我正在尝试为我的手机编写一个非常基本的应用程序,只是为了让自己回到编程的摇摆中。我已经掌握了我想要做的框架和基础知识,我只是需要帮助一小部分让我失望。
在我的应用上,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然后退出,然后打印另一个活动的结果,但仅在对话框之后退出了。我目前正在使用一个线程,但我无法使其正常运行。
有没有人知道如何让它以我想要的方式运作?
这是我的活动文件来源:
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!
答案 0 :(得分:1)
使用AsyncTask。
一个例子:
http://javatech.org/2011/02/discovering-android-opening-a-progress-dialog-with-asynctask/
<强>更新强>
首先,你必须声明这样的类:
private class DecideTask extends AsyncTask<Void, Void, Boolean>
{
...
}
我不知道showDialog
和removeDialog
是如何运作的,但我会这样做:
显示对话框(在onPreExecute
中):
progressDialog = ProgressDialog.show(this, "Please wait...",
"Deciding...", true);
删除/取消对话框(在onPostExecute
中):
progressDialog.dismiss();
声明三种方法中的每一种:
protected Boolean doInBackground(Void... params)
protected void onPreExecute()
protected void onPostExecute(Boolean result)
应该这样做。