android - 从 ListView 的自定义适配器中的 Intent 服务接收结果

Question

我想做的是以下内容

1. 我的自定义适配器布局中有一个按钮，它与服务器上的 php 脚本交互以在服务器上下载文件
2. 下载过程是通过在后台调用IntentService来处理的
3. 服务完成后，我想更新在 Activity 中启动的 ListView
4. 我被 Receiver 类困住了

到目前为止我的代码如下:

 @Override
public View getView(int position, View convertView, ViewGroup parent) {
    View view = convertView;
    if (view == null) {
        LayoutInflater vi;
        vi = LayoutInflater.from(getContext());
        if(IsRepository){
            view = vi.inflate(R.layout.filerepositorylayout, null);
        }
     }
      BindLayoutElemnts(view, position);
    return view;
  }

这里是调用 Intent 服务的地方:

 private void BindLayoutElemnts(View view, int position) {
      myFiles = (files) getItem(position);
       img_Download.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            Intent intent = new Intent(getContext(),DownloadService.class);
            intent.putExtra("FileID",""+myFiles.getID());
            intent.putExtra("FileName",myFiles.getName());
            context.startService(intent);
        }
    });
 }

调用 Activity

这里是调用Receiver的地方

    public class user_repositry extends AppCompatActivity implements  DownloadReceiver.Receiver {
 protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       myDownloadReceiver = new DownloadReceiver(new Handler());
       myDownloadReceiver.setReceiver(this);
 }

  @Override
public void onReceiveResult(int resultCode, Bundle resultData) {
    Toast.makeText(user_repositry.this, "Downloaded", Toast.LENGTH_SHORT).show();

}

Intent 服务代码:

 ResultReceiver rec;
 @Override
protected void onHandleIntent(Intent intent) {
      rec = intent.getParcelableExtra("DownloadReceiver");
}

 private void UpdateDBRecord() {
    HashMap<String, String>  PostData=new HashMap<String, String>();
    PostData.put("call","UpdateFile");
    PostData.put("ID", ""+file_ID);
    BackgroundWorker registerWorker= new BackgroundWorker(this,this,PostData);
    registerWorker.setShowLoadingMessage(false);
    registerWorker.execute(Helper.getPhpHelperUrl());
}

这个函数就是上面registerWorker在Post execute中调用的函数

 @Override
public void processFinish(String results) {
    Log.d("Download","Download DB updated");
    Bundle bundle = new Bundle();
    //bundle.putString("resultValue", "My Result Value. Passed in: " );
    // Here we call send passing a resultCode and the bundle of extras
    rec.send(Activity.RESULT_OK, bundle);
}

我现在被这个错误困住了:

Failed resolution of: Lcom/bassem/donateme/classes/DownloadReceiver;

我知道接收器没有被启动，但我似乎无法在我的逻辑中找到丢失的代码

感谢您的帮助

Answer 1

试试这个，

第 1 步: 在 Activity 中使用 ResultReceiver 创建结果处理程序

public ResultReceiver downloadReceiver = new ResultReceiver(new Handler()) {
    @Override
    protected void onReceiveResult(int resultCode, Bundle resultData) {
        super.onReceiveResult(resultCode, resultData);
        //Broadcast /send the result code in intent service based on your logic(success/error) handle with switch
        switch (resultCode) {
            case 1: {
                //Get the resultData and do your logic here
                //Update your list view item here
                break;
            }
            case 2: {
                //Get the resultData and do your logic here
                //Update your list view item here
                break;
            }
        }
    }
};  

第二步:将result handler放入intent并启动intent service

Intent intent = new Intent(getContext(), DownloadService.class);
intent.putExtra("receiver",downloadReceiver);

第 3 步:在服务类中处理 Intent (获取结果处理程序的值)

final ResultReceiver receiver;

@Override
protected void onHandleIntent(Intent intent) {
    receiver = intent.getParcelableExtra("receiver");
}

第 4 步:将数据发送/广播到结果处理程序

//based on your logic, change the result code and data

//Add your result data (success scenario)
Bundle bundle = new Bundle();
bundle.putString("result","Some text");
receiver.send(1,bundle);

//Add your result data (failure scenario)
receiver.send(0,bundle);