Android-从res / drawable onClick显示图像

Question

First of all, I wanna say I've been seeking for an answer on the Forum and I found didn't match for what I wanted. Basically, what I want is: when the user clicks on one of the images previously "specified" on the .xml file, a new image is displayed on the center of the screen that is not "specified" on the .xml file. I wrote "specified" cause idk if it's the correct way to refer to this.

EDIT: there was no need to not specify the image previously, all I needed was to set "gone" for visibiity. This code is working exactly how I wanted (ty guys):

Main.java

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageView;
import android.widget.Toast;

public class Principal extends Activity {
    ImageView cuia1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_principal);
        cuia1 = (ImageView) findViewById(R.id.cuia1);
        cuia1.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                ImageView cuia1grande = (ImageView) findViewById(R.id.cuia1grande);
                cuia1grande.setVisibility(1);
            }
        });

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.principal, menu);
        return true;
    }
}

activity.xml

    <?xml version="1.0" encoding="utf-8"?>  
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"  
android:id="@+id/relativeLayout1"  
android:layout_width="match_parent"  
android:layout_height="match_parent">  

<TableLayout
    android:id="@+id/tableLayout1"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    android:shrinkColumns="*"  
    android:stretchColumns="*">   

    <TableRow   
        android:id="@+id/tabelaCuias"  
        android:layout_height="wrap_content"  
        android:layout_width="match_parent"  
        android:gravity="center">    

        <TextView  
            android:id="@+id/selecionaCuia"  
            android:text="Selecione a cuia"  
            android:textStyle="bold">            
        </TextView>  

        <ImageView  
            android:id="@+id/cuia1"  
            android:src="@drawable/cuia1">            
        </ImageView>  

        <ImageView  
            android:id="@+id/cuia2"  
            android:src="@drawable/cuia2">            
        </ImageView>  

        <ImageView  
            android:id="@+id/cuia3"  
            android:src="@drawable/cuia3">            
        </ImageView>  

        <ImageView  
            android:id="@+id/cuia4"  
            android:src="@drawable/cuia4">            
        </ImageView>                         
    </TableRow>  
</TableLayout>

<ImageView  
    android:layout_height="wrap_content"  
    android:layout_width="match_parent"
    android:layout_centerInParent="true"
    android:visibility="gone"
    android:id="@+id/cuia1grande"  
    android:src="@drawable/cuia1grande">            
</ImageView>

Answer 1

Is there any reason you don't want to "specify" the image in your layout file? You could place it there and not display it ( visibilty="gone" ), and then show/hide it when you deem fit.

Here's what I'd do:

1. Make your layout a RelativeLayout instead of a TableLayout (this will make things easier for showing the image in the center)

2. Place your TableLayout within the wrapping RelativeLayout

3. Define an ImageView as the last child within the wrapping RelativeLayout , set centerInParent="true" , visibilty="gone"

4. In your onClick method, simply set its visibility as visible .

If you really don't want to define the ImageView in the layout, then you can create it programmatically:

1. Follow the same steps 1-2 as before

2. Capture the reference to the wrapping RelativeLayout in the code

3. In the onClick method, create the ImageView programatically, specifying the centerInParent="true" via the code (let me know if you want an example on how to do this & I'll edit the answer with a code sample).

4. Add the new view to the RelativeLayout via myRelativeLayout.addView(myImageView);

Hope this helps :)

Answer 2

public class Principal extends Activity {
    ImageView cuia1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_principal);
        cuia1 = (ImageView) findViewById(R.id.cuia1);
        //set invisible
        cuia1 .setVisibility(View.INVISIBLE);
        cuia1.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                //show image on the center of screen  
                //set image
                cuia1.setImageResource(R.drawable.cuia1);
                // set visible
                cuia1 .setVisibility(View.VISIBLE);
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {     
        getMenuInflater().inflate(R.menu.principal, menu);
        return true;
    }
}

import import android.view.View;

Cheerz!