我有一个循环，其中包含TextView.append（＆＃34;这里的前夕文本＆＃34;）在循环中如何将新字符串发送到TextView，就像所有显示的Eclipse控制台一样。我试图基本上循环运行并将每个输出实时添加到TextView的底部。
package com.example.assignment2_android;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Calendar;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Random;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.drm.DrmStore.Action;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class station extends Activity implements View.OnClickListener
{
Button run, clear, home;
EditText userinput;
TextView useroutput;
//LinkedList Customer Queue created here.
public static Queue<String> line = new LinkedList<String> ();
private static String time; //Time variable stored here.
//DateFormat variable stored here
private static DateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
private int intervals; //Random arrival integer stored here
private int cashiers; //User input of number of cashiers stored here
private int processing_time; //Random processing time stored here
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.reverser);
userinput = (EditText)findViewById(R.id.r_userinput);
useroutput = (TextView)findViewById(R.id.r_useroutput);
run = (Button)findViewById(R.id.button_run);
clear = (Button)findViewById(R.id.button_clear);
home = (Button)findViewById(R.id.button_home);
if (run != null)
{
run.setOnClickListener(this);
}
if (clear != null)
{
clear.setOnClickListener(this);
}
if (home != null)
{
home.setOnClickListener(this);
}
}
public void onClick(View view)
{
if (view == run)
{
cashiers = Integer.parseInt(userinput.getText().toString());//Get the Integer value the user inputs from the TextArea
arrival();
}
else if (view == clear)
{
userinput.setText("Line Cleared"); //Use string resource !
useroutput.setText("");
System.out.println("cleared"); // Use string resource
}
else if (view == home)
{
Intent a = new Intent(this, MainActivity.class);
startActivity(a);
}
}
private void arrival()
{
Thread arrival = new Thread();
{
useroutput.append("CUSTOMERS ARE COMING !!!! !!!!" + "\n" + "\n");
//Array of all the customer that will enter the queue.
String list[] = {"Naqi", "Monty", "Mohin", "Yasmin", "Maighjoo", "Ashish", "Paal", "Kevin", "Ruhail", "Tony"};
//2nd ArrayList which customer are added to and removed later on so no duplicates arise.
ArrayList<String> customer = new ArrayList<String>(Arrays.asList(list));
int array_customer_list = list.length; //Recording the number of customers in the array.
//While statement containing for loop add customers to the empty LinkedList object.
while (line.isEmpty())
{
for (int x = 0; x < array_customer_list; x++ )
{
try
{
Thread.sleep(ran_interval() * 1000); //Sleep method to hold the arrival time by 1-2 seconds.
int cus = (int) (Math.random() * customer.size()); //Random customer is picked here.
String new_cus = customer.get(cus); //New customer object is created ere.
line.add(new_cus); //Customer objects are added to the empty LinkedList queue.
customer.remove(cus);
//For loop statement to outputting the queue.
for (String s : line)
{
useroutput.append("[" + s.toString() + " " + "]" + "\n");; //Outputting each customer and using the ".name" method so customers are readable.
}
//Outputting the whole queue and stating who has joined the queue.
useroutput.append("\n" + "The queue has " + line.size() + " customers so far" + "\n" +
new_cus.toString() + " Has Joined the Queue " + " <=== WAITING" + "\n" + "\n");
}
catch(Exception a) //ERROR handler for sleep method.
{
System.out.println("Intervals error: " + a); //Outputting the ERROR message.
System.exit(0); //If ERROR found exit system.
}
}
}
useroutput.append("\n");
useroutput.append("CUSTOMERS ARE WAITING !!!! !!!!" + "\n" + "\n");
useroutput.append("Processing START !!!!" + "\n" + "\n");
while (!line.isEmpty()) //While statement with for loop to remove each customer from LinkedList queue.
{
try
{
String cus = line.remove(); //Method to remove customer from LinkedList queue.
String time = getTime();
Thread.sleep((processing_time() * 1000) / cashiers); //Sleep method to hold the processing by 1-3 seconds.
for (String s : line)
{
useroutput.append("[" + s.toString() + " " + "]" + "\n"); //Outputting each customer and using the ".name" method so customers are readable.
}
//Outputting the whole queue and stating who has joined the queue.
useroutput.append("\n" + "The queue has " + line.size() + " customers left" + "\n" +
cus.toString()+ " waited for " + time + " <=== SERVED" + "\n" + "\n");
}
catch(Exception a) //ERROR handler for sleep method.
{
System.out.println("Cashiers_wait error: " + a); //Outputting the ERROR message.
System.exit(0); //If ERROR found exit system.
}
}
useroutput.append("Processing FINISHED !!!!" + "\n");
System.out.println("working" + "\n" + "random arrival time is :" + intervals + "\n" +
"random processing time is :" + processing_time);
}; arrival.start();
};
static String getTime() //Time Constructor
{
Calendar cal = Calendar.getInstance();
time = dateFormat.format(cal.getTime()); //Getting the current system time.
return time; //Return time.
}
public int ran_interval()
{
Random rand = new Random(); //Random object created here.
int interval = this.intervals = rand.nextInt(2) + 1; //Random number between 1-2 is generated for customer arrival here.
return interval;
}
public int processing_time()
{
Random ran = new Random(); //Random object created here.
int time = this.processing_time = ran.nextInt(4) + 1; //Random number between 1-3 is generated for customer arrival here.
return time;
}
}
答案 0 :(得分：1)
您的arrival方法正在UI线程上运行。你应该把它放在AsyncTask中。此方法将成为doInBackground，并且每当您想要更新UI时（基本上，无论何时调用append），您都会调用publishProgress。然后重写onProgressUpdate以使EditText无效，这将导致它使用新文本重新绘制自己。
答案 1 :(得分：0)
似乎你在UI线程上使用了一个长时间运行的循环，这可能导致ANR并实际更新用户在结束后看到的内容。
可能的解决方案：
使用在后台运行的线程，每次要更新textView时，可以使用Handler实例（需要在UI线程上创建）发布将导致textview的消息/ runnables用新数据更新自己。