我需要做一件非常简单的事情-找出软件键盘是否显示。这在Android中可行吗?


当前回答

我的答案基本上与Kachi的答案相同,但我将它包装到一个很好的helper类中,以清理它在整个应用程序中的使用方式。

import android.app.Activity;
import android.app.Fragment;
import android.graphics.Rect;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;

/**
 * Detects Keyboard Status changes and fires events only once for each change
 */
public class KeyboardStatusDetector {
    KeyboardVisibilityListener visibilityListener;

    boolean keyboardVisible = false;

    public void registerFragment(Fragment f) {
        registerView(f.getView());
    }

    public void registerActivity(Activity a) {
        registerView(a.getWindow().getDecorView().findViewById(android.R.id.content));
    }

    public KeyboardStatusDetector registerView(final View v) {
        v.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                Rect r = new Rect();
                v.getWindowVisibleDisplayFrame(r);

                int heightDiff = v.getRootView().getHeight() - (r.bottom - r.top);
                if (heightDiff > 100) { // if more than 100 pixels, its probably a keyboard...
                    /** Check this variable to debounce layout events */
                    if(!keyboardVisible) {
                        keyboardVisible = true;
                        if(visibilityListener != null) visibilityListener.onVisibilityChanged(true);
                    }
                } else {
                    if(keyboardVisible) {
                        keyboardVisible = false;
                        if(visibilityListener != null) visibilityListener.onVisibilityChanged(false);
                    }
                }
            }
        });

        return this;
    }

    public KeyboardStatusDetector setVisibilityListener(KeyboardVisibilityListener listener) {
        visibilityListener = listener;
        return this;
    }

    public static interface KeyboardVisibilityListener {
        public void onVisibilityChanged(boolean keyboardVisible);
    }
}

你可以使用它来检测整个应用程序中的键盘变化,如下所示:

    new KeyboardStatusDetector()
            .registerFragment(fragment)  //register to a fragment 
            .registerActivity(activity)  //or register to an activity
            .registerView(view)          //or register to a view
            .setVisibilityListener(new KeyboardVisibilityListener() {
                @Override
                public void onVisibilityChanged(boolean keyboardVisible) {
                    if(keyboardVisible) {
                       //Do stuff for keyboard visible
                    }else {
                       //Do stuff for keyboard hidden
                    }
                }
            });

注意:只使用一个“寄存器”调用。它们都是一样的,只是为了方便

其他回答

你可以使用InputMethodManager。isActive方法,如果键盘可见则返回true:

    InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.isActive();

你也可以看到键盘在一个特定的视图中是否处于活动状态:

    imm.isActive(View v);

就计算机而言,这是永远的问题,但这个问题仍然令人难以置信地相关! 所以我把上面的答案结合起来,做了一些改进……

public interface OnKeyboardVisibilityListener {
    void onVisibilityChanged(boolean visible);
}

public final void setKeyboardListener(final OnKeyboardVisibilityListener listener) {
    final View activityRootView = ((ViewGroup) getActivity().findViewById(android.R.id.content)).getChildAt(0);
    activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

        private boolean wasOpened;

    private final Rect r = new Rect();

        @Override
        public void onGlobalLayout() {
            activityRootView.getWindowVisibleDisplayFrame(r);

            int heightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);
            boolean isOpen = heightDiff > 100;
            if (isOpen == wasOpened) {
                logDebug("Ignoring global layout change...");
                return;
            }

            wasOpened = isOpen;
            listener.onVisibilityChanged(isOpen);
        }
    });
}

这对我很管用。

检查元素的高度是不可靠的,因为一些键盘,如WifiKeyboard的高度为零。

相反,您可以使用showSoftInput()和hideSoftInput()的回调结果来检查键盘的状态。完整的细节和示例代码在

https://rogerkeays.com/how-to-check-if-the-software-keyboard-is-shown-in-android

if (keyopen())
{
                InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
                imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY,0);            
}

上面的函数是我用来检查键盘是否可见的。如果是,那我就关上。

下面显示了所需的两种方法。

首先,在onCreate中定义可工作的窗口高度。

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

//  add to onCreate method
    Rect rectgle= new Rect();
    Window window= getWindow();
    window.getDecorView().getWindowVisibleDisplayFrame(rectgle);
    sheight= rectgle.bottom;
//

} 

然后,添加一个布尔方法来获取该实例的窗口高度。如果它与原来的不匹配(假设您没有在此过程中更改它……),那么键盘是打开的。

public boolean keyopen()
{
    Rect rectgle= new Rect();
    Window window= getWindow();
    window.getDecorView().getWindowVisibleDisplayFrame(rectgle);
    int curheight= rectgle.bottom;

    if (curheight!=sheight)
    {
        return true;
    }
    else
    {
        return false;
    }
}

Frotz !

也有解决方案与系统嵌入,但它只适用于API >= 21 (Android L)。说你有BottomNavigationView,这是线性布局的孩子,你需要隐藏它时,键盘显示:

> LinearLayout
  > ContentView
  > BottomNavigationView

你所需要做的就是以这样的方式扩展LinearLayout:

public class KeyboardAwareLinearLayout extends LinearLayout {
    public KeyboardAwareLinearLayout(Context context) {
        super(context);
    }

    public KeyboardAwareLinearLayout(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public KeyboardAwareLinearLayout(Context context,
                                     @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public KeyboardAwareLinearLayout(Context context, AttributeSet attrs,
                                     int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    @Override
    public WindowInsets onApplyWindowInsets(WindowInsets insets) {
        int childCount = getChildCount();
        for (int index = 0; index < childCount; index++) {
            View view = getChildAt(index);
            if (view instanceof BottomNavigationView) {
                int bottom = insets.getSystemWindowInsetBottom();
                if (bottom >= ViewUtils.dpToPx(200)) {
                    // keyboard is shown
                    view.setVisibility(GONE);
                } else {
                    // keyboard is hidden
                    view.setVisibility(VISIBLE);
                }
            }
        }
        return insets;
    }
}

这个想法是,当键盘显示时,系统insets被改变为相当大的.bottom值。