動態Spinner來變更Image

所需功能

1. 取得res/drawable資料夾下的所有檔案名稱
2. 由檔案名稱取得ResourceID
3. 點選並顯示圖檔

package java2.tw;

import java.lang.reflect.Field;

import java.util.ArrayList;

import java.util.List;

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.widget.AdapterView;

import android.widget.ArrayAdapter;

import android.widget.ImageView;

import android.widget.Spinner;

import android.widget.Toast;

import android.widget.AdapterView.OnItemSelectedListener;

public class mySpinner extends Activity {

private Spinner mySpinner;

private ImageView myImageView;

private ArrayAdapter myArrayAdapter;

static String[] myResource;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

mySpinner = (Spinner) findViewById(R.id.mySpinner);

myImageView = (ImageView) findViewById(R.id.myImageView);

getResourceName();

myArrayAdapter = new ArrayAdapter(this,

android.R.layout.simple_spinner_item, myResource);

mySpinner.setAdapter(myArrayAdapter);

mySpinner.setOnItemSelectedListener(new OnItemSelectedListener() {

@Override

public void onItemSelected(AdapterView arg0, View arg1,

int arg2, long arg3) {

myImageView.setImageResource(getResourceIDByName(

R.drawable.class, myResource[arg2]));

}

@Override

public void onNothingSelected(AdapterView arg0) {

}

});

}

private void getResourceName() {

String[] resource;

List list = new ArrayList();

for (Field f : R.drawable.class.getDeclaredFields()) {

try {

list.add(f.getName());

} catch (Exception e) {

Toast.makeText(this, "圖片目錄載入失敗", Toast.LENGTH_SHORT).show();

}

}

resource = new String[list.size()];

for (int i = 0; i <>

resource[i] = list.get(i);

}

myResource = resource;

}

private int getResourceIDByName(Class aClass, String resourceName) {

Field[] drawableFields = aClass.getFields();

int resourceID = 0;

for (Field f : drawableFields) {

if (resourceName.equals(f.getName())) {

try {

resourceID = f.getInt(null);

} catch (IllegalArgumentException e) {

e.printStackTrace();

} catch (IllegalAccessException e) {

e.printStackTrace();

}

}

}

return resourceID;

}

}