我从互联网上获得了源代码,我尝试对其进行修改,以便它可以检索存储在 sd 卡中的文件夹之一中的所有图标并将其显示在 gridview 中。
同时,一旦用户单击该图标,它将链接到另一个活动。但我做不到。代码如下所示。
提前感谢那些可以提供帮助的人。
数据库处理程序.java
import java.util.ArrayList;
import java.util.List;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DataBaseHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "DISPLAYAPPS_MAIN";
// Contacts table name
private static final String TABLE_MAINAPPS = "MAINAPPS";
// Contacts Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_IMAGE = "image";
public DataBaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_APPS_TABLE = "CREATE TABLE " + TABLE_MAINAPPS + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
+ KEY_IMAGE + " BLOB" + ")";
db.execSQL(CREATE_APPS_TABLE);
}
// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_MAINAPPS);
// Create tables again
onCreate(db);
}
// Adding new apps
public void addApps(APPS apps) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, apps._name); // Apps Name
values.put(KEY_IMAGE, apps._image); // Apps image
// Inserting Row
db.insert(TABLE_MAINAPPS, null, values);
db.close(); // Closing database connection
}
// Getting single contact
APPS getAPPS(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_MAINAPPS, new String[] { KEY_ID,
KEY_NAME, KEY_IMAGE }, KEY_ID + "=?",
new String[] { String.valueOf(id) }, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
APPS apps = new APPS(Integer.parseInt(cursor.getString(0)),
cursor.getString(1), cursor.getBlob(1));
// return contact
return apps;
}
// Getting All Contacts
public List<APPS> getAllAPPS() {
List<APPS> appsList = new ArrayList<APPS>();
// Select All Query
String selectQuery = "SELECT * FROM MAINAPPS ORDER BY name";
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
APPS apps = new APPS();
apps.setID(Integer.parseInt(cursor.getString(0)));
apps.setName(cursor.getString(1));
apps.setImage(cursor.getBlob(2));
// String name = cursor.getString(1) +"\n"+ cursor.getBlob(2);
// Adding contact to list
appsList.add(apps);
} while (cursor.moveToNext());
}
// close inserting data from database
db.close();
// return contact list
return appsList;
}
// Updating single contact
public int updateAPPS(APPS apps) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, apps.getName());
values.put(KEY_IMAGE, apps.getImage());
// updating row
return db.update(TABLE_MAINAPPS, values, KEY_ID + " = ?",
new String[] { String.valueOf(apps.getID()) });
}
// Deleting single contact
public void deleteContact(APPS contact) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_MAINAPPS, KEY_ID + " = ?",
new String[] { String.valueOf(contact.getID()) });
db.close();
}
// Getting contacts Count
public int getContactsCount() {
String countQuery = "SELECT * FROM " + TABLE_MAINAPPS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
cursor.close();
// return count
return cursor.getCount();
}
GridviewAvtivity.java
import com.mkyong.android.adapter.ImageAdapter;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.TextView;
import android.widget.Toast;
import android.view.View;
import android.widget.AdapterView.OnItemClickListener;
public class GridViewActivity extends Activity {
GridView gridView;
static final String[] MOBILE_OS = new String[] { "Android", "Ios",
"Windows", "Blackberry" };
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
gridView = (GridView) findViewById(R.id.gridView1);
gridView.setAdapter(new ImageAdapter(this, MOBILE_OS));
gridView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
String label = ((TextView) arg1.findViewById(R.id.grid_item_label)).getText().toString();
if (label.equals("Android")) {
Intent AndroidActivity = new Intent(GridViewActivity.this,
AndroidActivity.class);
startActivity(AndroidActivity);
} else if (label.equals("Ios")) {
Intent IosActivity = new Intent(GridViewActivity.this,
IosActivity.class);
startActivity(IosActivity);
} else if (label.equals("Windows")) {
Intent WindowsActivity = new Intent(GridViewActivity.this,
WindowsActivity.class);
startActivity(WindowsActivity);
} else if (label.equals("Blackberry")) {
Intent BlackberryActivity = new Intent(GridViewActivity.this,
BlackberryActivity.class);
startActivity(BlackberryActivity);
}
}
});
}
}
ImageAdapter.java
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class ImageAdapter extends BaseAdapter {
private Context context;
private final String[] mobileValues;
public ImageAdapter(Context context, String[] mobileValues) {
this.context = context;
this.mobileValues = mobileValues;
}
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View gridView;
if (convertView == null) {
gridView = new View(context);
// get layout from mobile.xml
gridView = inflater.inflate(R.layout.mobile, null);
// set value into textview
TextView textView = (TextView) gridView
.findViewById(R.id.grid_item_label);
textView.setText(mobileValues[position]);
// set image based on selected text
ImageView imageView = (ImageView) gridView
.findViewById(R.id.grid_item_image);
String mobile = mobileValues[position];
if (mobile.equals("Windows")) {
imageView.setImageResource(R.drawable.windows_logo);
} else if (mobile.equals("iOS")) {
imageView.setImageResource(R.drawable.ios_logo);
} else if (mobile.equals("Blackberry")) {
imageView.setImageResource(R.drawable.blackberry_logo);
} else {
imageView.setImageResource(R.drawable.android_logo);
}
} else {
gridView = (View) convertView;
}
return gridView;
}
@Override
public int getCount() {
return mobileValues.length;
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
}