首先嚐試離線磁碟快取,然後聯機並獲取映像
首先將 OkHttp 新增到 app 模組的 gradle 構建檔案中
compile 'com.squareup.picasso:picasso:2.5.2'
compile 'com.squareup.okhttp:okhttp:2.4.0'
compile 'com.jakewharton.picasso:picasso2-okhttp3-downloader:1.0.2'
然後建立一個擴充套件 Application 的類
import android.app.Application;
import com.squareup.picasso.OkHttpDownloader;
import com.squareup.picasso.Picasso;
public class Global extends Application {
@Override
public void onCreate() {
super.onCreate();
Picasso.Builder builder = new Picasso.Builder(this);
builder.downloader(new OkHttpDownloader(this,Integer.MAX_VALUE));
Picasso built = builder.build();
built.setIndicatorsEnabled(true);
built.setLoggingEnabled(true);
Picasso.setSingletonInstance(built);
}
}
將它新增到 Manifest 檔案,如下所示:
<application
android:name=".Global"
.. >
</application>
正常使用
Picasso.with(getActivity())
.load(imageUrl)
.networkPolicy(NetworkPolicy.OFFLINE)
.into(imageView, new Callback() {
@Override
public void onSuccess() {
//Offline Cache hit
}
@Override
public void onError() {
//Try again online if cache failed
Picasso.with(getActivity())
.load(imageUrl)
.error(R.drawable.header)
.into(imageView, new Callback() {
@Override
public void onSuccess() {
//Online download
}
@Override
public void onError() {
Log.v("Picasso","Could not fetch image");
}
});
}
});