanel() {
    DrawRooms room = new DrawRooms(50, 100, 600, 600);

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        room.draw(g2d);
     }
}
}

Answer 1

您已将paint-method放入buildPanel（..）{..}这是错误的   语法。

所以从buildPanel（...）
执行paint（...）

同样做点什么，

 DrawRooms room ;
public void buildPanel() {
    room = new DrawRooms(50, 100, 600, 600);

}

protected void paint(Graphics g) { // put this method out of buildPanel()
    super.paintComponent(g);
    Graphics2D g2d = (Graphics2D) g;
    room.draw(g2d);
 }

创建一个带GUI的矩形类（错误）

1 个答案: