ViewPager$LayoutParams 不能转换为 RelativeLayout$LayoutParams

Question

我有一个启用了 View Pager 和 Touch View 功能的网格 View Gallery 应用程序。 .当用户单击网格视图上的图像时，它会全屏打开。当我单击 GridView 应用程序中的任何图像时，应用程序会崩溃，这就是我在日志中得到的结果
(android.support.v4.view.ViewPager$LayoutParams cannot be cast to android.widget.RelativeLayout$LayoutParams)。请帮忙。

这是我的MainActivity 班级：

public class MainActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Set title for the GridView
        setTitle("GridView");
        // Get the view from grid_view.xml
        setContentView(R.layout.activity_main);

        // Set the images from ImageAdapter.java to GridView
        GridView gridview = (GridView) findViewById(R.id.grid);
        gridview.setAdapter(new ImageAdapter(this));

        // Listening to GridView item click
        gridview.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v, int position, long id) {

                // Launch ImageViewPager.java on selecting GridView Item
                Intent i = new Intent(getApplicationContext(), ImageViewPager.class);

                // Show a simple toast message for the item position
                Toast.makeText(MainActivity.this, "" + position, Toast.LENGTH_SHORT).show();

                // Send the click position to ImageViewPager.java using intent
                i.putExtra("id", position);

                // Start ImageViewPager
                startActivity(i);
            }
        });
    }

这是我的ImageAdapter 班级：

public class ImageAdapter extends BaseAdapter  {

    private Context context;

    public String Images[] = {("http://www.fashionlady.in/wp-content/uploads/2016/03/creative-punjabi-mehndi-design-2016.jpg"),
            ("https://lumiere-a.akamaihd.net/v1/images/uk_toystory_chi_woody_n_5b5a006f.png?region=0,0,300,300"),
            ("https://lumiere-a.akamaihd.net/v1/images/open-uri20150422-20810-10n7ovy_9b42e613.jpeg"),
            ("http://www.wetpaint.com/wp-content/uploads/2015/11/toy-story-20th-anniversary.jpg")};


    public ImageAdapter(Context c) {
        context = c;

    }

    @Override
    public int getCount() {
        return Images.length;
    }

    @Override
    public Object getItem(int position) {
        return Images[position];
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageview = new ImageView(context);

        imageview.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageview.setLayoutParams(new GridView.LayoutParams(240, 240));

        Picasso.with(context).load(Images[position]).into(imageview);

        return imageview;
    }
}

这是我的 FullImageActivity 课程，应该打开一个完整的图像：

public class FullImageActivity extends AppCompatActivity {

    TouchImageView img;

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

        setContentView(R.layout.activity_full_image);


        Intent i = getIntent();

        List<ImageView> images = new ArrayList<>();
        int position = i.getExtras().getInt("id");
        ImageAdapter adapter = new ImageAdapter(this);
        ImagePagerAdapter pageradapter = new ImagePagerAdapter(images);

        img = (TouchImageView) findViewById(R.id.img);
        images.add(img);
        ViewPager viewpager = (ViewPager)findViewById(R.id.pager);
        viewpager.setAdapter(pageradapter);
        viewpager.setCurrentItem(position);
        ViewGroup.LayoutParams params = img.getLayoutParams();
        params.width = ViewGroup.LayoutParams.MATCH_PARENT;
        params.height = 100;
        img.requestLayout();

        img.setMaxZoom(4f);
        Picasso.with(getApplicationContext()).load(adapter.Images[position]).into(img);

    }
}

这是我的ImagePagerAdapter 班级：

public class ImagePagerAdapter extends PagerAdapter {

    private List<ImageView> images;

    public ImagePagerAdapter(List<ImageView> images) {
        this.images = images;
    }



    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        ImageView imageView = images.get(position);
        container.addView(imageView);
        return imageView;
    }

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

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

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

完全错误：-

FATAL EXCEPTION: main
                                                                           Process: com.wahid.mehndidesignfinal, PID: 8100
                                                                           java.lang.ClassCastException: android.support.v4.view.ViewPager$LayoutParams cannot be cast to android.widget.RelativeLayout$LayoutParams
                                                                               at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:457)
                                                                               at android.view.View.measure(View.java:18788)
                                                                               at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                               at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
                                                                               at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139)
                                                                               at android.view.View.measure(View.java:18788)
                                                                               at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                               at android.support.v7.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:393)
                                                                               at android.view.View.measure(View.java:18788)
                                                                               at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                               at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
                                                                               at android.view.View.measure(View.java:18788)
                                                                               at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                               at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
                                                                               at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
                                                                               at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
                                                                               at android.view.View.measure(View.java:18788)
                                                                               at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                               at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
                                                                               at com.android.internal.policy.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2643)
                                                                               at android.view.View.measure(View.java:18788)
                                                                               at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2100)
                                                                               at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1216)
                                                                               at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1452)
                                                                               at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107)
                                                                               at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013)
                                                                               at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
                                                                               at android.view.Choreographer.doCallbacks(Choreographer.java:670)
                                                                               at android.view.Choreographer.doFrame(Choreographer.java:606)
                                                                               at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
                                                                               at android.os.Handler.handleCallback(Handler.java:739)
                                                                               at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                               at android.os.Looper.loop(Looper.java:148)
                                                                               at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                               at java.lang.reflect.Method.invoke(Native Method)
                                                                               at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                               at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Answer 1

使用

RelativeLayout.LayoutParams params = img.getLayoutParams();

而不是

ViewGroup.LayoutParams params = img.getLayoutParams();