有時候需要判斷該軟鍵盤是否彈出：

方法1：
通過InputMethodManager類來判斷，但是isActive()判斷並不準確，有的時候你的鍵盤已經關閉了，但是依然返回ture。

InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE); //得到InputMethodManager的例項
if (imm.isActive()) {//如果開啟
 imm.toggleSoftInput(InputMethodManager.SHOW_IMPLICIT,InputMethodManager.HIDE
 
_NOT_ALWAYS
 );//關閉/開啟軟鍵盤
}

方法2：
通過判斷佈局中的RelativeLayout的高度，Activity設定：

android:windowSoftInputMode="adjustResize"

然後鍵盤彈出的時候RelativeLayout會被擠壓，從而高度發生變化，由此判斷軟鍵盤的狀態。
為了方便使用，我們自定義一個RelativeLayout:

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.RelativeLayout;

/**
 * 監聽軟鍵盤是否處於開啟狀態，使用方式RelativeLayout一樣
 */
 

public class KeyboardListenRelativeLayout extends RelativeLayout {

    private static final String TAG = KeyboardListenRelativeLayout.class.getSimpleName();

    public static final byte KEYBOARD_STATE_SHOW = -3;
    public static final byte KEYBOARD_STATE_HIDE = -2;
    public static final byte KEYBOARD_STATE_INIT = -1
 
;

    private boolean mHasInit = false;
    private boolean mHasKeyboard = false;
    private int mHeight;

    private IOnKeyboardStateChangedListener onKeyboardStateChangedListener;

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

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

    public KeyboardListenRelativeLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public void setOnKeyboardStateChangedListener(IOnKeyboardStateChangedListener onKeyboardStateChangedListener) {
        this.onKeyboardStateChangedListener = onKeyboardStateChangedListener;
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);
        Log.e(TAG, "b= " + b);
        if (!mHasInit) {
            mHasInit = true;
            mHeight = b;
            Log.e(TAG, "mHeight= " + b);
            if (onKeyboardStateChangedListener != null) {
                onKeyboardStateChangedListener.onKeyboardStateChanged(KEYBOARD_STATE_INIT);
            }
        } else {
            mHeight = mHeight < b ? b : mHeight;
        }

        if (mHasInit && mHeight > b) {                  //mHeight代表鍵盤的真實高度 ,b代表在視窗中的高度 mHeight>b 說明鍵盤隱藏
            mHasKeyboard = true;
            if (onKeyboardStateChangedListener != null) {
                onKeyboardStateChangedListener.onKeyboardStateChanged(KEYBOARD_STATE_SHOW);
            }
        }
        if (mHasInit && mHasKeyboard && mHeight == b) {  // mHeight = b 說明已經彈出
            mHasKeyboard = false;
            if (onKeyboardStateChangedListener != null) {
                onKeyboardStateChangedListener.onKeyboardStateChanged(KEYBOARD_STATE_HIDE);
            }
        }
    }

    public interface IOnKeyboardStateChangedListener {
        void onKeyboardStateChanged(int state);
    }
}

最後給mRelativeLayout設定一個監聽：

mRelativeLayout.setOnKeyboardStateChangedListener(new KeyboardListenRelativeLayout.IOnKeyboardStateChangedListener() {

            public void onKeyboardStateChanged(int state) {
                switch (state) {
                    case KeyboardListenRelativeLayout.KEYBOARD_STATE_HIDE://軟鍵盤隱藏
                        LogUtil.e("Keyboard", "軟鍵盤隱藏");
                        break;
                    case KeyboardListenRelativeLayout.KEYBOARD_STATE_SHOW://軟鍵盤顯示
                        LogUtil.e("Keyboard", "軟鍵盤顯示");
                        break;
                    default:
                        break;
                }
            }
        });

參考不詳…