我制作了一款可让用户添加学校科目的应用。 在我继续之前,让我告诉你我的代码:
MainActivity:
package cannon.gaming.mymarks;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.text.Html;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class MainActivity extends ActionBarActivity {
TextView textSubject;
String SUBJECT, PASS;
Context ctx = this;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().hide();
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
/*Button buttonAdd = (Button) findViewById(R.id.buttonAdd);
buttonAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(v.getContext(), RegisterActivity.class);
intent.setFlags(intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.putExtra("EXIT", true);
startActivityForResult(intent, 0);
}
});*/
Button buttonAdd = (Button) findViewById(R.id.buttonAdd);
textSubject = (TextView) findViewById(R.id.textSubject);
buttonAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
showInputDialog();
}
});
}
protected void showInputDialog() {
// get prompts.xml view
LayoutInflater layoutInflater = LayoutInflater.from(MainActivity.this);
View promptView = layoutInflater.inflate(R.layout.activity_dialog, null);
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(MainActivity.this);
alertDialogBuilder.setView(promptView);
final EditText editText = (EditText) promptView.findViewById(R.id.edittext);
// setup a dialog window
alertDialogBuilder.setCancelable(false)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
SUBJECT = editText.getText().toString();
PASS = "0";
DatabaseOperations DB = new DatabaseOperations(ctx);
DB.putInformation(DB, SUBJECT, PASS);
Toast.makeText(getBaseContext(), "Subject added", Toast.LENGTH_SHORT).show();
finish();
}
})
.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
// create an alert dialog
AlertDialog alert = alertDialogBuilder.create();
alert.show();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
表资料:
package cannon.gaming.mymarks;
import android.provider.BaseColumns;
/**
* Created by Asuspc on 01/07/2015.
*/
public class TableData {
public TableData()
{
}
public static abstract class TableInfo implements BaseColumns
{
public static final String USER_NAME = "user_name";
public static final String USER_PASS = "user_pass";
public static final String DATABASE_NAME = "user_info";
public static final String TABLE_NAME = "reg_info";
}
}
DatabaseOperations:
package cannon.gaming.mymarks;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
/**
* Created by Asuspc on 01/07/2015.
*/
public class DatabaseOperations extends SQLiteOpenHelper {
public static final int database_version = 1;
public String CREATE_QUERY = "CREATE TABLE "+ TableData.TableInfo.TABLE_NAME+"("+ TableData.TableInfo.USER_NAME+" TEXT,"+ TableData.TableInfo.USER_PASS+" TEXT);";
public DatabaseOperations(Context context) {
super(context, TableData.TableInfo.DATABASE_NAME, null, database_version);
Log.d("Database Operations", "Database created");
}
@Override
public void onCreate(SQLiteDatabase sdb)
{
sdb.execSQL(CREATE_QUERY);
Log.d("Database Operations", "Table created");
}
@Override
public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2)
{
}
public void putInformation(DatabaseOperations dop,String name, String pass)
{
SQLiteDatabase SQ = dop.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(TableData.TableInfo.USER_NAME, name);
cv.put(TableData.TableInfo.USER_PASS, pass);
long k = SQ.insert(TableData.TableInfo.TABLE_NAME, null, cv);
Log.d("Database Operations", "One row inserted");
}
public Cursor getInformation(DatabaseOperations dop)
{
SQLiteDatabase SQ = dop.getReadableDatabase();
String[] columns = {TableData.TableInfo.USER_NAME, TableData.TableInfo.USER_PASS};
Cursor CR = SQ.query(TableData.TableInfo.TABLE_NAME, columns, null, null, null, null, null);
return CR;
}
}
现在让我解释一下。 当我按下"按钮添加"按钮它会让我明显输入主题名称,并将其保存在数据库中。
但我无法做到的是,我想在MainActivity上显示所有数据库。 它应该是这样的:
我想让每个主题都可以点击,所以当你点击它时,它应该显示该主题的所有标记,并允许你添加或删除它们。
现在,我猜,显示数据不应该那么难,但我仍然需要你的帮助。 但是让每个主题都可以点击,我真的不知道如何。 每个主题都有自己的标记,我不知道,它是指每个新主题或新数据库的新活动还是什么?
编辑:
现在的MainActivity:
package cannon.gaming.mymarks;
import android.annotation.TargetApi;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.os.Build;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.text.Html;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class MainActivity extends ActionBarActivity {
String SUBJECT, PASS;
Context CTX = this;
private SimpleCursorAdapter adapter;
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().hide();
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
/*Button buttonAdd = (Button) findViewById(R.id.buttonAdd);
buttonAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(v.getContext(), RegisterActivity.class);
intent.setFlags(intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.putExtra("EXIT", true);
startActivityForResult(intent, 0);
}
});*/
Button buttonAdd = (Button) findViewById(R.id.buttonAdd);
displayListView();
buttonAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
showInputDialog();
}
});
}
protected void showInputDialog() {
// get prompts.xml view
LayoutInflater layoutInflater = LayoutInflater.from(MainActivity.this);
View promptView = layoutInflater.inflate(R.layout.activity_dialog, null);
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(MainActivity.this);
alertDialogBuilder.setView(promptView);
final EditText editText = (EditText) promptView.findViewById(R.id.edittext);
// setup a dialog window
alertDialogBuilder.setCancelable(false)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
SUBJECT = editText.getText().toString();
PASS = "0";
DatabaseOperations DB = new DatabaseOperations(CTX);
DB.putInformation(DB, SUBJECT, PASS);
Toast.makeText(getBaseContext(), "Subject added", Toast.LENGTH_SHORT).show();
adapter.notifyDataSetChanged();
displayListView();
}
})
.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
// create an alert dialog
AlertDialog alert = alertDialogBuilder.create();
alert.show();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
private void displayListView()
{
DatabaseOperations DOP = new DatabaseOperations(CTX);
Cursor CR = DOP.getInformation(DOP);
CR.moveToFirst();
// The desired columns to be bound
String[] columns = new String[]{
TableData.TableInfo.USER_NAME,
TableData.TableInfo.USER_PASS
};
// the XML defined views which the data will be bound to
int[] to = new int[]{
R.id.code,
R.id.name,
};
adapter = new SimpleCursorAdapter(
this, R.layout.activity_login,
CR,
columns,
to,
0);
ListView listView = (ListView) findViewById(R.id.listView);
// Assign adapter to ListView
listView.setAdapter(adapter);
}
}
答案 0 :(得分:1)
要显示数据,您应该使用ListView和CursorAdapter。 以下是您的示例代码:http://www.mysamplecode.com/2012/07/android-listview-cursoradapter-sqlite.html
在该示例代码中,您可以看到:
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> listView, View view,
int position, long id) {
// Get the cursor, positioned to the corresponding row in the result set
Cursor cursor = (Cursor) listView.getItemAtPosition(position);
// Get the state's capital from this row in the database.
String countryCode =
cursor.getString(cursor.getColumnIndexOrThrow("code"));
Toast.makeText(getApplicationContext(),
countryCode, Toast.LENGTH_SHORT).show();
}
});
OnItemClickListener将帮助您处理单击列表视图中的项目的时间。
希望这会对你有所帮助。