android gallery 图片轮播 展示SD卡下指定目录的图片 可删除

package mu.demo.m; import java.io.File; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.app.AlertDialog; import android.app.AlertDialog.Builder; import android.os.Bundle; import android.content.Context; import android.content.DialogInterface; import android.content.DialogInterface.OnClickListener; import android.content.res.TypedArray; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.AdapterView.OnItemLongClickListener; import android.widget.BaseAdapter; import android.widget.Gallery; import android.widget.ImageView; import android.widget.Toast; public class MainActivity extends Activity { /** Called when the activity is first created. */ List<String> it=new ArrayList<String>(); String s; Gallery g; ImageAdapter adapter; int position1; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); g=(Gallery)findViewById(R.id.gallery); it=getSD(); adapter=new ImageAdapter(this,it); g.setAdapter(adapter);//设置图片的适配器，并传递一个图片路径的字符串 g.setOnItemClickListener(new OnItemClickListener(){ //监听每一张图片 @Override public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) { // TODO Auto-generated method stub } }); g.setOnItemLongClickListener(new OnItemLongClickListener() { @Override public boolean onItemLongClick(AdapterView<?> adapter, View v, int position, long rowid) { s= it.get(position).toString(); position1=position; dialog(); return false; } }); } private List<String> getSD(){ File f=new File("/sdcard/Pictures/Screenshots/"); File[] files=f.listFiles(); System.out.println("-------------------"+files); for(int i=0;i<files.length;i++){ File file=files[i]; if(getImageFile(file.getPath())) it.add(file.getPath()); } return it; } private boolean getImageFile(String fName){ boolean re; String end=fName.substring(fName.lastIndexOf(".")+1,fName.length()).toLowerCase(); if(end.equals("jpg")|| end.equals("gif")|| end.equals("png")|| end.equals("jpeg")|| end.equals("bmp")) { re=true; }else{ re=false; } return re; } public class ImageAdapter extends BaseAdapter{ int mGalleryItemBackground; private Context mContext; private List<String> lis; public ImageAdapter(Context c,List<String> li){ mContext=c; lis=li; TypedArray a=obtainStyledAttributes(R.styleable.Gallery); mGalleryItemBackground=a.getResourceId(R.styleable.Gallery_android_galleryItemBackground, 0); a.recycle(); } @Override public int getCount() { // TODO Auto-generated method stub return lis.size(); } @Override public Object getItem(int arg0) { // TODO Auto-generated method stub return arg0; } @Override public long getItemId(int arg0) { // TODO Auto-generated method stub return arg0; } @Override public View getView(int position, View converView, ViewGroup parent) { // TODO Auto-generated method stub ImageView i=new ImageView(mContext); Bitmap bm=BitmapFactory.decodeFile(lis.get(position).toString()); i.setImageBitmap(bm); i.setScaleType(ImageView.ScaleType.FIT_XY); i.setLayoutParams(new Gallery.LayoutParams(520,360)); i.setBackgroundResource(mGalleryItemBackground); return i; } } public void deleteFile(File file) { if (file.delete()) { Toast.makeText(MainActivity.this, "删除成功", Toast.LENGTH_LONG).show(); adapter.lis.remove(position1); adapter.notifyDataSetChanged(); } else { Toast.makeText(MainActivity.this, "删除失败", Toast.LENGTH_LONG).show(); } } private void dialog() { AlertDialog.Builder builder = new Builder(MainActivity.this); builder.setMessage("确认删除么吗？"); builder.setTitle("提示"); builder.setPositiveButton("确认", new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); File f=new File(s); deleteFile(f); } }); builder.setNegativeButton("取消", new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }); builder.show(); } }