AsyncTask Example Android with ProgressBar
MainActivity.java
activity_main.xml
AndroidManifest.xml do not forget INTERNET uses-permission !!!!!!!
package com.asynctaskexample;
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.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.TextView;
public class MainActivity extends Activity {
private TextView textView;
private ProgressBar progressBar;
private DownloadWebPageTask mTask = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.TextView01);
downloadPage();
}
// AsyncTask <TypeOfVarArgParams , ProgressValue , ResultValue> .
private class DownloadWebPageTask extends AsyncTask<String, Integer, String> {
@Override
protected void onPreExecute() {
//textView.setText("Hello !!!");
progressBar = (ProgressBar) findViewById(R.id.progressBar1);
progressBar.setVisibility(View.VISIBLE);
super.onPreExecute();
}
@Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
}
@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) {
progressBar.setVisibility(View.INVISIBLE);
textView.setText(result);
}
}
private void downloadPage() {
if (mTask != null
&& mTask.getStatus() != DownloadWebPageTask.Status.FINISHED) {
mTask.cancel(true);
}
// execute(String[]) you can put array of links to web pages, or array of Integer[]
// if first param is Integer[] etc.
mTask = (DownloadWebPageTask) new DownloadWebPageTask()
.execute(new String[] { "//android.okhelp.cz/android-market.html",
"//android.okhelp.cz/android-market.html" });
}
@Override
protected void onDestroy() {
super.onDestroy();
if (mTask != null
&& mTask.getStatus() != DownloadWebPageTask.Status.FINISHED) {
mTask.cancel(true);
mTask = null;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
activity_main.xml
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ProgressBar
android:id="@+id/progressBar1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/TextView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
</LinearLayout>
AndroidManifest.xml do not forget INTERNET uses-permission !!!!!!!
<uses-permission android:name="android.permission.INTERNET" />
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Example source code for Android Developers
// clickable TextView
public TextView createTextView(String sText, Context con){
TextView b = null;
try {
b = new TextView (con);
b.setTextSize(15.0f);
b.setTextColor(Color.rgb( 0, 0, 200));
b.setOnClickListener(this);
b.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT));
b.setText(sText);
//tr.addView(b, 60,30);
} catch (Exception e) {
e.printStackTrace();
return b;
}
return b;
}
/*****************/
public void onClick(View view) {
try {
String s = ((TextView) view).getText().toString();
}
catch (Exception e1) {
e1.printStackTrace();
}
}
/***********/
// if you want restore in TextView after chagne of orientation
// you have to put code to Manifest.xml android:configChanges
activity android:name=".main"
android:label="@string/app_name"
android:configChanges="keyboardHidden|orientation" //this line important !!!!!!!
Cross Button in EditText Android for deleting clearing text in EditText Example source code:
Example allow delete text in EditText by cross button, or do Button click performance.
main.xml type your package name and class
Put into drawable folder cross and ok image.
CustomEditText.java
YourActivity.java
//android.okhelp.cz/wiktionary-aplikace-pro-android/
Example allow delete text in EditText by cross button, or do Button click performance.
main.xml type your package name and class
Put into drawable folder cross and ok image.
