如何在键盘显示之前获取回调

Question

当键盘要弹出时，我需要进行回调。我必须做一些动作才能显示它。有可能吗？

Answer 1

将此添加到需要KeyboardListener的视图中：

public class MyView extends View {

    private boolean isKeyboardVisible = false;
    private boolean hasFocus = false;

    /**
     *  Screen ratio to determine keypad height.
     */
    public static final double SCREEN_RATIO = 0.15;

    public void setOnKeyboardListener(OnKeyboardListener onKeyboardListener) {
        this.mOnKeyboardListener = onKeyboardListener;
    }

    private OnKeyboardListener mOnKeyboardListener;

    public interface OnKeyboardListener {
        void onKeyboardOpen();

        void onKeyboardClosed();

    }

    public MyView(Context context) {
        super(context);

        getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                Rect r = new Rect();
                getWindowVisibleDisplayFrame(r);
                int screenHeight = getRootView().getHeight();

                int keypadHeight = screenHeight - r.bottom;
                if (keypadHeight > screenHeight * SCREEN_RATIO) {
                    // keyboard got opened
                    isKeyboardVisible = true;

                    if (mOnKeyboardListener != null) {
                        mOnKeyboardListener.onKeyboardOpen();
                    }
                } else if (hasFocus && isKeyboardVisible) {
                    // keyboard got closed
                    hasFocus = false;
                    isKeyboardVisible = false;

                    if (mOnKeyboardListener != null) {
                        mOnKeyboardListener.onKeyboardClosed();
                    }
                } else {
                    // keyboard is closed
                }

            }
        });

        setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                if (!hasFocus) {
                    hasFocus = true;
                    isKeyboardVisible = false;
                }
                return false;
            }
        });
    }
}

在您的活动中：

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

       MyView view = new MyView(getBaseContext());
       view.setOnKeyboardListener(new MyView.OnKeyboardListener() {
           @Override
           public void onKeyboardOpen() {

           }

           @Override
           public void onKeyboardClosed() {

           }
       });
}