I am trying to implement a slideshow in my android app. I have an imageview and a text view in my xml file. I want that imageview to show a slideshow of some images. The images are stored in drawable-hdpi. When I am opening this page, only text view is showing up and not the slideshow. Not a single image is showing.
Following is the java file for the same.
package abc.xys;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.ImageView;
import android.widget.TextView;
public class Wishes extends Activity {
ImageView slide;
TextView msg;
int i=0;
int imgid[]={R.drawable.friends01,R.drawable.friends02,R.drawable.friends03,R.drawable.friends04,R.drawable.friends05};
RefreshHandler refreshHandler=new RefreshHandler();
#SuppressLint("HandlerLeak")
class RefreshHandler extends Handler{
#Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
Wishes.this.updateUI();
}
public void sleep(long delayMillis){
this.removeMessages(0);
sendMessageDelayed(obtainMessage(0), delayMillis);
}
};
public void updateUI(){
int currentInt=Integer.parseInt((String)msg.getText())+10;
if(currentInt<=100){
refreshHandler.sleep(2000);
msg.setText(String.valueOf(currentInt));
if(i<imgid.length){
slide.setImageResource(imgid[i]);
// slide.setPadding(left, top, right, bottom);
i++;
}
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.wishes_template);
slide = (ImageView) findViewById(R.id.slideshow);
msg = (TextView) findViewById(R.id.message);
}
}
The xml file (wishes_template) is:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="#+id/slideshow_layout"
>
<ImageView android:id="#+id/slideshow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:paddingTop="20dp"
></ImageView>
<TextView android:text="10"
android:id="#+id/message"
android:layout_width="fill_parent"
android:layout_height="wrap_content"></TextView>
</LinearLayout>
Thanks in advance!
Related
i have a few pages realized with a PagerAdapter and one layout-file in the folder "res/layout" and one layout-file in "res/layout-land". Each Layout has two ImageButtons, where:
imageButton1 in portrait has the same ID as the imageButton1 in landscape.
imageButton2 in portrait has the same ID as the imageButton2 in landscape.
I have assigned an onClickListener to imageButton1 button which:
takes the images from the ImageButtons
rescales the Images to fit/fill the ImageButtons
and reassigns the rescaled pictures to the ImageButtons.
But whenever i change the orientation in my emulator the images/pictures in these buttons get lost, or change to the images specified in the layout-file originally and dont refresh to the pictures i assigned to the buttons programmatically.
PS (for example): i assigned in onCreate a listener to button1 and that listener works for this button both in portrait and also in landscape. So these are not seperated buttons!!!!!!
Question: how can i make it work that the images are not lost when changing orientation?
thx for any help in advance!
here is my code:
layout-portrait file:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:id="#+id/table1"
android:background="#drawable/shape"
android:gravity="center"
>
<!-- Row 1-->
<LinearLayout
android:layout_width="fill_parent"
android:orientation="horizontal"
android:layout_height="fill_parent"
android:layout_weight="1"
android:gravity="center">
<LinearLayout
android:id="#+id/layout11"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#drawable/shape" >
<ImageButton
android:id="#+id/imageButton1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="#drawable/ic_launcher" />
</LinearLayout>
<LinearLayout
android:id="#+id/layout12"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#drawable/shape" >
<ImageButton
android:id="#+id/imageButton2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="#drawable/ic_launcher" />
</LinearLayout>
</LinearLayout>
layout-landscape file:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:id="#+id/table1"
android:background="#drawable/shape"
android:gravity="center"
>
<LinearLayout
android:layout_width="fill_parent"
android:orientation="horizontal"
android:layout_height="fill_parent"
android:layout_weight="1"
android:gravity="center">
<LinearLayout
android:id="#+id/layout11"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#drawable/shape" >
<ImageButton
android:id="#+id/imageButton1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="#drawable/ic_launcher" />
</LinearLayout>
<LinearLayout
android:id="#+id/layout12"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#drawable/shape" >
<ImageButton
android:id="#+id/imageButton2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="#drawable/ic_launcher" />
</LinearLayout>
</LinearLayout>
MyPageAdapter-class:
package com.example.Pagercheck;
import java.util.List;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
public class MyPageAdapter extends PagerAdapter
{
List<View> pages = null;
public MyPageAdapter(List<View> pages)
{
this.pages = pages;
}
#Override
public int getCount()
{
return pages.size();
}
#Override
public boolean isViewFromObject(View view, Object object)
{
return view.equals(object);
}
#Override
