Android 在PagerAdapter类上实现浮动按钮

在这段代码中，我想在每次视图更改时使“Close”（关闭）按钮静止（浮动），如本例所示：

**XML**

还有我的页面碎片：

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
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.FrameLayout;

import java.util.ArrayList;

import com.myapplication.R;
import com.myapplication.helper.TouchImageView;


public class FullScreenImageAdapter extends PagerAdapter {

    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 == ((FrameLayout) object);
    }

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

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

        imgDisplay = (TouchImageView) viewLayout.findViewById(R.id.imgDisplay);
        btnClose = (Button) viewLayout.findViewById(R.id.btnClose);

        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;
        Bitmap bitmap = BitmapFactory.decodeFile(_imagePaths.get(position), options);
        imgDisplay.setImageBitmap(bitmap);

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

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

        return viewLayout;
    }

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

    }


}

导入android.app.Activity；
导入android.content.Context；
导入android.graphics.Bitmap；
导入android.graphics.BitmapFactory；
导入android.support.v4.view.PagerAdapter；
导入android.support.v4.view.ViewPager；
导入android.view.LayoutInflater；
导入android.view.view；
导入android.view.ViewGroup；
导入android.widget.Button；
导入android.widget.FrameLayout；
导入java.util.ArrayList；
导入com.myapplication.R；
导入com.myapplication.helper.TouchImageView；
公共类FullScreenImageAdapter扩展了PagerAdapter{
私人活动；
私有ArrayList_ImagePath；
私人充气机；
//建造师
公共FullScreenImageAdapter（活动，
ArrayList图像路径）{
这个。_活动=活动；
这是。_imagepath=imagepath；
}
@凌驾
public int getCount（）{
返回此项。_imagepath.size（）；
}
@凌驾
公共布尔值isViewFromObject（视图，对象）{
返回视图==（（框架布局）对象）；
}
@凌驾
公共对象实例化项（视图组容器，int位置）{
TouchImageView imgDisplay；
按钮关闭；
充气器=（充气器）\u活动
.getSystemService（上下文布局\充气机\服务）；
查看视图布局=充气机。充气（R.layout.layout\u全屏图像，容器，
假）；
imgDisplay=（TouchImageView）viewLayout.findViewById（R.id.imgDisplay）；
btnClose=（按钮）viewLayout.findViewById（R.id.btnClose）；
BitmapFactory.Options=new-BitmapFactory.Options（）；
options.inPreferredConfig=Bitmap.Config.ARGB_8888；
位图位图=位图工厂.decodeFile（_imagepath.get（位置），选项）；
设置图像位图（位图）；
//关闭按钮单击事件
btnClose.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
_activity.finish（）；
}
});
（（ViewPager）容器）。添加视图（viewLayout）；
返回视图布局；
}
@凌驾
公共项（视图组容器、int位置、对象）{
（（ViewPager）容器）。移除视图（（FrameLayout）对象）；
}
}

谢谢

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
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.FrameLayout;

import java.util.ArrayList;

import com.myapplication.R;
import com.myapplication.helper.TouchImageView;


public class FullScreenImageAdapter extends PagerAdapter {

    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 == ((FrameLayout) object);
    }

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

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

        imgDisplay = (TouchImageView) viewLayout.findViewById(R.id.imgDisplay);
        btnClose = (Button) viewLayout.findViewById(R.id.btnClose);

        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;
        Bitmap bitmap = BitmapFactory.decodeFile(_imagePaths.get(position), options);
        imgDisplay.setImageBitmap(bitmap);

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

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

        return viewLayout;
    }

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

    }


}