android毕加索清除缓存

时间:2014-03-07 06:46:51

标签: android caching clear picasso

我正在使用Picasso来展示一个人的肖像,当protrait被更改时,我想清除这个用户的缓存(或所有用户的肖像缓存),这是我的代码,它不起作用,任何人都可以帮助我?

LruCache lruCache = new LruCache(context);
lruCache.clear();
Picasso picasso = new Picasso.Builder(context).memoryCache(lruCache).build();
picasso.load(portraitUrl).resize(50, 50).centerCrop().error(R.drawable.user_portrait).into(portaitView);

2 个答案:

答案 0 :(得分:8)

在毕加索的最新版本中,有一种新的无效方法,没有任何解决方法,所以我认为前面提到的自定义PicassoTools类现在已经过时了

Picasso.with(getActivity()).invalidate(file);

答案 1 :(得分:2)

我遇到了同样的问题,没有一个解决方案对我来说是可以接受的......所以我至少用反思做了一个解决方案。我没有使用裁剪,调整大小等等,所以只有在load(url)使用调整大小,裁剪,转换时,我的清晰函数才有效...但我自定义了完整的getKey函数,所以这至少应该是扩展清晰功能的一大帮助。或者只需公开getKey功能,将clear(uri)功能更改为clear(key) ...

我刚从源代码中复制了密钥功能并采用了它。

从我的工具类中获取picasso实例,一切都应该有效(而不是像我这样的上下文提供程序,你可以添加一个init函数,初始化PicassoTools类,例如应用程序上下文)。

只需使用以下工具类:

public class PicassoTools
{
private static Picasso picasso = null;
private static CustomLruCache lruCache = null;

private static CustomLruCache getCache()
{
    if (lruCache == null)
        lruCache = new CustomLruCache(MainApp.getAppContext());
    return lruCache;
}

public static Picasso getPicasso()
{
    if (picasso == null)
        picasso = new Picasso.Builder(MainApp.getAppContext()).memoryCache(getCache()).build();
    return picasso;
}

public static void clear(Uri uri)
{
    getCache().remove(getKey(uri));
}

public static void clearCache()
{
    getCache().clear();
    // Picasso.with(MainApp.getAppContext()).cache.clear();
}

public static void clearCache(Context c)
{
    getCache().clear();
    // Picasso.with(c).cache.clear();
}

private static final int KEY_PADDING = 50; // Determined by exact science.

private static String getKey(Uri uri)
{
    return getKey(uri, null, 0, 0, false, false, null);
}

private static String getKey(Uri uri, Integer resourceId, int targetWidth, int targetHeight, boolean centerCrop, boolean centerInside, List<Transformation> transformations)
{
    StringBuilder builder = new StringBuilder();
    if (uri != null)
    {
        String path = uri.toString();
        builder.ensureCapacity(path.length() + KEY_PADDING);
        builder.append(path);
    }
    else
    {
        builder.ensureCapacity(KEY_PADDING);
        builder.append(resourceId);
    }
    builder.append('\n');

    if (targetWidth != 0)
    {
        builder.append("resize:").append(targetWidth).append('x').append(targetHeight);
        builder.append('\n');
    }
    if (centerCrop)
    {
        builder.append("centerCrop\n");
    }
    else if (centerInside)
    {
        builder.append("centerInside\n");
    }

    if (transformations != null)
    {
        // noinspection ForLoopReplaceableByForEach
        for (int i = 0, count = transformations.size(); i < count; i++)
        {
            builder.append(transformations.get(i).key());
            builder.append('\n');
        }
    }

    return builder.toString();
}
}

扩展缓存类:

public class CustomLruCache extends LruCache
{
public CustomLruCache(Context context)
{
    super(context);
}

public CustomLruCache(int value)
{
    super(value);
}

@Override
public Bitmap get(String key)
{
    L.d(this, key);
    return super.get(key);
}

public void remove(String key)
{
    try
    {
        Bitmap value = map.remove(key);

        Field fieldSize = LruCache.class.getDeclaredField("size");
        fieldSize.setAccessible(true);
        Integer size = (Integer) fieldSize.get(this);
        size -= Utils.getBitmapBytes(value);
        fieldSize.set(this, size);

        Field fieldEvictionCount = LruCache.class.getDeclaredField("evictionCount");
        fieldEvictionCount.setAccessible(true);
        Integer evictionCount = (Integer) fieldEvictionCount.get(this);
        evictionCount++;
        fieldEvictionCount.set(this, evictionCount);

    }
    catch (IllegalArgumentException e)
    {
        L.e(this, e);
    }
    catch (IllegalAccessException e)
    {
        L.e(this, e);
    }
    catch (NoSuchFieldException e)
    {
        L.e(this, e);
    }
}
}

PS:灵感来自Invalidate cache in Picasso