Android:如何将参数传递给 AsyncTask 的 onPreExecute()? [英] Android: How can I pass parameters to AsyncTask's onPreExecute()?

问题描述

我使用 AsyncTask 来加载我作为内部类实现的操作.

I use an AsyncTask for loading operations that I implemented as an inner class.

在onPreExecute() 中，我显示了一个加载对话框，然后我再次将其隐藏在onPostExecute() 中.但是对于一些加载操作，我事先知道它们会很快完成，所以我不想显示加载对话框.

In onPreExecute() I show a loading dialog which I then hide again in onPostExecute(). But for some of the loading operations I know in advance that they will finish very quickly so I don't want to display the loading dialog.

我想通过一个可以传递给 onPreExecute() 的布尔参数来表明这一点，但显然由于某种原因 onPreExecute() 不接受任何参数.

I wanted to indicate this by a boolean parameter that I could pass to onPreExecute() but apparently for some reason onPreExecute() doesn't take any parameters.

显而易见的解决方法可能是在我的 AsyncTask 或外部类中创建一个成员字段，我必须在每次加载操作之前设置该成员字段，但这似乎不太优雅.有没有更好的方法来做到这一点?

The obvious workaround would probably be to create a member field in my AsyncTask or in the outer class which I would have to set before every loading operation but that does not seem very elegant. Is there a better way to do this?

推荐答案

您可以覆盖构造函数.类似的东西:

You can override the constructor. Something like:

private class MyAsyncTask extends AsyncTask<Void, Void, Void> {

    public MyAsyncTask(boolean showLoading) {
        super();
        // do stuff
    }

    // doInBackground() et al.
}

然后，在调用任务时，执行如下操作:

Then, when calling the task, do something like:

new MyAsyncTask(true).execute(maybe_other_params);

<小时>

这比创建成员变量更有用，因为它简化了任务调用.比较上面的代码:

---

this is more useful than creating member variables because it simplifies the task invocation. Compare the code above with:

MyAsyncTask task = new MyAsyncTask();
task.showLoading = false;
task.execute();

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