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

这个想法是,如果你需要隐藏你的键盘,同时检查软输入状态,使用以下解决方案:

public boolean hideSoftInput() {
    InputMethodManager imm = (InputMethodManager) getSystemService(Activity.INPUT_METHOD_SERVICE);
    return imm.hideSoftInputFromWindow(mViewPager.getWindowToken(), 0);
}

如果在隐藏之前显示键盘,则此方法返回true。

这可能不适合生产环境,因为它会打开键盘。注意,类似函数返回的布尔值在API中没有指定,因此是不可靠的。参考这里的文档…

https://developer.android.com/reference/android/view/inputmethod/InputMethodManager showSoftInput (% 20 int, android.view.View % 20 android.os.resultreceiver)

public boolean showSoftInput (View view, 
            int flags, 
            ResultReceiver resultReceiver)

注意,这个方法接受一个ResultReceiver。它可以得到结果:result_unchanged_shows, RESULT_UNCHANGED_HIDDEN, result_shows,或RESULT_HIDDEN。如果得到result_unchanged_show,则键盘是可见的。如果你需要它保持关闭如果它已经关闭了,你需要关闭它。

这是我的解决方案,它很有效。而不是寻找像素大小,只是检查内容视图的高度是否改变:

// Scroll to the latest comment whenever the keyboard is shown
commentsContent.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

        private int oldHeight;

        @Override
        public void onGlobalLayout() {
            int newHeight = commentsContent.getMeasuredHeight();
            if (newHeight < oldHeight) {
                // Check for the keyboard showing in case the height difference
                // is a result of orientation change
                if (isSoftKeyboardShowing(CommentsActivity.this)) {
                    // Keyboard is showing so scroll to the latest comment
                    scrollToLatestComment();
                }
            }
            oldHeight = newHeight;
        }

    });


public static boolean isSoftKeyboardShowing(Activity activity) {
    InputMethodManager inputMethodManager = (InputMethodManager) activity.getSystemService(Activity.INPUT_METHOD_SERVICE);
    return inputMethodManager.isActive();
}

不要编写任何硬代码。最好的方法是,你必须调整你的视图,而Get Focus on EditText与键盘显示。 您可以使用下面的代码将活动上的resize属性添加到清单文件中。

android: windowSoftInputMode = adjustResize”

试试这个:

final View activityRootView = getWindow().getDecorView().getRootView();
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        Rect r = new Rect();
        //r will be populated with the coordinates of your view that area still visible.
        activityRootView.getWindowVisibleDisplayFrame(r);

        int heightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);
        if (heightDiff < activityRootView.getRootView().getHeight() / 4 ) { // if more than 100 pixels, its probably a keyboard...
             // ... do something here ... \\
        }
    }
});