我想制作一个应用程序,它在网格视图中显示文档、pdf、txt 等文本文件,就像 ImageView 显示图像一样。在 android 中是否有这些文件的视图。代码如下,我可以在网格中查看图像,但不能查看文档文件。
public class MainActivity extends Activity implements OnItemClickListener{
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(70, 70));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(3, 3, 3, 3);
} else {
imageView = (ImageView) convertView;
}
Bitmap bm = decodeSampledBitmapFromUri(itemList.get(position), 100, 100);
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);
gridview.setOnItemClickListener(this);
String ExternalStorageDirectoryPath = Environment
.getExternalStorageDirectory()
.getAbsolutePath();
String targetPath = ExternalStorageDirectoryPath + "/img/";
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());
}
}
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
}
}