java 'Background' 打开小看什么

Question

我正在制作一个游戏，游戏窗口只会打开到标题的大小。请让我知道需要进行哪些更改才能使“b.setSize(900,885)”正常工作。如果需要，我将更改或添加任意数量的代码。

 import java.awt.Color;
 import java.awt.Font;
 import java.awt.Graphics;
 import java.awt.Image;
 import java.awt.Rectangle;
 import java.awt.Window;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 import java.awt.event.KeyEvent;
 import java.awt.event.KeyListener;

 import javax.swing.*;


 public class Background extends JFrame implements KeyListener,    ActionListener{
 int platform1X = 300, platform1Y = 555, platform2X, platform2Y;
 Image image;
 public boolean isJumping = false;
 int playerx = 100, playery = 585, velX = 0, velY = 0;
 public boolean[] keyDown = new boolean[4];
 private int fallingSpeed = 0;
 private int gravity = 5;
 private int jumpPower = -30;


 public Background(){

 addKeyListener(this);
 setFocusable(true);
 setFocusTraversalKeysEnabled(false);
 keyDown[0] = false;
 keyDown[1] = false;
 keyDown[2] = false;
 keyDown[3] = false;

 }
  public void paint(Graphics g){
 if(!isOnGround()){
 fall();
}
 ImageIcon i = new ImageIcon("/Users/kairotieremorton/Documents/java   code/Kairo and Enoch Game/src/images/Backgroundsquareman.png");
image = i.getImage();
g.drawImage(image, 0, 0, 900, 700, null);
g.setColor(Color.BLUE);
g.fillRect(platform1X, platform1Y, 120, 20);
g.setColor(Color.RED);
g.fillRect(playerx, playery, 30, 30);
try {
Thread.sleep(40);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} 


repaint();
playery = playery + velY;
playerx = playerx + velX; 
}



public static void main(String[] args){
Background b = new Background();
b.setTitle("Game");
b.setSize(900,885);
b.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
b.setVisible(true);
}



public void keyPressed(KeyEvent e) {
int key = e.getKeyCode(); 
if(isOnGround() && key == KeyEvent.VK_SPACE){
 keyDown[0] = true; 

 jump();

 }
 //if(key == KeyEvent.VK_DOWN){ setvelY(5); keyDown[1] = true;}
 if(key == KeyEvent.VK_LEFT) { setvelX(-5); keyDown[2] = true;}
 if(key == KeyEvent.VK_RIGHT) { setvelX(5); keyDown[3] = true;}
 System.out.println(key);
 System.out.println(playerx);
 System.out.println(playery);
 }

 public void keyReleased(KeyEvent e) {
 int key = e.getKeyCode();

 if(key == KeyEvent.VK_SPACE){ keyDown[0] = false;}    //tempObject.setVelY(0);
//if(key == KeyEvent.VK_DOWN) keyDown[1] = false;//tempObject.setVelY(0);
 if(key == KeyEvent.VK_LEFT) keyDown[2] = false;//tempObject.setVelX(0);
 if(key == KeyEvent.VK_RIGHT) keyDown[3] = false; //tempObject.setVelX(0);

 //vertical movement
 if(!keyDown[0]) setvelY(0); System.out.println(isOnGround());

//horizontal movement
if(!keyDown[2] && !keyDown[3]) setvelX(0);
 }
public void keyTyped(KeyEvent e) {}

public void actionPerformed(ActionEvent e) {
 //playery = playery + velY;
 //playerx = playerx + velX; 
 //repaint();
 }
 public boolean isOnGround(){
 if(playery + (30 /2) >= 585) {
     return true;
 }
 return false;

 }

 public void fall(){
 playery = playery + fallingSpeed;
 fallingSpeed = fallingSpeed + gravity;

 }
 public void jump(){
 fallingSpeed = jumpPower;
 fall();
 }

 public void setvelX(int velX) {
 this.velX = velX;
 }
 public void setvelY(int velY) {
 this.velY = velY;
 }
 public float getvelX(){
 return velX;
 } 
 public float getvelY(){
 return velY;
 }
 public int getplayerx(){
 return playerx;
 }
 public int getplayery(){
 return playery;
 }
 public void setplayerx(int playerx) {
 this.playerx = playerx;
}
public void setplayery(int playery) {
this.playery = playery;
}
public Rectangle getBounds(){
return new Rectangle(getplatform1X(), platform1Y(), 120, 20);
}
public int getplatform1X(){
return platform1X;
}
public int platform1Y(){
return platform1Y;
}

public Rectangle getBoundsTop(){
return new Rectangle(getplayerx() + 10, getplayery(), 30 - 20, 5);
}
public Rectangle getBoundsBottom(){
return new Rectangle(getplayerx() + 10, getplayery() + 30 - 5, 30 - 20, 5);
}
public Rectangle getBoundsLeft(){
return new Rectangle(getplayerx(), getplayery()+10, 5, 30 -20);
}
public Rectangle getBoundsRigth(){
return new Rectangle(getplayerx() + 30 - 5, getplayery()+10, 5, 30 - 20);
}


}

Answer 1

好吧，这花了很多功夫，但是......

public Rectangle getBounds() {
    return new Rectangle(getplatform1X(), platform1Y(), 120, 20);
}

是你的问题。 JFrame#getBounds是 JFrame 用于返回组件位置和大小的方法，由于您已覆盖它，因此它现在将忽略您传递给 setSize 的任何值(直接或间接)

请阅读以下内容，了解为什么不应覆盖 JFrame 等顶级容器的 paint 的原因

• How can I set in the midst?
• Graphics rendering in title bar
• Java JFrame .setSize(x, y) not working?
• How to get the EXACT middle of a screen, even when re-sized

作为一般经验法则，您应该避免从 JFrame 扩展，因为您并没有真正向类添加任何新功能，它会将您锁定在单个用例中，并且基于您的经验可能会导致其他问题。

您应该从诸如 JPanel 之类的东西开始，并重写其 paintComponent 方法(并确保在执行任何操作之前调用 super.paintComponent定制绘画)

看看Painting in AWT and Swing和 Performing Custom Painting

您的绘制方法应该尽可能快地运行，因此您应该避免在绘制方法中加载资源，例如加载图像

Swing 是单线程的，因此在 paint 方法中调用 Thread.sleep 将导致整个程序停止，包括它响应用户新事件的能力.

我也不鼓励您使用 KeyListener，使用键绑定(bind) API 会更可靠。看看How to Use Key Bindings了解更多详情