我想根据是否显示虚拟键盘来改变布局。我已经搜索了API和各种博客,但似乎找不到任何有用的东西。

这可能吗?

谢谢!


当前回答

Nebojsa Tomcic的回答对我没有帮助。我有RelativeLayout与TextView和AutoCompleteTextView里面。我需要滚动TextView到底部时,键盘显示,当它被隐藏。为了实现这一点,我重写了onLayout方法,它对我来说很好。

public class ExtendedLayout extends RelativeLayout
{
    public ExtendedLayout(Context context, AttributeSet attributeSet)
    {
        super(context, attributeSet);
        LayoutInflater inflater = (LayoutInflater)
                context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        inflater.inflate(R.layout.main, this);
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b)
    {
        super.onLayout(changed, l, t, r, b);

        if (changed)
        {
            int scrollEnd = (textView.getLineCount() - textView.getHeight() /
                textView.getLineHeight()) * textView.getLineHeight();
            textView.scrollTo(0, scrollEnd);
        }
    }
}

其他回答

就像@amalBit的答案一样,注册一个全局布局的监听器,并计算dectorView的可见底部和建议底部的差值,如果差值大于某个值(猜测IME的高度),我们认为IME是up的:

    final EditText edit = (EditText) findViewById(R.id.edittext);
    edit.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            if (keyboardShown(edit.getRootView())) {
                Log.d("keyboard", "keyboard UP");
            } else {
                Log.d("keyboard", "keyboard Down");
            }
        }
    });

private boolean keyboardShown(View rootView) {

    final int softKeyboardHeight = 100;
    Rect r = new Rect();
    rootView.getWindowVisibleDisplayFrame(r);
    DisplayMetrics dm = rootView.getResources().getDisplayMetrics();
    int heightDiff = rootView.getBottom() - r.bottom;
    return heightDiff > softKeyboardHeight * dm.density;
}

高度阈值100是IME猜测的最小高度。

这适用于adjustPan和adjuststresize。

隐藏|显示事件键盘可以通过简单的hack在OnGlobalLayoutListener监听:

 final View activityRootView = findViewById(R.id.top_root);
        activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
            public void onGlobalLayout() {
                int heightDiff = activityRootView.getRootView().getHeight() - activityRootView.getHeight();

                if (heightDiff > 100) {
                    // keyboard is up
                } else {
                    // keyboard is down
                }
            }
        });

这里activityRootView是Activity的根视图。

Nebojsa的解决方案几乎对我有效。当我在一个多行EditText中单击时,它知道键盘被显示出来,但是当我开始在EditText中输入时,actualHeight和proposedHeight仍然是相同的,所以它不知道键盘仍然被显示出来。我做了一个轻微的修改,以存储最大高度,它工作得很好。下面是修改后的子类:

public class CheckinLayout extends RelativeLayout {

    private int largestHeight;

    public CheckinLayout(Context context, AttributeSet attributeSet) {
        super(context, attributeSet);
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        inflater.inflate(R.layout.checkin, this);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        final int proposedheight = MeasureSpec.getSize(heightMeasureSpec);
        largestHeight = Math.max(largestHeight, getHeight());

        if (largestHeight > proposedheight)
            // Keyboard is shown
        else
            // Keyboard is hidden

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}

如果你想从你的活动中处理IMM(虚拟)键盘窗口的显示/隐藏,你需要子类化你的布局并覆盖onMesure方法(这样你就可以确定你的布局的测量宽度和测量高度)。之后,通过setContentView()将子类布局设置为Activity的主视图。现在您将能够处理IMM显示/隐藏窗口事件。也许这听起来很复杂,但事实并非如此。代码如下:

main。xml

   <?xml version="1.0" encoding="utf-8"?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="horizontal" >
        <EditText
             android:id="@+id/SearchText" 
             android:text="" 
             android:inputType="text"
             android:layout_width="fill_parent"
             android:layout_height="34dip"
             android:singleLine="True"
             />
        <Button
             android:id="@+id/Search" 
             android:layout_width="60dip"
             android:layout_height="34dip"
             android:gravity = "center"
             />
    </LinearLayout>

现在在布局的Activity声明子类中(main.xml)

    public class MainSearchLayout extends LinearLayout {

    public MainSearchLayout(Context context, AttributeSet attributeSet) {
        super(context, attributeSet);
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        inflater.inflate(R.layout.main, this);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        Log.d("Search Layout", "Handling Keyboard Window shown");

        final int proposedheight = MeasureSpec.getSize(heightMeasureSpec);
        final int actualHeight = getHeight();

        if (actualHeight > proposedheight){
            // Keyboard is shown

        } else {
            // Keyboard is hidden
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}

您可以从代码中看到,我们在子类构造函数中为Activity扩展布局

inflater.inflate(R.layout.main, this);

现在只需设置Activity的子类布局的内容视图。

public class MainActivity extends Activity {

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        MainSearchLayout searchLayout = new MainSearchLayout(this, null);

        setContentView(searchLayout);
    }

    // rest of the Activity code and subclassed layout...

}

我是这样做的:

添加OnKeyboardVisibilityListener接口。

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

HomeActivity.java:

public class HomeActivity extends Activity implements OnKeyboardVisibilityListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sign_up);
    // Other stuff...
    setKeyboardVisibilityListener(this);
}

private void setKeyboardVisibilityListener(final OnKeyboardVisibilityListener onKeyboardVisibilityListener) {
    final View parentView = ((ViewGroup) findViewById(android.R.id.content)).getChildAt(0);
    parentView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

        private boolean alreadyOpen;
        private final int defaultKeyboardHeightDP = 100;
        private final int EstimatedKeyboardDP = defaultKeyboardHeightDP + (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP ? 48 : 0);
        private final Rect rect = new Rect();

        @Override
        public void onGlobalLayout() {
            int estimatedKeyboardHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, EstimatedKeyboardDP, parentView.getResources().getDisplayMetrics());
            parentView.getWindowVisibleDisplayFrame(rect);
            int heightDiff = parentView.getRootView().getHeight() - (rect.bottom - rect.top);
            boolean isShown = heightDiff >= estimatedKeyboardHeight;

            if (isShown == alreadyOpen) {
                Log.i("Keyboard state", "Ignoring global layout change...");
                return;
            }
            alreadyOpen = isShown;
            onKeyboardVisibilityListener.onVisibilityChanged(isShown);
        }
    });
}


@Override
public void onVisibilityChanged(boolean visible) {
    Toast.makeText(HomeActivity.this, visible ? "Keyboard is active" : "Keyboard is Inactive", Toast.LENGTH_SHORT).show();
  }
}

希望这对你有所帮助。