Java 使用进度条?
在应用程序中,当用户单击按钮运行新活动时,它必须等待一段时间才能加载所有活动并启动,直到用户只能看到黑屏,所以我想在活动准备就绪之前放置进度条。 我该怎么做?Java 使用进度条?,java,android,Java,Android,在应用程序中,当用户单击按钮运行新活动时,它必须等待一段时间才能加载所有活动并启动,直到用户只能看到黑屏,所以我想在活动准备就绪之前放置进度条。 我该怎么做? 多谢各位 这是示例代码,请根据您的代码进行修改 import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import org.apache.http.HttpResponse; import org.apac
多谢各位 这是示例代码,请根据您的代码进行修改
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
public class ReadWebpageAsyncTask extends Activity {
private TextView textView;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
textView = (TextView) findViewById(R.id.TextView01);
}
private class DownloadWebPageTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
String response = "";
for (String url : urls) {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
try {
HttpResponse execute = client.execute(httpGet);
InputStream content = execute.getEntity().getContent();
BufferedReader buffer = new BufferedReader(
new InputStreamReader(content));
String s = "";
while ((s = buffer.readLine()) != null) {
response += s;
}
} catch (Exception e) {
e.printStackTrace();
}
}
return response;
}
@Override
protected void onPostExecute(String result) {
textView.setText(result);
}
}
public void readWebpage(View view) {
DownloadWebPageTask task = new DownloadWebPageTask();
task.execute(new String[] { "http://www.vogella.de" });
}
}
导入java.io.BufferedReader;
导入java.io.InputStream;
导入java.io.InputStreamReader;
导入org.apache.http.HttpResponse;
导入org.apache.http.client.methods.HttpGet;
导入org.apache.http.impl.client.DefaultHttpClient;
导入android.app.Activity;
导入android.os.AsyncTask;
导入android.os.Bundle;
导入android.view.view;
导入android.widget.TextView;
公共类ReadWebpageAsyncTask扩展活动{
私有文本视图文本视图;
/**在首次创建活动时调用*/
@凌驾
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
textView=(textView)findViewById(R.id.TextView01);
}
私有类下载WebPagetTask扩展异步任务{
@凌驾
受保护的字符串doInBackground(字符串…URL){
字符串响应=”;
for(字符串url:url){
DefaultHttpClient=新的DefaultHttpClient();
HttpGet HttpGet=新的HttpGet(url);
试一试{
HttpResponse execute=client.execute(httpGet);
InputStream内容=execute.getEntity().getContent();
BufferedReader buffer=新的BufferedReader(
新的InputStreamReader(内容));
字符串s=“”;
而((s=buffer.readLine())!=null){
响应+=s;
}
}捕获(例外e){
e、 printStackTrace();
}
}
返回响应;
}
@凌驾
受保护的void onPostExecute(字符串结果){
setText(结果);
}
}
公共作废阅读网页(查看){
DownloadWebPagetTask=新建DownloadWebPagetTask();
task.execute(新字符串[]{”http://www.vogella.de" });
}
}
两个可以帮助您的链接:和。请使用谷歌。尝试使用异步任务,我可以帮你