java - 如何延迟在 TextView 中显示文本(逐字逐句)

Question

我希望 TextView 中的文本逐字显示，甚至逐字母显示，就像在大多数带有文本框的角色扮演游戏和冒险游戏中一样。一个很好的例子就是文本流应该是什么样子的游戏 phoenix wright ( http://youtu.be/2OOX2Gv0768?t=1m7s )

到目前为止我尝试过的是:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    String text = "test test test test";
    String[] split = text.split(" ");
    Deque<String> words = new LinkedList<String>();
    for (int i = 0; i<split.length; i++)
    {
        words.addLast(split[i]);
    }
    showNextWord(words);

}

public void showNextWord(final Deque<String> words)
{
    Handler handler = new Handler(); 
    handler.postDelayed(new Runnable() 
    { 
        public void run() 
        { 
            TextView t = (TextView) findViewById(R.id.textBox);
            t.append(words.pollFirst()+" ");
            if (words.size()>0)
                showNextWord(words);
        } 
    }, 500);
}

我在模拟器上测试过，它的性能似乎很低，如果我在显示每个字母后开始延迟，性能会更差。延迟不一致。

除此之外，我希望有一个更优雅的解决方案。也许有一些方法可以更灵活地应对延误？例如。一个句子后更大的延迟等等。

非常感谢!

Answer 1

public class Typewriter extends TextView {

private CharSequence mText;
private int mIndex;
private long mDelay = 500; //Default 500ms delay


public Typewriter(Context context) {
    super(context);
}

public Typewriter(Context context, AttributeSet attrs) {
    super(context, attrs);
}

private Handler mHandler = new Handler();
private Runnable characterAdder = new Runnable() {
    @Override
    public void run() {
        setText(mText.subSequence(0, mIndex++));
        if(mIndex <= mText.length()) {
            mHandler.postDelayed(characterAdder, mDelay);
        }
    }
};

public void animateText(CharSequence text) {
    mText = text;
    mIndex = 0;

    setText("");
    mHandler.removeCallbacks(characterAdder);
    mHandler.postDelayed(characterAdder, mDelay);
}

public void setCharacterDelay(long millis) {
    mDelay = millis;
}
}

然后像这样在你的 Activity 中使用上面的类:

    Typewriter writer = new Typewriter(this);
    //Add a character every 200ms
    writer.setCharacterDelay(200);
    writer.animateText("Sample String");