*我有一个加载一些文件并更新UI的类...查看结果需要一些时间，...所以我想添加一个加载栏或进度条。一些数据已被其他活动传递（Bundle extras1 = getIntent（）。getExtras（）;）。但我每个项目下载一张图片......我认为这需要更多时间。任何人都可以帮助我吗？
这是我的代码：
public class ShowSelectedEvents extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.viewdetailsevents);
Bundle extras1 = getIntent().getExtras();
String eventTitle = extras1.getString("eventTitle");
final String address = extras1.getString("address");
String date = extras1.getString("date");
String time = extras1.getString("time");
final String fix = extras1.getString("fix");
final String mobile = extras1.getString("mobile");
final String web = extras1.getString("web");
final String mail = extras1.getString("mail");
String imageLink = extras1.getString("imageLink");
final String videoLink = extras1.getString("videoLink");
// Add item image
Bitmap bitMap = null;
try {
bitMap = DownloadImage("imageLink);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ImageView imageItem = (ImageView) findViewById(R.id.imageItem);
imageItem.setImageBitmap(bitMap);
TextView viewTitle = (TextView) findViewById(R.id.viewTitle);
viewTitle.setText(eventTitle);
TextView viewDateTime = (TextView) findViewById(R.id.dateTime);
viewDateTime.setText("Event is on "+date +" @ "+ time);
// View Address
TextView viewAdd = (TextView) findViewById(R.id.viewAddress);
viewAdd.setTypeface(Typeface.defaultFromStyle(Typeface.ITALIC),Typeface.ITALIC);
viewAdd.setText(address);
// On click open Navigation
if (!(address.equals("-"))){
ImageView navigationIcon = (ImageView) findViewById(R.id.imageMapNavigation);
navigationIcon.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String url = "google.navigation:q="+address;
Intent i = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
startActivity(i);
}
});
}else{
Context context = getApplicationContext();
CharSequence text = "Address is incomplete!";
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
}
// View Phone number
TextView viewPhoneNumber = (TextView) findViewById(R.id.viewPhoneNumber);
viewPhoneNumber.setTypeface(Typeface.defaultFromStyle(Typeface.ITALIC),Typeface.ITALIC);
viewPhoneNumber.setText(fix);
// On click open call
if (!(fix.equals("-"))){
viewPhoneNumber.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String url = "tel:"+fix;
Intent i = new Intent(Intent.ACTION_CALL, Uri.parse(url));
startActivity(i);
}
});
}
//View Mobile number
TextView viewMobileNumber = (TextView) findViewById(R.id.viewMobileNumber);
viewMobileNumber.setTypeface(Typeface.defaultFromStyle(Typeface.ITALIC),Typeface.ITALIC);
viewMobileNumber.setText(mobile);
// on click call mobile number
if (!(mobile.equals("-"))){
viewMobileNumber.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String url = "tel:"+mobile;
Intent i = new Intent(Intent.ACTION_CALL, Uri.parse(url));
startActivity(i);
}
});
}
//View web url
TextView viewWeb = (TextView) findViewById(R.id.viewWeb);
viewWeb.setTypeface(Typeface.defaultFromStyle(Typeface.ITALIC),Typeface.ITALIC);
viewWeb.setText(web);
//on click open web browser
if (!(web.equals("-"))){
viewWeb.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(Intent.ACTION_VIEW, Uri.parse(web));
startActivity(i);
}
});
}
TextView viewMail = (TextView) findViewById(R.id.viewMailAddress);
viewMail.setTypeface(Typeface.defaultFromStyle(Typeface.ITALIC),Typeface.ITALIC);
viewMail.setText(mail);
if(!(mail.equals("-"))){
viewMail.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL, new String[] {mail});
emailIntent.putExtra(Intent.EXTRA_SUBJECT, "Contact from tamilpage.ch");
emailIntent.setType("text/plain");
startActivity(Intent.createChooser(emailIntent, "Send a mail ..."));
}
});
}
// On click play the video
if (!(address.equals("-"))){
ImageView videoIcon = (ImageView) findViewById(R.id.videoButton);
videoIcon.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent browserIntent = new Intent(Intent.ACTION_VIEW,
Uri.parse(videoLink));
startActivity(browserIntent);
}
});
}else{
Context context = getApplicationContext();
CharSequence text = "No advert video for this event";
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
}
}
private Bitmap DownloadImage(String url) throws Exception {
Bitmap bitmap = null;
InputStream in = null;
try {
in = OpenHttpConnection(url);
bitmap = BitmapFactory.decodeStream(in);
in.close();
} catch (IOException e1) {
e1.printStackTrace();
}
return bitmap;
}
private InputStream OpenHttpConnection(String url) throws Exception {
InputStream in = null;
int response = -1;
System.out.println("Nishi1");
URL url1 = new URL(url);
URLConnection conn = url1.openConnection();
if (!(conn instanceof HttpURLConnection))
throw new IOException("Not an HTTP connection");
try{
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK) {
in = httpConn.getInputStream();
System.out.println(in);
}
}
catch (Exception ex)
{
throw new IOException("Error connecting");
}
return in;
}
}
答案 0 :(得分：1)
所以我想添加一个加载栏或进度条
对于您的方法，您需要使用Threads。特别是我建议你看看
这两种方法都可以使用Threads。 AsyncTask比Handler更复杂，也是通用类型，因此提供更安全，更快速的工作。
你应该阅读一些教程，所以
在Vogella有非常棒的有用教程
答案 1 :(得分：0)
我会考虑使用AsyncTask。这是一个可以帮助您入门的链接：http://developer.android.com/reference/android/os/AsyncTask.html
答案 2 :(得分：0)
您希望这样做的方式是在ASyncTask中，该ASyncTask具有更新进度条的回调。我在下面提供了一个实际上没有做任何事情的样本。您可以在doInBackground（）中调用代码来调用下载，并从onProgressUpdate更新进度。
public class BackgroundAsyncTask extends
AsyncTask<Void, Integer, Void> {
int myProgress;
@Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
Toast.makeText(AndroidAsyncTaskProgressBar.this,
"onPostExecute", Toast.LENGTH_LONG).show();
}
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
Toast.makeText(AndroidAsyncTaskProgressBar.this,
"onPreExecute", Toast.LENGTH_LONG).show();
myProgress = 0;
}
@Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
while(myProgress<100){
myProgress++;
publishProgress(myProgress);
SystemClock.sleep(100);
}
return null;
}
@Override
protected void onProgressUpdate(Integer... values) {
// TODO Auto-generated method stub
progressBar.setProgress(values[0]);
}
}