public Object instantiateItem(View collection, int position)
{
View v = pages.get(position);
((ViewPager) collection).addView(v, 0);
return v;
}
#Override
public void destroyItem(View collection, int position, Object view)
{
((ViewPager) collection).removeView((View) view);
}
#Override
public void finishUpdate(View arg0) {
}
#Override
public void startUpdate(View arg0) {
}
}
My MainActivity-Class:
package com.example.Pagercheck;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.res.Configuration;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.SimpleOnPageChangeListener;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.ViewGroup.MarginLayoutParams;
import android.view.ViewTreeObserver;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.GridView;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener
{
private List<View> pages;
private MyPageAdapter pagerAdapter;
private ViewPager viewPager;
private static Context context; //member zum speichern für context für andere Klassen
public static Context getContext(){ return context;} //context für andere Klassen zugänglich machen
//private Button btn1;
#Override
protected void onCreate(Bundle savedInstanceState)
{
context = this; //context in member speichern
LayoutInflater inflater = LayoutInflater.from(this);
pages = new ArrayList<View>();
View page = inflater.inflate(R.layout.page, null);
pages.add(page);
page = inflater.inflate(R.layout.page, null);
pages.add(page);
page = inflater.inflate(R.layout.page, null);
pages.add(page);
page = inflater.inflate(R.layout.page, null);
pages.add(page);
page = inflater.inflate(R.layout.page, null);
pages.add(page);
pagerAdapter = new MyPageAdapter(pages);
viewPager = new ViewPager(this);
viewPager.setAdapter(pagerAdapter);
viewPager.setCurrentItem(0);
setContentView(viewPager);
for (int i_page=0;i_page<pages.size();i_page++)
{
//Drag-Listener auf ImageButtons:
pages.get(i_page).findViewById(R.id.imageButton1).setOnLongClickListener(new MyLongClickListener());
pages.get(i_page).findViewById(R.id.imageButton1).setOnClickListener(this);
pages.get(i_page).findViewById(R.id.imageButton2).setOnLongClickListener(new MyLongClickListener());
//Drag-Listener auf LinearLayouts:
pages.get(i_page).findViewById(R.id.layout11).setOnDragListener(new MyDragListener());
pages.get(i_page).findViewById(R.id.layout12).setOnDragListener(new MyDragListener());
}
super.onCreate(savedInstanceState);
}
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public void onWindowFocusChanged(boolean hasFocus)
{
// TODO Auto-generated method stub
super.onWindowFocusChanged(hasFocus);
//NOTE FOR STACKOVERFLOW
//I COMMENTED THIS OUT SO THAT MY IMAGE BUTTONS DOESNT GET LOST AFTER PAGE 2 SO THAT I CAN TEST MY APP PROPERLY WITH ONCLICK:
// Bitmap bmp_stift=BitmapFactory.decodeResource(getContext().getResources(), R.drawable.stift);
//
// for (int i_page=0;i_page<pages.size();i_page++)
// {
//
// ((ImageButton)pages.get(i_page).findViewById(R.id.imageButton1)).setImageBitmap(bmp_stift);
// scalePictureToFitButtom((ImageButton)pages.get(i_page).findViewById(R.id.imageButton1));
// scalePictureToFitButtom((ImageButton)pages.get(i_page).findViewById(R.id.imageButton2));
//
//
// }
}
public void scalePictureToFitButtom(ImageButton img_btn)
{
int width=img_btn.getWidth();
int height=img_btn.getHeight();
BitmapDrawable draw=(BitmapDrawable)img_btn.getDrawable();
Bitmap bmp = ((BitmapDrawable)draw).getBitmap();
Bitmap resized = Bitmap.createScaledBitmap(bmp, width-40, height-40, true); //bissle schmaler und niedriger damit man noch den Klickeffekt sieht
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
params.width=width;
params.height=height;
img_btn.setImageBitmap(resized);
img_btn.setLayoutParams(params);
pagerAdapter.notifyDataSetChanged();
}
#Override
public void onClick(View view)
{
Bitmap bmp_stift=BitmapFactory.decodeResource(getContext().getResources(), R.drawable.stift);
for (int i_page=0;i_page<pages.size();i_page++)
{
((ImageButton)pages.get(i_page).findViewById(R.id.imageButton1)).setImageBitmap(bmp_stift);
scalePictureToFitButtom((ImageButton)pages.get(i_page).findViewById(R.id.imageButton1));
scalePictureToFitButtom((ImageButton)pages.get(i_page).findViewById(R.id.imageButton2));
}
Toast einToast = Toast.makeText(view.getContext(), "clicked", Toast.LENGTH_SHORT);
einToast.show();
}
}
UPDATE:
i did it like this now (example for saving and restoring Bitmap of imageButton1):
#Override
protected void onSaveInstanceState(Bundle outState)
{
// TODO Auto-generated method stub
super.onSaveInstanceState(outState);
BitmapDrawable draw=(BitmapDrawable)((ImageButton)pages.get(0).findViewById(R.id.imageButton1)).getDrawable();
Bitmap bmp = ((BitmapDrawable)draw).getBitmap();
outState.putParcelable("IMG_OF_BUTTON1", bmp);
super.onSaveInstanceState(outState);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState)
{
// TODO Auto-generated method stub
super.onRestoreInstanceState(savedInstanceState);
Bitmap bmp= savedInstanceState.getParcelable("IMG_OF_BUTTON1");
((ImageButton)pages.get(0).findViewById(R.id.imageButton1)).setImageBitmap(bmp);
}
