返回从非同步任务以MainActivity [英] Returning from Asynch Task to MainActivity

问题描述

我读了很多关于它，并试图很多东西，而无需更迭。但它似乎并不难可言，所以我想我缺少了一点东西。

I read a lot about it and tried many things, without having succes. But it doesn't seem hard at all, so I guess I am missing a little thing.

我得到了2班， MainActivity 和非同步任务类。结果
在 doInBackground 任务可以正常使用。
但是，当它完成，我想程序继续运行在某一点上我的 MainActivity

I got 2 classes, a MainActivity and an asynch task class.
the doInBackgroundtask is working perfectly. But when it is done, I want to program to continue at a certain point in my MainActivity

protected Integer doInBackground(Void... params) {
    try {
        Log.d("control", "ZipHelper.unzip() - File: " + _archive);
        ZipFile zipfile = new ZipFile(_archive);
        for (Enumeration<? extends ZipEntry> e = zipfile.entries(); e
                .hasMoreElements();) {
            ZipEntry entry = (ZipEntry) e.nextElement();
            unzipEntry(zipfile, entry, _outputDir);

        }
    } catch (Exception e) {
        Log.d("control", "ZipHelper.unzip() - Error extracting file "
                + _archive + ": " + e);
        setZipError(true);
    }
    return null;
}
protected void onPostExecute(Integer... result) {
    //Here something like MainActivity.showPicture();
}

我知道我必须做一些与 onPostExecute ，但我不知道究竟是什么。结果
所以我们说，我想显示吐司在我的 MainActivity 在非同步任务做？

I know I must do something with onPostExecute, but I don't know what exactly.
So let's say, I want to show a Toast in my MainActivity after asynch-task is done?

推荐答案

使用监听器接口。

示例：

Listener接口

Listener Interface

public interface AsyncTaskListener
{
    public void onTaskComplete();
}

ZipHelper类

public class ZipHelper extends AsyncTask<Void, Void, Integer>
{
    private String filename;
    private AsyncTaskListener listener;
    private File file;
    public ZipHelper(String filename, File file, AsyncTaskListener listener)
    {
        this.filename = filename;
        this.file = file;
        this.listener = listener;
    }

    @Override
    protected void onPreExecute()
    {
        //stuff here
    }

    @override
    protected Integer doInBackground(Void... params)
    {
        //Background stuff here
    }

    @Override
    protected void onPostExecute(Integer... result)
    {
        listener.onTaskComplete();
    }
}

MainActivity

public class MainActivity implements AsyncTaskListener
{
    public void onCreate(Bundle savedInstanceState)
    {
        super(savedInstanceState);
        setContentView(R.layout.main_activity);

        //Your stuff

        new ZipHelper(zip[0].mZipFileName, file, MainActivity.this).execute();
    }

    public void onTaskComplete()
    {
        //AsyncTask post stuff
    }
}

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