加载网络图片显示大图

本文主要是介绍加载网络图片显示大图，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

1.将图片的uri列表和下标传给ImagePagerActivity

public void imageBrower(int position, ArrayList<String> urls2) {Intent intent = new Intent(this, ImagePagerActivity.class);
    intent.putExtra(ImagePagerActivity.EXTRA_IMAGE_URLS, urls2);
    intent.putExtra(ImagePagerActivity.EXTRA_IMAGE_INDEX, position);
    this.startActivity(intent);
}

2.给ImagePagerActivity布局：layout里布局：

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

    <com.yangzi.homeimprovement.imagedemo.HackyViewPager
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/black"/>

    <TextView
        android:id="@+id/indicator"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="@android:color/transparent"
        android:gravity="center"
        android:text="@string/viewpager_indicator"
        android:textColor="@android:color/white"
        android:textSize="18sp"/>
    <!--  viewpager_indicator===>> string文件夹下: <string name="viewpager_indicator">%1$d/%2$d</string>-->
</FrameLayout>

3.关联布局--->写一个继承FragmentStatePagerAdapter的类显示图片

--->更新下标

/**
 * 图片查看器
 */
public class ImagePagerActivity extends FragmentActivity {private static final String STATE_POSITION = "STATE_POSITION";
    public static final String EXTRA_IMAGE_INDEX = "image_index";
    public static final String EXTRA_IMAGE_URLS = "image_urls";

    private ViewPager mPager;
    private int pagerPosition;
    private TextView indicator;

    @Override
    public void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);
        setContentView(R.layout.image_detail_pager);

        pagerPosition = getIntent().getIntExtra(EXTRA_IMAGE_INDEX, 0);
        ArrayList<String> urls = getIntent().getStringArrayListExtra(EXTRA_IMAGE_URLS);//intent传过来的显示大图的Uri

        mPager = (ViewPager) findViewById(R.id.pager);
        ImagePagerAdapter mAdapter = new ImagePagerAdapter(getSupportFragmentManager(), urls);
        mPager.setAdapter(mAdapter);
        indicator = (TextView) findViewById(R.id.indicator);

        CharSequence text = getString(R.string.viewpager_indicator, 1, mPager.getAdapter().getCount());
        indicator.setText(text);
        // 更新图片的下标
        mPager.setOnPageChangeListener(new OnPageChangeListener() {@Override
            public void onPageScrollStateChanged(int arg0) {}@Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {}@Override
            public void onPageSelected(int arg0) {CharSequence text = getString(R.string.viewpager_indicator, arg0 + 1, mPager.getAdapter().getCount());// 后面的参数填充参数1                indicator.setText(text);
            }});
        if (savedInstanceState != null) {pagerPosition = savedInstanceState.getInt(STATE_POSITION);
        }mPager.setCurrentItem(pagerPosition);
    }@Override
    public void onSaveInstanceState(Bundle outState) {outState.putInt(STATE_POSITION, mPager.getCurrentItem());
    }// 显示图片
    private class ImagePagerAdapter extends FragmentStatePagerAdapter {//当 Fragment 对应的数据集发生改变时,用它较好

        public ArrayList<String> fileList;

        public ImagePagerAdapter(FragmentManager fm, ArrayList<String> fileList) {super(fm);
            this.fileList = fileList;
        }@Override
        public int getCount() {return fileList == null ? 0 : fileList.size();//如果uri列表不为空，得到uriList的大小
        }@Override
        public Fragment getItem(int position) {String url = fileList.get(position);
            return ImageDetailFragment.newInstance(url);
        }}
}

4.显示图片这里用到了使用Android-Universal-Image-Loader 图片异步加载类库，

/**
 * 单张图片显示Fragment
 */
public class ImageDetailFragment extends Fragment {private String mImageUrl;
    private ImageView mImageView;
    private ProgressBar progressBar;
    private PhotoViewAttacher mAttacher;

    public static ImageDetailFragment newInstance(String imageUrl) {final ImageDetailFragment f = new ImageDetailFragment();

        final Bundle args = new Bundle();
        args.putString("url", imageUrl);
        f.setArguments(args);//Fragment不要用构造方法传参
        return f;
    }@Override
    public void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);
        //在构造方法里用setArguments传递过来的参数不为空，就得到大图的Url
        mImageUrl = getArguments() != null ? getArguments().getString("url") : null;
    }@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {final View v = inflater.inflate(R.layout.image_detail_fragment, container, false);
        mImageView = (ImageView) v.findViewById(R.id.image);
        mAttacher = new PhotoViewAttacher(mImageView);

        mAttacher.setOnPhotoTapListener(new PhotoViewAttacher.OnPhotoTapListener() {@Override
            public void onPhotoTap(View arg0, float arg1, float arg2) {getActivity().finish();
            }});

        progressBar = (ProgressBar) v.findViewById(R.id.loading);
        return v;
    }@Override
    public void onActivityCreated(Bundle savedInstanceState) {super.onActivityCreated(savedInstanceState);

        ImageLoader.getInstance().displayImage(mImageUrl, mImageView, new SimpleImageLoadingListener() {@Override
            public void onLoadingStarted(String imageUri, View view) {progressBar.setVisibility(View.VISIBLE);
            }@Override
            public void onLoadingFailed(String imageUri, View view, FailReason failReason) {String message = null;
                switch (failReason.getType()) {case IO_ERROR:message = "下载错误";
                        break;
                    case DECODING_ERROR:message = "图片无法显示";
                        break;
                    case NETWORK_DENIED:message = "网络有问题，无法下载";
                        break;
                    case OUT_OF_MEMORY:message = "图片太大无法显示";
                        break;
                    case UNKNOWN:message = "未知的错误";
                        break;
                }Toast.makeText(getActivity(), message, Toast.LENGTH_SHORT).show();
                progressBar.setVisibility(View.GONE);
            }@Override
            public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {progressBar.setVisibility(View.GONE);
                mAttacher.update();
            }});
    }
}