I just wanted to click on a button to see a text. Do I Need to import the public boolean onCreateOptionsMenu(Menu menu)? Or what am I doing wrong? I tried to Import some things, but it didn't help. Java-Code:
package com.example.tsd453;
import android.app.Activity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class Blume extends Activity implements OnClickListener {
public Button btn;
public TextView tw;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.blume);
btn = (Button)findViewById(R.id.BtnKlick);
tw = (TextView)findViewById(R.id.Text);
btn.setOnClickListener(this);
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
tw.setText("Hallo");
XML:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="#+id/Text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginRight="70dp"
android:layout_marginTop="50dp"
android:textSize="70sp" />
<Button
android:id="#+id/BtnKlick"
android:layout_width="100dp"
android:layout_height="70dp"
android:layout_centerInParent="true"
android:layout_marginTop="31dp"
android:text="Button" />
</RelativeLayout>
you could try this:
instead of
btn.setOnClickListener(this);
and
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
tw.setText("Hallo");
try this in your onCreate:
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
tw.setText("Hallo, Welt!");
}
});
and you don't need to "implements onClickListener" in class blume
and e.g. use android:layout_below="#id/tw" in the xml file of the button to set the button below the textview
EDIT:
i just tried it on my nexus 5, and this code (i think it is the same like yours) is working
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity implements OnClickListener {
public Button btn;
public TextView tw;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn = (Button)findViewById(R.id.BtnKlick);
tw = (TextView)findViewById(R.id.Text);
btn.setOnClickListener(this);
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
tw.setText("Hallo");
}
}
i removed the options menu, but it also worked with it.
screenshot:
https://copy.com/3TX47IAK9gya
screenshot of the code in android studio:
https://copy.com/hbwnH0vZkzMn
It seems that the Button is hiding the TextView, try setting margin like:
<TextView
android:layout_marginTop="50dp" />
<Button
android:layout_marginTop="150dp"
/>
and remove center align (at least for one of them).
I'm very new to Android development and just started to study.
What I'm trying is to add a button and when that button is pressed a text "my first project" to get displayed in the text view.
With the help of some experts I created the button and text view.
So the button is showing in the simulator but when I click that button nothing happens.
Can anyone please help me with how can I display the text when pressing the button?
.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/txtView"
android:layout_width="150dp"
android:layout_height="150dp"
android:text="#string/hello" />
<Button
android:id="#+id/mybtn"
android:layout_width="50dp"
android:layout_height="30dp" />
<TextView
android:id="#+id/viewwidth"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<TextView
android:id="#+id/viewheight"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</LinearLayout>
.java
import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.TextView;
import android.view.View;
import android.widget.Toast;
public class NameonbuttonclickActivity extends Activity implements View.OnClickListener {
Button mybtn;
TextView txtView;
String hello;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.main);
super.onCreate(savedInstanceState);
mybtn= new Button(this);
txtView=new TextView(this);
mybtn.setOnClickListener(this);
printmyname();
mybtn = (Button)findViewById(R.id.mybtn);
txtView=(TextView)findViewById(R.id.txtView);
txtView = (TextView)findViewById(R.id.viewwidth);
txtView = (TextView)findViewById(R.id.viewheight);
hello="This is my first project";
//setContentView(mybtn);
// setContentView(R.layout.main);
}
public void onClick(View view){
txtView.setText(hello);
//printmyname();
Toast.makeText(NameonbuttonclickActivity.this, hello, Toast.LENGTH_LONG).show();
}
private void printmyname(){
System.out.println("coming");
}
}
You can do like this:
String hello;
public void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.main);
super.onCreate(savedInstanceState);
mybtn = (Button)findViewById(R.id.mybtn);
txtView=(TextView)findViewById(R.id.txtView);
txtwidth = (TextView)findViewById(R.id.viewwidth);
hello="This is my first project";
mybtn.setOnClickListener(this);
}
public void onClick(View view){
txtView.setText(hello);
}
Check your textview names. Both are same . You must use different object names and you have mentioned that textview object which is not available in your xml layout file.
Hope this will help you.
First create xml file as follows. Create one textview and a button:
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello" />
<Button
android:id="#+id/mybutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Click Me" />
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
The first TextView is created by default. You can leave or remove it if you want.
