为什么软键盘不会在WebView的Fragment中显示

webview.setOnTouchListener(new View.OnTouchListener() {
    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
            case MotionEvent.ACTION_UP:
                if (!v.hasFocus()) {
                    v.requestFocus();
                }
                break;
        }
        return false;
    }
});  

private class MyWebView extends WebView {

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

// Note this!
@Override
public boolean onCheckIsTextEditor() {
    return true;
}

@Override
public boolean onTouchEvent(MotionEvent ev)     {
    switch (ev.getAction())         {
        case MotionEvent.ACTION_DOWN:
        case MotionEvent.ACTION_UP:
            if (!hasFocus())
                requestFocus();
        break;
    }

    return super.onTouchEvent(ev);
}
}

<com.example.view.MyWebView
    android:id=\"@+id/vw\"
    android:layout_width=\"wrap_content\"
    android:layout_height=\"wrap_content\" />

MyWebView webView = (MyWebView) parent.findViewById(R.id.vw);
webView.setVerticalScrollBarEnabled(false);
webView.setHorizontalScrollBarEnabled(false);
webView.requestFocus(View.FOCUS_DOWN);
webView.loadUrl(url);