如何访问 ASyncTask 中的数组索引以进行 UI 更新？

Question

我有一个 ASyncTask 正在为我的 UserInterface 运行更新；但我不确定如何访问我的 AnalogInput[] 参数并在调用 publishProgress() 时检查我当前所在的索引；

private class AnalogUpdater extends AsyncTask<AnalogInput[], Float, Void> {

    // A callback method executed on non UI thread, invoked after
    // onPreExecute method if exists

    // Takes a set of parameters of the type defined in your class
    // implementation. This method will be
    // executed on the background thread, so it must not attempt to interact
    // with UI objects.
    @Override
    protected Void doInBackground(AnalogInput[]... params) {

        try {
            for (int i = 0; i < 15; i++) {
                publishProgress(params[0][i].getVoltage());
            }

        } catch (ConnectionLostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

    protected void onProgressUpdate(Float... f) {
        // Getting reference to the TextView tv_counter of the layout
        // activity_main
        final String str = String.format("Voltage: %.2f", f);
        final int v = Math.round(f[0] * 100);
        switch (idx // How can I get this index?) {
        case 1:
            analogInput0VoltageText.setText(str);
            analogInput0VoltageBar.setProgress(v);
            break;
        case 2:
            analogInput1VoltageText.setText(str);
            analogInput1VoltageBar.setProgress(v);
            break;
        case 3:
            analogInput2VoltageText.setText(str);
            analogInput2VoltageBar.setProgress(v);
            break;
        case 4:
            analogInput3VoltageText.setText(str);
            analogInput3VoltageBar.setProgress(v);
            break;
        case 5:
            analogInput4VoltageText.setText(str);
            analogInput4VoltageBar.setProgress(v);
            break;
        case 6:
            analogInput5VoltageText.setText(str);
            analogInput5VoltageBar.setProgress(v);
            break;
        case 7:
            analogInput6VoltageText.setText(str);
            analogInput6VoltageBar.setProgress(v);
            break;
        case 8:
            analogInput7VoltageText.setText(str);
            analogInput7VoltageBar.setProgress(v);
            break;
        case 9:
            analogInput8VoltageText.setText(str);
            analogInput8VoltageBar.setProgress(v);
            break;
        case 10:
            analogInput9VoltageText.setText(str);
            analogInput9VoltageBar.setProgress(v);
            break;
        case 11:
            analogInput10VoltageText.setText(str);
            analogInput10VoltageBar.setProgress(v);
            break;
        case 12:
            analogInput11VoltageText.setText(str);
            analogInput11VoltageBar.setProgress(v);
            break;
        case 13:
            analogInput12VoltageText.setText(str);
            analogInput12VoltageBar.setProgress(v);
            break;
        case 14:
            analogInput13VoltageText.setText(str);
            analogInput13VoltageBar.setProgress(v);
            break;
        case 15:
            analogInput14VoltageText.setText(str);
            analogInput14VoltageBar.setProgress(v);
            break;
        case 16:
            analogInput15VoltageText.setText(str);
            analogInput15VoltageBar.setProgress(v);
            break;
        }

    }

希望这很清楚；参考评论“我怎样才能得到这个索引？”在代码中。 }

Answer 1

您可以使用数组作为 asyncTask 的第二个参数（可能不是必需的，我不记得了）

private class AnalogUpdater extends AsyncTask<AnalogInput[], Float[], Void>

同时传递值、电压和索引（将索引转换为浮点数）

publishProgress(params[0][i].getVoltage(), (float)i);

稍后再使用（再次转换为 int）

protected void onProgressUpdate(Float... f)
{
    idx = (int)f[1];
}