Question

i’m a newbie of android 🙂

I want to create a simple slideshow with a numeric parameter(x) and a button.I have 21 images and, at the click of the button, I want to catch x and “slide” only the first x images of the list.Between one image and the next i want wait 1 second.

At the end i want to know how much time passed during the operation. (sorry for my english)

paste below the code of the activity and the layout:

package com.superpibenchmarknative;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;



public class ImageActivity extends Activity implements OnClickListener {
private Button start;
private EditText iteractions;
private TextView time;
private ImageView display;
private long after,before;
private int images[] = {R.drawable.image1,R.drawable.image2,R.drawable.image3,
                        R.drawable.image4,R.drawable.image5,R.drawable.image6,R.drawable.image7,
                        R.drawable.image8,R.drawable.image9,R.drawable.image10,R.drawable.image11,
                        R.drawable.image12,R.drawable.image13,R.drawable.image14,R.drawable.image15,
                        R.drawable.image16,R.drawable.image17,R.drawable.image18,R.drawable.image19,
                        R.drawable.image20,R.drawable.image21,
        };
@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_image);
    setUpUI();
}

private void setUpUI() {
    // TODO Auto-generated method stub
    start = (Button) findViewById(R.id.bntStartCalcolation);
    iteractions = (EditText) findViewById(R.id.etIterations);
    time = (TextView) findViewById(R.id.tvTime);

    start.setOnClickListener(this);
}

@Override
public void onClick(View arg0) {
    //Creo le imageview in base al # di iteractions 
    before = System.currentTimeMillis();
    for (int j = 0; j < Integer.parseInt(iteractions.getText().toString());j++){
        display = (ImageView) findViewById(R.id.ivDisplay);
        display.setImageResource(images[j]);
        Handler handler = new Handler(); 
        handler.postDelayed(new Runnable() { 
             public void run() { 
                  display = null;
                  System.gc();
             } 
        }, 1000); 

    }
    display = null;
    System.gc();
    after = System.currentTimeMillis();
    time.setText(String.valueOf(after-before-1000* Integer.parseInt(iteractions.getText().toString())));
}

}

and this is the layout:

<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"
tools:context=".ImageActivity" >

<TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="5dp"
    android:layout_marginLeft="15dp"
    android:layout_marginRight="15dp"
    android:layout_marginTop="10dp"
    android:padding="5dp"
    android:text="Benchmark del rendering di immagini" />

<EditText
    android:id="@+id/etIterations"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginBottom="5dp"
    android:layout_marginLeft="15dp"
    android:layout_marginRight="15dp"
    android:layout_marginTop="5dp"
    android:hint="# di iterazioni"
    android:inputType="number"
    android:padding="5dp" />

<Button
    android:id="@+id/bntStartCalcolation"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginBottom="5dp"
    android:layout_marginLeft="15dp"
    android:layout_marginRight="5dp"
    android:layout_marginTop="5dp"
    android:text="Start Calcolation" />

<ImageView  android:id="@+id/ivDisplay"
            android:layout_width="200dp"
            android:layout_height="200dp"
            android:layout_gravity="center"/>

<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:weightSum="100" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="15dp"
        android:layout_weight="50"
        android:text="Risultato ottenuto in: " />

    <TextView
        android:id="@+id/tvTime"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="15dp"
        android:layout_weight="50" />
</LinearLayout>

this code dosn’t work, it create an exception

OutOfMemoryError: bitmap size exceed the vm budget

anyone can help me to solve this problem?? 🙂 thanks at all however 😀

great all works 😀 but i’ve a little more questions

I don’t understand why the time is always negative!!!
anyone of you know why?? [postDelayed not works?!? 🙁 ]

solved with: android.os.SystemClock.sleep(1000);

Another error, the ImageView dosn’t change after the setting of an image, any suggestions??

Answer 1

There is a small guide within the developer site regarding loading large bitmap files. The idea is to load lower resolution files so that they should fit in memory: http://developer.android.com/training/displaying-bitmaps/load-bitmap.html