java - J2ME 组合按键(一次多个按键)

Question

我正在使用这里的keyboard_key变量:

    //overrides the function keyPressed from "lcdui.Canvas"
    protected void keyPressed(int keyCode){
        keyboard_key = keyCode;
    }

检测手机上是否有按键被按下。

但它仅返回最近按下的键，并且不告诉是否可能按下任何其他键。请帮忙!

顺便说一句，我使用 NetBeans 7.0.1 作为 IDE。

Answer 1

...it returns only the key that is pressed most lately and it doesn't tell if any other key might be pressed

您在代码片段中使用它的方式，keyboard_key将始终只包含最近按下的键 - 只是因为它“没有空间”容纳更多的东西。

考虑使用Vector “记住”按下的不同键。

    //define in your class:
    Vector keysPressed = new Vector(); // to keep track of keys pressed

    //overrides the function keyPressed from "lcdui.Canvas"
    protected void keyPressed(int keyCode){
        keysPressed.addElement(new Integer(keyCode));
    }

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根据您的应用程序要求，考虑覆盖 keyRepeated与 keyPressed 一起。

<小时/>

如果您打算以游戏循环方式处理按键(“一次多个键”表明您可能考虑到这一点)，请考虑 lcdui.game.GameCanvas 提供的另一个选项API、方法getKeyStates() :

Gets the states of the physical game keys. Each bit in the returned integer represents a specific key on the device. A key's bit will be 1 if the key is currently down or has been pressed at least once since the last time this method was called. The bit will be 0 if the key is currently up and has not been pressed at all since the last time this method was called. This latching behavior ensures that a rapid key press and release will always be caught by the game loop, regardless of how slowly the loop runs...