<cz.okhelp.wiktionary.CustomEditText
android:id="@+id/editTextZadejSlovo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="2"
android:ems="10"
android:hint="TypeAndPressGreen"
android:singleLine="true"
android:lines="1"
android:maxLines="1"
android:drawableLeft="@drawable/cross"
android:drawableRight="@drawable/ok" />
<!--button is invisible 0 height 0 width for performance click on button in EditText-->
<Button
android:id="@+id/btnGO"
android:layout_width="0sp"
android:layout_height="0sp"
android:layout_weight="0"
android:text="GO" />
CustomEditText.java
package cz.okhelp.wiktionary; // your package name
import android.content.Context;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.widget.Button;
import android.widget.EditText;
public class CustomEditText extends EditText
{
private Drawable dLeft,dRight;
private Rect lBounds,rBounds;
private static Button btnOk;
public CustomEditText(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public CustomEditText(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomEditText(Context context) {
super(context);
}
@Override
public void setCompoundDrawables(Drawable left, Drawable top,
Drawable right, Drawable bottom)
{
if(left !=null) {
dLeft = left;
}
if(right !=null){
dRight = right;
}
super.setCompoundDrawables(left, top, right, bottom);
}
@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_ENTER) {
btnOk.requestFocus();
btnOk.performClick();
}
return super.onKeyUp(keyCode, event);
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
final int x = (int)event.getX();
final int y = (int)event.getY();
if(event.getAction() == MotionEvent.ACTION_UP && dLeft!=null) {
lBounds = dLeft.getBounds();
int n1 = this.getLeft();
int n2 = this.getLeft()+lBounds.width();
int n3 = this.getPaddingTop();
int n4 = this.getHeight()-this.getPaddingBottom();
// leva strana
if( x>=(this.getLeft())
&& x<=(this.getLeft()+lBounds.width())
&& y>=this.getPaddingTop()
&& y<=(this.getHeight()-this.getPaddingBottom()))
{
this.setText("");
event.setAction(MotionEvent.ACTION_CANCEL);//use this to prevent the keyboard from coming up
}
}
if(event.getAction() == MotionEvent.ACTION_UP && dRight!=null)
{
rBounds = dRight.getBounds();
int n1 = this.getRight()-rBounds.width();
int n2 = this.getRight()-this.getPaddingRight();
int n3 = this.getPaddingTop();
int n4 = this.getHeight()-this.getPaddingBottom();
// prava strana
if(x>=(this.getRight()-rBounds.width()) && x<=(this.getRight()-this.getPaddingRight())
&& y>=this.getPaddingTop() && y<=(this.getHeight()-this.getPaddingBottom()))
{
btnOk.requestFocus();
btnOk.performClick();
event.setAction(MotionEvent.ACTION_CANCEL);//use this to prevent the keyboard from coming up
}
}
return super.onTouchEvent(event);
}
@Override
protected void finalize() throws Throwable
{
dRight = null;
rBounds = null;
super.finalize();
}
public void setBtnOk(Button btnOk) {
this.btnOk = btnOk;
}
public Button getBtnOk() {
return btnOk;
}
}
YourActivity.java
//onCreate
Button mBtnGO = (Button)findViewById(R.id.btnGO);
CustomEditText mEditZadani = (CustomEditText)this.findViewById(R.id.editTextZadejSlovo);
mEditZadani.setBtnOk(mBtnGO);
mBtnGO.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// do stuff for signInButtonClick
}
});
//android.okhelp.cz/wiktionary-aplikace-pro-android/
If You create new xml file with prefix _ , for example _style.xml and You to clean project (Project->Clean), than package in folder project\gen will deleted with R.java class and new R.java not be created.
For to solving this problem You have to rename file without prefix _ as style.xml or name what You need and rebuild project.
If some ID cannot be resolved or is not a field get error occurence
You have to delete import android.R; in Activity.class if was inserted,
when this error is displayed.
For to solving this problem You have to rename file without prefix _ as style.xml or name what You need and rebuild project.
If some ID cannot be resolved or is not a field get error occurence
You have to delete import android.R; in Activity.class if was inserted,
when this error is displayed.
List LinkedList Collections add sort find search Item, get searched item to string in Java example.
MainClass.java
MainClass.java
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
public class MainClass {
public static void main(String[] arg) {
String[] arrayOfString = {"nothing", "Hello", "people"
, "bye-bye", "hello", "world!", "End" };
List<String> arrayList = new LinkedList<String>();
for(String s: arrayOfString)
arrayList.add(s);
Collections.sort(arrayList);
// foreach
for (String str: arrayList)
System.out.println(str);
Object objMin = Collections.min(arrayList);
System.out.println("Min is: " + objMin);
Object objMax = Collections.max(arrayList);
System.out.println("Max is: " + objMax);
int index = Collections.binarySearch(arrayList, "people");
System.out.println("Index of people is: " + index);
// print word on index 5
System.out.println("Index 5 is: " + arrayList.get(5));
String sItem = arrayList.get(5); // get item from index 5 to string
}
}
/*
End
Hello
bye-bye
hello
nothing
people
world!
Min is: End
Max is: world!
Index of people is: 5
Index 5 is: people
*/
Long press by finger on screen
From dialogue select Widgets
Select your widget
Put your widget on the screen
Video tutorial - to add home screen widgets - Android 2.1
From dialogue select Widgets
Select your widget
Put your widget on the screen
Video tutorial - to add home screen widgets - Android 2.1
Editace: 2012-12-27 15:30:36
Počet článků v kategorii: 396
Url:asynctask-example-android-with-progressbar