点击按钮我正在调用openChannel函数
fetchXML是一个下载xml并设置变量的线程。虽然加载新视图需要2-5秒，但我可以看到进度条直接从0跳到100。
在openchannel中也是Toast ...它只在加载新视图后才加载，即在loadView之后加载...这会破坏它的写入目的。
Toast应该在showNews（）之前运行，但它会在它之后执行!!!!
为什么会延迟？ 任何帮助都得到了回报。
更新：
HandleXML.java
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserFactory;
public class HandleXML
{
private List<String> title = new ArrayList<String>();
private List<String> description = new ArrayList<String>();
private int totalNews = 0;
private String urlString = null;
private XmlPullParserFactory xmlFactoryObject = null;
public volatile boolean parsingComplete = true;
public HandleXML(String url)
{
this.urlString = url;
}
public List<String> getTitle()
{
return title;
}
public List<String> getDescription()
{
return description;
}
public int getTotalNews()
{
return totalNews;
}
public void parseXMLAndStoreIt(XmlPullParser myParser)
{
int event;
String text=null;
boolean isItem = false, isTitle = false;
try
{
event = myParser.getEventType();
while (event != XmlPullParser.END_DOCUMENT && totalNews < 10)
{
String name=myParser.getName();
switch (event)
{
case XmlPullParser.START_TAG:
if(name.equals("item"))
{
isItem = true;
}
break;
case XmlPullParser.TEXT:
text = myParser.getText();
text = text.replaceAll("<.*?>", "");
break;
case XmlPullParser.END_TAG:
if(name.equals("title") && isItem)
{
title.add(text);
isItem = false;
isTitle = true;
}
else if(name.equals("description") && isTitle)
{
description.add(text);
totalNews++;
isTitle = false;
}
break;
}
event = myParser.next();
}
parsingComplete = false;
}
catch (Exception e)
{
e.printStackTrace();
}
}
public void fetchXML()
{
Thread thread = new Thread(new Runnable(){
@Override
public void run()
{
try
{
URL url = new URL(urlString);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.connect();
InputStream stream = conn.getInputStream();
xmlFactoryObject = XmlPullParserFactory.newInstance();
XmlPullParser myparser = xmlFactoryObject.newPullParser();
myparser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES, false);
myparser.setInput(stream, null);
parseXMLAndStoreIt(myparser);
stream.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
});
thread.start();
}
}
MainActivity.java
import java.util.Date;
import java.util.List;
import java.util.Random;
import android.support.v7.app.ActionBarActivity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.res.Configuration;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity {
private int titleIds[] = {R.id.news1,R.id.news2,R.id.news3,R.id.news4,R.id.news5,R.id.news6,R.id.news7,R.id.news8,R.id.news9,R.id.news10};
private int descIds[] = {R.id.desc1,R.id.desc2,R.id.desc3,R.id.desc4,R.id.desc5,R.id.desc6,R.id.desc7,R.id.desc8,R.id.desc9,R.id.desc10};
private int colorIds[] = {R.color.DarkSalmon,R.color.DarkCyan,R.color.CornflowerBlue,R.color.BlueViolet,R.color.Goldenrod,R.color.Orchid,R.color.IndianRed,R.color.MediumAquamarine,R.color.LightCoral,R.color.Teal};
private ProgressBar progress;
private HandleXML obj = null;
private int currCnt = 0;
private int rand_color = new Random().nextInt(10);
private int rand_color2 = new Random().nextInt(10);
private boolean inMain = true, inChannel = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.newsScroll).setVisibility(View.GONE);
findViewById(R.id.newsChannels).setVisibility(View.VISIBLE);
progress = (ProgressBar) findViewById(R.id.progressBar);
progress.setMax(100);
}
public void showNews(String url)
{
currDesc = null;
currTitle = null;
obj = null;
progress.setProgress(30);
System.out.println("30 : "+new Date());
rand_color = new Random().nextInt(10);
rand_color2 = new Random().nextInt(10);
if(rand_color == rand_color2 && rand_color == 9)
rand_color2 = 0;
else if(rand_color == rand_color2)
rand_color2 = rand_color+1;
obj = new HandleXML(url);
obj.fetchXML();
progress.setProgress(50);
while(obj.parsingComplete);
progress.setProgress(70);
if(obj.getTitle().size() >0 && obj.getDescription().size() >0)
{
List<String> title = obj.getTitle();
List<String> description = obj.getDescription();
for(int i=0; i<obj.getTotalNews(); i++)
{
Button twT = (Button) findViewById(titleIds[i]);
twT.setText(title.get(i).trim());
twT.setBackground(new ColorDrawable(getResources().getColor(colorIds[rand_color])));
Button twD = (Button) findViewById(descIds[i]);
twD.setText(description.get(i).trim());
twD.setVisibility(View.GONE);
}
}
else
{
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("AHL NEWS ALERT")
.setMessage("FAILED TO LOAD NEWS !!")
.setCancelable(false)
.setNegativeButton("Close",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
}
progress.setProgress(90);
}
public void openChannel(View view)
{
progress.setProgress(10);
Toast.makeText(getBaseContext(), "Loading Please Wait ... ", Toast.LENGTH_SHORT).show();
showNews("http://example.com/news.xml");
progress.setProgress(100);
findViewById(R.id.newsScroll).setVisibility(View.VISIBLE);
findViewById(R.id.newsChannels).setVisibility(View.GONE);
findViewById(R.id.newsScroll).scrollTo(0, 0);
inMain = false;
inChannel = true;
}
}
答案 0 :(得分：1)
如果fetchXML正在使用线程，那么它应该如何工作。您将进度设置为10，然后调用loadNews调用其中有一个Thread的fetchXML。
为您创建一个Thread只需要几分之一秒。
我建议您使用AsyncTask，这样可以更好地控制获取和解析xml的过程。您应该从AsyncTask内部更新ProgressBar。有两种方法。一个是onProgressUpdate，另一个是onPostExecute。