Android：更改ImageView源使我的应用程序意外关闭

Question

I just signed up in order to ask for help. I'm doing an application which displays an image gallery. When you click any of the images, it must open the image and show it.

There are two activities: 'Galeria' and 'Imagen'. 'Galeria' displays the image gallery and 'Imagen' displays the image clicked. When an image is clicked, I create the second activity using an Intent as seen in the code below.

Galeria.java code:

package com.ejemplo.galeria;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.View;

public class Galeria extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

    //Called when an image is clicked (I use ImageButtons)
    public void openImage(View view){
        Intent i = new Intent(this,Imagen.class);
        i.putExtra("IMAGEN", view.getId());
        startActivity(i);
    }
}

The method 'openImage()' is called when any of the ImageButton is pushed (Whatever button you press, the same method is called). Here is the 'main.xml' code:

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".Galeria" >

<HorizontalScrollView
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"
    android:id = "@+id/scrollview">
    <LinearLayout
        android:id="@+id/layout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <ImageButton
            android:id="@+id/imagen1"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:scaleType="fitXY"
            android:onClick="openImage"
            android:src="@drawable/imagen1"></ImageButton>
        <ImageButton
            android:id="@+id/imagen2"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:scaleType="fitXY"
            android:onClick="openImage"
            android:src="@drawable/imagen2"></ImageButton>
        <ImageButton
            android:id="@+id/imagen3"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:scaleType="fitXY"
            android:onClick="openImage"
            android:src="@drawable/imagen3"></ImageButton>
        <ImageButton
            android:id="@+id/imagen4"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:scaleType="fitXY"
            android:onClick="openImage"
            android:src="@drawable/imagen4"></ImageButton>
        <ImageButton
            android:id="@+id/imagen5"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:scaleType="fitXY"
            android:onClick="openImage"
            android:src="@drawable/imagen5"></ImageButton>
        <ImageButton
            android:id="@+id/imagen6"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:scaleType="fitXY"
            android:onClick="openImage"
            android:src="@drawable/petergriffin"></ImageButton>
         <ImageButton
            android:id="@+id/imagen7"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:scaleType="fitXY"
            android:onClick="openImage"
            android:src="@drawable/gato"></ImageButton>
    </LinearLayout>
</HorizontalScrollView>

</RelativeLayout>

So, this is the code of the 'Image' class:

package com.ejemplo.galeria;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.ImageView;

public class Imagen extends Activity{

    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        Intent i = getIntent();
        int id = i.getIntExtra("IMAGEN", -1);
        if(id != -1){
            ImageView iv = (ImageView) findViewById(R.id.imageV1);
            iv.setImageResource(id); //Error
            setContentView(R.layout.imagen);
        }
    }
}

And this is the XML code of 'imagen.xml' file:

<?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" >
    <ImageView
        android:id="@+id/imageV1"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content" ></ImageView>

</LinearLayout>

So, when I modify the source of the ImageView, my applications closes unexpectedly, and I have no idea why. I've been looking for help but I found nothing, so I wish anyone can help me, I'm getting mad.

Thank you!

------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------

OK I FOUND THE ISSUE

I changed the parameter in the method 'setImageResource(id)' for R.drawable.imagen1 and constructed the switch case statement.

But it kept closing unexpectedly!!!

So, in the method 'onCreate()' of 'Imagen' class, I just moved the line 'setContentView(R.layout.imagen)' from the end of the method to the beginning.

PROBLEM SOLVED :)

Answer 1

So here:

Intent i = new Intent(this,Imagen.class);
i.putExtra("IMAGEN", view.getId());
startActivity(i);

you just put view id in intent, but after:

int id = i.getIntExtra("IMAGEN", -1);
if(id != -1){
      ImageView iv = (ImageView) findViewById(R.id.imageV1);
      iv.setImageResource(id); //Error
      setContentView(R.layout.imagen);
}

you try assign this R.id to image resource, this is wrong, because setImageResource expecting something like R.drawable.my_image . Please follow javadoc .

Answer 2

 public void openImage(View view){
    Intent i = new Intent(this,Imagen.class);
    i.putExtra("IMAGEN", view.getId());
    startActivity(i);
}

The above view.getId() will return the id of the particular imagebutton. This is no way related to the drawable resource. So when you setImage() in the other activity it will indeed through a error as you are trying to set a button to a image view.

Instead you can construct a switch case statement to send the corresponding drawable id to the other activity.

Answer 3

As others said - you are trying to set View id as ImageResource - those are different two things; so to fix your problem I would suggest something like this

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.imagen); // before findViewById
    Intent i = getIntent();
    int id = i.getIntExtra("IMAGEN", -1);
    if(id != -1){
        ImageView iv = (ImageView) findViewById(R.id.imageV1);
        switch (id) {
         case R.id.imagen1: // first one
           iv.setImageResource(R.drawable.imagen1);
         break;
         // repeat for others
        } // switch close

    } // if 
} // onCreate

anyway it seems to me like you would benefit from using ListView / GridView together w/ some ArrayAdapter