Home › Uncategorized

GridView loading photos from SD Card

Previous exercises described how to implement "Gallery-like HorizontalScrollView" and "Vertical Gallery-like ScrollView". Alternatively, it can be displayed in GridView.

Add a <GridView> in layout.

<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"> <GridView android:id="@+id/gridview" android:layout_width="fill_parent" android:layout_height="fill_parent" android:columnWidth="90dp" android:numColumns="auto_fit" android:verticalSpacing="10dp" android:horizontalSpacing="10dp" android:stretchMode="columnWidth" android:gravity="center"/> </LinearLayout>

Main code:

package com.example.androidgridview; import java.io.File; import java.util.ArrayList; import android.os.Bundle; import android.os.Environment; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.GridView; import android.widget.ImageView; import android.widget.Toast; public class MainActivity extends Activity { public class ImageAdapter extends BaseAdapter { private Context mContext; ArrayList<String> itemList = new ArrayList<String>(); public ImageAdapter(Context c) { mContext = c; } void add(String path){ itemList.add(path); } @Override public int getCount() { return itemList.size(); } @Override public Object getItem(int arg0) { // TODO Auto-generated method stub return null; } @Override public long getItemId(int position) { // TODO Auto-generated method stub return 0; } @Override public View getView(int position, View convertView, ViewGroup parent) { ImageView imageView; if (convertView == null) { // if it's not recycled, initialize some attributes imageView = new ImageView(mContext); imageView.setLayoutParams(new GridView.LayoutParams(220, 220)); imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); imageView.setPadding(8, 8, 8, 8); } else { imageView = (ImageView) convertView; } Bitmap bm = decodeSampledBitmapFromUri(itemList.get(position), 220, 220); imageView.setImageBitmap(bm); return imageView; } public Bitmap decodeSampledBitmapFromUri(String path, int reqWidth, int reqHeight) { Bitmap bm = null; // First decode with inJustDecodeBounds=true to check dimensions final BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; BitmapFactory.decodeFile(path, options); // Calculate inSampleSize options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight); // Decode bitmap with inSampleSize set options.inJustDecodeBounds = false; bm = BitmapFactory.decodeFile(path, options); return bm; } public int calculateInSampleSize( BitmapFactory.Options options, int reqWidth, int reqHeight) { // Raw height and width of image final int height = options.outHeight; final int width = options.outWidth; int inSampleSize = 1; if (height > reqHeight || width > reqWidth) { if (width > height) { inSampleSize = Math.round((float)height / (float)reqHeight); } else { inSampleSize = Math.round((float)width / (float)reqWidth); } } return inSampleSize; } } ImageAdapter myImageAdapter; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); GridView gridview = (GridView) findViewById(R.id.gridview); myImageAdapter = new ImageAdapter(this); gridview.setAdapter(myImageAdapter); String ExternalStorageDirectoryPath = Environment .getExternalStorageDirectory() .getAbsolutePath(); String targetPath = ExternalStorageDirectoryPath + "/test/"; Toast.makeText(getApplicationContext(), targetPath, Toast.LENGTH_LONG).show(); File targetDirector = new File(targetPath); File[] files = targetDirector.listFiles(); for (File file : files){ myImageAdapter.add(file.getAbsolutePath()); } } }