java - 图片标题 Android Viewpager

Question

我是 Android 编程新手。我有一个包含图像的画廊，当我单击一张图像时，应该会出现一个带有全屏图像和标题的 ViewPager，我可以滑动浏览整个画廊。我已经按照这个教程enter link description here唯一的区别是我的图像也存储在一个数组中，即标题。当我运行应用程序时，图库正在显示，但 Viewpager 是空的并且不滑动。我没有错误，我不知道应该出什么问题。预先感谢:)

FullScreenImageAdapter.java

package com.example.sherlockholmes.images;

import android.app.Activity;
import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;

import com.example.sherlockholmes.R;

public class FullScreenImageAdapter extends PagerAdapter {

    private Activity context;
    private LayoutInflater inflater;
    private int _position;
    private Integer[] mThumbIds;
    private String[] description;

    public FullScreenImageAdapter(Activity context,Integer[] mThumbIds,String[] description){
        this.context=context;
        this.mThumbIds =  mThumbIds;
        this.description = description;
    }


    @Override
    public int getCount() {
        return 0;
    }


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

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


        inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View viewLayout = inflater.inflate(R.layout.layout_fullscreen_image, container,
                false);

        ImageView imageView = (ImageView) viewLayout.findViewById(R.id.full_image);
        TextView textview = (TextView) viewLayout.findViewById(R.id.item_text);
        Button btnClose = (Button) viewLayout.findViewById(R.id.btnClose);
        imageView.setImageResource(mThumbIds[_position]);
        textview.setText(description[_position]);

        btnClose.setOnClickListener(new View.OnClickListener() {            
            @Override
            public void onClick(View v) {
                context.finish();
            }
        }); 

        ((ViewPager) container).addView(viewLayout,0);

        return viewLayout;
    }

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

    }

}

FullScreenViewActivity.java

package com.example.sherlockholmes.images;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.view.ViewPager;

import com.example.sherlockholmes.R;

public class FullScreenViewActivity extends Activity{


    private FullScreenImageAdapter adapter;
    private ViewPager viewPager;

     private Integer[] mThumbIds = {
                R.drawable.acd1, R.drawable.acd1,
               R.drawable.acd1, R.drawable.acd1,
               R.drawable.acd1, R.drawable.acd1,
               R.drawable.acd1, R.drawable.acd1,
        };

        private String[] description={
                "apple","pinaple","rose","strawberry",
                "orange","lemon","potato","banana"
        };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fullscreen_view);

        viewPager = (ViewPager) findViewById(R.id.pager);


        Intent i = getIntent();
        int position = i.getIntExtra("position", 0);

        adapter = new FullScreenImageAdapter(FullScreenViewActivity.this,mThumbIds,description);

        viewPager.setAdapter(adapter);

        // displaying selected image first
        viewPager.setCurrentItem(position);
    }
}

Answer 1

试试这个

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

而不是

 @Override
public int getCount() {
    return 0;
}

在您的FullScreenImageAdapter

并改变这个

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

}

与

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

并且还要改变这个

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

与

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

更新:您还需要更改此

  imageView.setImageResource(mThumbIds[_position]);
  textview.setText(description[_position]);

与

  imageView.setImageResource(mThumbIds[position]);
   textview.setText(description[position]);

在您的 FullScreenImageAdapter 中。这是因为您尚未初始化 _position，这就是为什么 View 分页器始终从位置 0 的数组中获取图像和标题。