Android全屏软键盘监听

Android开发的同学都知道，Android系统是不提供所谓的软键盘监听的，只提供了开关软键盘的相关api 如下

 /**
     * 开启软键盘
     * @param activity
     */
    public static void showKeybord(Activity activity,EditText et) {
        InputMethodManager imm =  (InputMethodManager)activity.getSystemService(Context.INPUT_METHOD_SERVICE);
        if(imm != null) {
             imm.showSoftInput(et, 0);
        }
    }
/**
     * 关闭软键盘
     * @param activity
     */
    public static void closeKeybord(Activity activity) {
        InputMethodManager imm =  (InputMethodManager)activity.getSystemService(Context.INPUT_METHOD_SERVICE);
        if(imm != null) {
            imm.hideSoftInputFromWindow(activity.getWindow().getDecorView().getWindowToken(), 0);
        }
    }

当开发使用的是Activity主题（Theme）是非全屏主题（fullscreen）非沉浸式的时候，可以通过DecordView 获取ViewTreeObserve去监听Layout变化，但是，如果当我们使用全屏主题的时候就会发现监听没任何作用了，网上抄的那些Utils也全都失效了

那我们能否在全屏的时候监听到软键盘的状态，以符合我们的开发业务的需求呢？

答案是肯定的

我们可以通过添加一个PopWindow 来解决无法监听软键盘的问题，直接上代码

public class FullScreenKeyboardHeightProvider extends PopupWindow implements OnGlobalLayoutListener {
    private Activity mActivity;
    private View mRootView;
    private HeightListener mHeightListener;
    private int mHeightMax; // 记录popup内容区的最大高度
    private int mKeyboardHeight;

    public FullScreenKeyboardHeightProvider(Activity activity) {
        super(activity);
        this.mActivity = activity;

        // 基础配置
        mRootView = new View(activity);
        setContentView(mRootView);

        // 监听全局Layout变化
        mRootView.getViewTreeObserver().addOnGlobalLayoutListener(this);
        setBackgroundDrawable(new ColorDrawable(0));

        // 设置宽度为0，高度为全屏
        setWidth(0);
        setHeight(LayoutParams.MATCH_PARENT);

        // 设置键盘弹出方式
        setSoftInputMode(LayoutParams.SOFT_INPUT_ADJUST_RESIZE);
        setInputMethodMode(PopupWindow.INPUT_METHOD_NEEDED);
    }

    public FullScreenKeyboardHeightProvider init() {
        if (!isShowing()) {
            final View view = mActivity.getWindow().getDecorView();
            // 延迟加载popupwindow，如果不加延迟就会报错
            view.post(new Runnable() {
                @Override
                public void run() {
                    showAtLocation(view, Gravity.NO_GRAVITY, 0, 0);
                }
            });
        }
        return this;
    }

    public FullScreenKeyboardHeightProvider setHeightListener(HeightListener listener) {
        this.mHeightListener = listener;
        return this;
    }

    @Override
    public void onGlobalLayout() {
        Rect rect = new Rect();
        mRootView.getWindowVisibleDisplayFrame(rect);
        if (rect.bottom > mHeightMax) {
            mHeightMax = rect.bottom;
        }
        // 两者的差值就是键盘的高度
        int currentKeyboardHeight = mHeightMax - rect.bottom;
        if (currentKeyboardHeight==mKeyboardHeight){
            return;
        }
//
        if (mHeightListener != null) {
            ValueAnimator valueAnimator = ValueAnimator.ofInt(mKeyboardHeight, currentKeyboardHeight);
            valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                @Override
                public void onAnimationUpdate(ValueAnimator animation) {
                    int animatedValue = (int) animation.getAnimatedValue();
                    mHeightListener.onHeightChanged(animatedValue);
                }
            });
            valueAnimator.addListener(new Animator.AnimatorListener() {
                @Override
                public void onAnimationStart(Animator animation) {

                }

                @Override
                public void onAnimationEnd(Animator animation) {
                    mKeyboardHeight = currentKeyboardHeight;
                }

                @Override
                public void onAnimationCancel(Animator animation) {

                }

                @Override
                public void onAnimationRepeat(Animator animation) {

                }
            });
            mHeightListener.onHeightChanged(mKeyboardHeight);
            valueAnimator.setDuration(200);
            valueAnimator.setInterpolator(new DecelerateInterpolator());
            valueAnimator.start();
        }
    }

    public interface HeightListener {
        void onHeightChanged(int height);
    }
 }

demo下载地址