下载并保存读取 url 数组的所有图像

Question

我正在尝试从 url 数组下载并保存所有图像，但问题是只有最后一张图像以名称 img7.jpg 保存。我不明白问题出在哪里？我希望所有的图片都被下载并保存为 img1.jpg、img2.jpg、img3.jpg 等名称。我需要在代码中的什么地方进行更改？

public class MainActivity extends ActionBarActivity {

ImageView imageView;

public static String[] stringArray = {"http://upload.wikimedia.org/wikipedia/en/9/90/Broken_Boundaries_of_Rohtas_Fort.jpg",
                                      "http://upload.wikimedia.org/wikipedia/en/a/a0/Rohtas_View_4.jpg",
                                      "http://upload.wikimedia.org/wikipedia/en/0/07/Rohtas_Fort_Gate.jpg",
                                      "http://upload.wikimedia.org/wikipedia/en/7/78/Rohtas_Village_View_2nd.jpg",
                                      "http://www.worldheritagesite.org/picx/w586.jpg",
                                      "http://wpcontent.answcdn.com/wikipedia/en/thumb/6/68/Rani_Mahal_Rohtas_Fort_2.jpg/930px-Rani_Mahal_Rohtas_Fort_2.jpg",
                                      "http://photos.wikimapia.org/p/00/01/75/75/69_big.jpg"};
int i = 0;

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

    imageView = (ImageView)findViewById(R.id.imageView1);

    for (String url : stringArray){

        Picasso.with(this)
        .load(url)
        .into(target);

        i++;
    }

}

private Target target = new Target() {

    @Override
    public void onBitmapLoaded(final Bitmap bitmap, Picasso.LoadedFrom from) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                File file = new File(Environment.getExternalStorageDirectory().getPath() +"/img"+i+".jpg");
                try {
                    file.createNewFile();
                    FileOutputStream ostream = new FileOutputStream(file);
                    bitmap.compress(CompressFormat.JPEG, 75, ostream);
                    ostream.close();
                    }
                catch (Exception e){
                    e.printStackTrace();
                    }
                }
            }).start();
        }

    @Override
    public void onBitmapFailed(Drawable errorDrawable) {

    }

    @Override
    public void onPrepareLoad(Drawable placeHolderDrawable) {
        if (placeHolderDrawable != null) {

        }
    }
};

}

Answer 1

在您的情况下，Picasso 会异步加载您的图像。

是什么意思

Picasso.with(this)
    .load(url)
    .into(target);

不会等到您的图片下载并存储到磁盘。所以，如果要保存图像，你的计数器 i 总是 (stringArray.length - 1)。

做这样的事情：

...
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    int index = 0;
    for (String url : stringArray) {
        Picasso.with(this)
                .load(url)
                .into(new IndexTarget(index));
        index++;
    }
}

class IndexTarget implements Target {

    private final int mIndex;

    public IndexTarget(int index){
        this.mIndex = index;
    }

    @Override
    public void onBitmapLoaded(final Bitmap bitmap, Picasso.LoadedFrom from) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                File file = new File(Environment.getExternalStorageDirectory().getPath() +"/img"+mIndex+".jpg");
                try {
                    file.createNewFile();
                    FileOutputStream ostream = new FileOutputStream(file);
                    bitmap.compress(Bitmap.CompressFormat.JPEG, 75, ostream);
                    ostream.close();
                }
                catch (Exception e){
                    e.printStackTrace();
                }
            }
        }).start();
    }

    @Override
    public void onBitmapFailed(Drawable errorDrawable) {

    }

    @Override
    public void onPrepareLoad(Drawable placeHolderDrawable) {

    }
}

下载并保存读取 url 数组的所有图像

Downloading and saving all the images reading the url Array

foreach

android

picasso