单击时按钮不会变为可见

Question

我有一个按钮，我想在每次单击图像视图时使其可见和不可见。 我试过设置不可见/可见，但它不起作用。

这是我的代码：

public class FullScreenImageAdapter extends PagerAdapter {

    Button btnClose;
    private Activity _activity;
    private ArrayList<String> _imagePaths;
    private LayoutInflater inflater;

    // constructor
    public FullScreenImageAdapter(Activity activity,
                                  ArrayList<String> imagePaths) {
        this._activity = activity;
        this._imagePaths = imagePaths;
    }

    @Override
    public int getCount() {
        return this._imagePaths.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == ((RelativeLayout) object);
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        TouchImageView imgDisplay;

        inflater = (LayoutInflater) _activity
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View viewLayout = inflater.inflate(R.layout.layout_fullscreen_image, container,
                false);
        hideBar();
        imgDisplay = (TouchImageView) viewLayout.findViewById(R.id.imgDisplay);
        btnClose = (Button) viewLayout.findViewById(R.id.btnClose);
        Picasso.with(_activity)
                .load(_imagePaths.get(position))
                .placeholder(R.drawable.loader)
                .fit()
                .centerCrop().into(imgDisplay);

        // close button click event
        btnClose.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                _activity.finish();
            }
        });

        imgDisplay.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                hideBar();
                hideButton();
            }
        });

        ((ViewPager) container).addView(viewLayout);

        return viewLayout;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        ((ViewPager) container).removeView((RelativeLayout) object);
    }

    public void hideBar() {
        View decorView = _activity.getWindow().getDecorView();
        int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_FULLSCREEN;
        decorView.setSystemUiVisibility(uiOptions);
    }

    public void hideButton() {
        if (btnClose.isShown()){
            btnClose.setVisibility(View.INVISIBLE);
        }else{
            btnClose.setVisibility(View.VISIBLE);
        }
    }
    }

这是我的 xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">

<com.example.shaka.we.ImageHelper.helper.TouchImageView
    android:id="@+id/imgDisplay"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:clickable="true"
    android:scaleType="fitCenter" />

<Button
    android:id="@+id/btnClose"
    android:layout_width="40dp"
    android:layout_height="40dp"
    android:layout_alignParentRight="true"
    android:layout_alignParentTop="true"
    android:layout_marginRight="15dp"
    android:layout_marginTop="15dp"
    android:background="@drawable/redx"
    android:paddingBottom="2dp"
    android:paddingLeft="10dp"
    android:paddingRight="10dp"
    android:paddingTop="2dp"
    android:visibility="invisible"/>

</RelativeLayout>

有人可以帮我吗？

Answer 1

public void hideButton() {
    if (btnClose.isShown()){
        btnClose.setVisibility(View.INVISIBLE);
    }else{
        btnClose.setVisibility(View.VISIBLE);
    }
}

调用isShown 不是检查视图是否显示或可见的好方法。检查其实际可见性，如下所示

public void hideButton() {
    if (btnClose.getVisibility() != View.VISIBLE){
        btnClose.setVisibility(View.VISIBLE);
    }else{
        btnClose.setVisibility(View.INVISIBLE);
    }
}

Answer 2

您可以使用view.getVisibility() 或view.isShow() 检查视图是否可见。但请记住：isShow() returns the visibility of this view and all of its ancestors. True if this view and all of its ancestors are visible 和 getVisibility() returns the visibility status for this view, which are VISIBLE, INVISIBLE, GONE. True if this view is visible。在您的情况下，该按钮具有始终可见的父级，因此 btnClose.isShown 为真，因此您在单击图像视图时始终执行 btnClose.setVisibility(View.INVISIBLE);。