java - Android - 进度对话框退出操作

Question

我正在尝试为我的手机编写一个非常基本的应用程序，只是为了让自己重新投入到编程中。我已经掌握了我想做的事情的框架和基础知识，我只需要在一个让我很吃力的小部分上得到帮助。

在我的应用程序上，我有一个按钮。当按下该按钮时，我希望应用程序将一段文本更改为“决定...”，弹出一个不确定的进度条一两秒钟然后退出，然后打印另一个 Activity 的结果，但仅在对话框之后已经退出。我现在正在使用一个线程，但我无法让它正常运行。

有谁知道如何让它按照我想要的方式工作吗？

这是我的 Activity 文件源:

package com.bassios.decisionengine;

import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class DecisionEngineActivity extends Activity {

private ProgressDialog progressDialog;
public String decision;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

}

public void decide(View view) {
    TextView tv = (TextView) findViewById(R.id.Decision1);
    tv.setText("Deciding...");
    int a = generate();
    decision = decision(a);
    runDialog(1);
//        alterText();
}

public void alterText() {
    TextView tv = (TextView) findViewById(R.id.Decision1);
    tv.setText(decision);
}

private void runDialog(final int seconds) {
    progressDialog = ProgressDialog.show(this, "Please wait...", "Deciding...");
    new Thread(new Runnable() {

        public void run() {
            try {
                Thread.sleep(seconds * 1000);
                progressDialog.dismiss();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }).start();
}

public static int generate() {
    int a = (int) (Math.random() * 10) + 1;
    return a;
}

public static String decision(int a) {
    String decision = null;
    switch (a) {
        case 1:
            decision = "Yes";
            break;
        case 2:
            decision = "No";
            break;
        case 3:
            decision = "Yes";
            break;
        case 4:
            decision = "No";
            break;
        case 5:
            decision = "Yes";
            break;
        case 6:
            decision = "No";
            break;
        case 7:
            decision = "Yes";
            break;
        case 8:
            decision = "No";
            break;
        case 9:
            decision = "Yes";
            break;
        case 10:
            decision = "No";
            break;
    }
    return decision;
    }
}

谢谢!

Answer 1

使用 AsyncTask。

一个例子:

http://javatech.org/2011/02/discovering-android-opening-a-progress-dialog-with-asynctask/

更新:

首先，你必须像这样声明类:

private class DecideTask extends AsyncTask<Void, Void, Boolean>
{
...
}

我不知道 showDialog 和 removeDialog 是如何工作的，但我会这样做:

显示对话框(在 onPreExecute 中):

progressDialog = ProgressDialog.show(this, "Please wait...",
                "Deciding...", true);

删除/关闭对话框(在 onPostExecute 中):

progressDialog.dismiss();

分别声明三种方法:

protected Boolean doInBackground(Void... params)

protected void onPreExecute()

protected void onPostExecute(Boolean result)

应该这样做。