问题

我正在进行一个项目，我已经制作了一个菜单和一个`JPanel`，但现在我想在`JPanel`上绘图，并在我的游戏中添加一些HUD。

我提供了一张我游戏最终面板的图片，我想在左边添加一个带有玩家头像的蓝色矩形，在右边添加另一个矩形，显示动作、金钱等信息，但我想在构建它们时不使用我的Window类，而是在那里构建框架和所有JPanels。一般来说，既然玩家选择玩本地游戏，我希望能够在游戏进行时在此面板上绘制和擦除。

以下是我在游戏引擎类中使用的渲染方法：

```java
private void render() {
    BufferStrategy bs = this.getBufferStrategy();
    if (bs == null) {
        this.createBufferStrategy(1);
        return;
    }
    
    Graphics g = null;
    
    window.render();
    if (gameState == STATE.MultiPlay) {
        handler.render(g);
        hud.render(g);
    }
    if (gameState == STATE.LocalPlay) {
        handler.render(g);
        hud.render(g);
    }
}

我提供的代码是我在游戏引擎类中使用的渲染方法。通过我的游戏引擎，我使这个方法每秒循环10次，并且我希望在这里实例化Graphics类，然后继续进行其他类并绘制我想要在那个JPanel上绘制的所有内容。

我如何使用Graphics或类似方法在那个JPanel上绘制？

<details>
<summary>英文:</summary>

I am working on a project and i have already made a menu and a `JPanel` but now i want to draw over the `JPanel` and add some HUD to my game.

I am providing a picture with the final panel of my game and i want to add at the left a blue rectangle with the player heads and at the right another rectangle with actions, money etc but i want to construct them outside my Window class where i construct the frame and all of the JPanels. Generally now that the player has chosen to play a local game i want to be able to draw and erase on this panel as the game continues.
[![enter image description here][1]][1]

    private void render() {
    	BufferStrategy bs = this.getBufferStrategy();
    	if (bs == null) {
    		this.createBufferStrategy(1);
    		return;
    	}
    	
    	Graphics g = null;
    	
    	window.render();
    	if (gameState == STATE.MultiPlay) {
    		handler.render(g);
    		hud.render(g);
    	}
    	if (gameState == STATE.LocalPlay) {
    		handler.render(g);
    		hud.render(g);
    	}
    }

The code i provided is the render method i am using at my game engine class. With my game engine i have made this method circles 10 times per second and i wanted from here to instantiate the `Graphics` class and then go on with the other class and rendering everything i want to draw over that `JPanel`.

How can i draw over that `JPanel` using `Graphics` or something like that?

  [1]: https://i.stack.imgur.com/K0Qpv.png



</details>


# 答案1
**得分**: 1

你必须像这样使用Graphics对象：

    Graphics g = bs.getDrawGraphics();

我认为这会很有用，祝你有一个愉快的一天。

附注：如果你不想这样做，你也可以覆盖方法paint(Graphics g)，并使用这个参数。

<details>
<summary>英文:</summary>

You must use Graphics object like that:

    Graphics g= bs.getDrawGraphics();

I think it will be usefull, have a nice day.

PD: If you don&#39;t want to do that, you can also override the method paint(Graphcis g) and use the parameter.

</details>