Next one is to create a button
The next one is TextView where you want to display text.
Now coming to the main activity code...
package com.android.example.simple;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class SimpleActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final TextView textView=(TextView)findViewById(R.id.textView1);
final Button button1 = (Button)findViewById(R.id.mybutton);
//Implement listener for your button so that when you click the
//button, android will listen to it.
button1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Perform action on click
textView.setText("You clicked the button");
} });
}
}
This is because you DON'T associated the OnClickListener() on the button retrieve from the XML layout.
You don't need to create object because they are already created by the Android system when you inflate XML file (with the Activity.setContentLayout( int resourceLayoutId ) method).
Just retrieve them with the findViewById(...) method.
Just check your code in .java class
You had written below line
mybtn.setOnClickListener(this);
before initializing the mybtn object I mean
mybtn = (Button)findViewById(R.id.mybtn);
just switch this two line or put that line "mybtn.setOnClickListener(this)" after initializing your mybtn object and you will get the answer what you want..
Try this
public void onClick(View view){
txtView.setText("hello");
//printmyname();
Toast.makeText(NameonbuttonclickActivity.this, "hello", Toast.LENGTH_LONG).show();
}
Also in toast use "Hello"
you use this as txtView.setText("hello");
MainActivity.java:
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import android.view.View;
import android.view.View.OnClickListener;
public class MainActivity extends Activity {
Button button1;
TextView textView1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button1=(Button)findViewById(R.id.button1);
textView1=(TextView)findViewById(R.id.textView1);
button1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
textView1.setText("TextView displayed Successfully");
}
});
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Click here" />
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
public void onCreate(Bundle savedInstanceState)
{
setContentView(R.layout.main);
super.onCreate(savedInstanceState);
mybtn = (Button)findViewById(R.id.mybtn);
txtView=(TextView)findViewById(R.id.txtView);
mybtn .setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
txtView.SetText("Your Message");
}
});
}
Check this:
hello.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View paramView) {
text.setText("hello");
}
});
I have the following actvity.
package org.dewsworld.ui;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
public class DetailList extends Activity {
TextView title = (TextView) findViewById(R.id.title) ;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.detail_list);
title.setText("hello world");
}
}
Which manipulate detail_list.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent" android:weightSum="1">
<TextView android:id="#+id/title" android:textAppearance="?android:attr/textAppearanceMedium"
android:layout_height="wrap_content" android:layout_width="match_parent"
android:text="#string/headline" />
<ListView android:id="#+id/listView1" android:layout_width="match_parent" android:layout_height="match_parent"></ListView>
</LinearLayout>
But, when I run this, I get a runtime error. LogCat is,
try like this
public class DetailList extends Activity {
TextView title;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.detail_list);
title = (TextView) findViewById(R.id.title) ;
title.setText("hello world");
}
}
package org.dewsworld.ui;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
public class DetailList extends Activity {
TextView title;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.detail_list);
title = (TextView) findViewById(R.id.title) ;;
title.setText("hello world");
}
}
its complaining because you are trying to get the value of textView using an Activity method which is not been created yet (Since its Oncreate() is yet to run)
i have imageview and i have to display different image in
that with time interval, but when i change the ImageResource
the last image is displayed
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ImageView image = (ImageView) findViewById(R.id.test_image);
image.setImageResource(R.drawable.test);
try {
Thread.sleep(2000) ;
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
image = (ImageView) findViewById(R.id.test_image);
image.setImageResource(R.drawable.test2);
}
Kindly Suggest the Right way to do that
Thanks in Advance
Perhaps this thread is what you are looking for:
how to change images with timer
Whenever you want to update the user interface without performing any action or event, handlers should be used.
This is the sample code
Main.java
package com.balaji.handler;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.ImageView;
import android.widget.TextView;
public class Main extends Activity {
private ImageView txtStatus;
int i=0;
int imgid[]={R.drawable.icon,R.drawable.back,R.drawable.slider,R.drawable.forward};
private RefreshHandler mRedrawHandler = new RefreshHandler();
class RefreshHandler extends Handler {
#Override
public void handleMessage(Message msg) {
Main.this.updateUI();
}
public void sleep(long delayMillis) {
this.removeMessages(0);
sendMessageDelayed(obtainMessage(0), delayMillis);
}
};
private void updateUI(){
//int currentInt = Integer.parseInt((String) txtStatus.getText()) + 10;
if(i<imgid.length){
mRedrawHandler.sleep(1000);
txtStatus.setBackgroundResource(imgid[i]);
i++;
}
}
#Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
this.txtStatus = (ImageView)this.findViewById(R.id.txtStatus);
updateUI();
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageView
android:id="#+id/txtStatus"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true">
</ImageView>
</RelativeLayout>