Java 如何在代码中插入intent方法，以便在单击按钮时显示第二个活动

下面是提供在SQLite中添加记录数据的java活动。我的问题是，我如何在点击按钮时插入一些代码，它将显示第二个活动。我不知道应该在哪里插入。也不知道应该是什么代码。请帮帮我

import java.sql.PreparedStatement;

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

public class AddStudent extends Activity {
DatabaseStudent mHelper;
SQLiteDatabase mDb;


public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.add);

    mHelper = new DatabaseStudent(this);
    mDb = mHelper.getWritableDatabase();

    final EditText editName = (EditText)findViewById(R.id.editName);
    final EditText editLastName = (EditText)findViewById(R.id.editLastName);


    ImageView buttonAdd = (ImageView)findViewById(R.id.imageAdd);

    buttonAdd.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            String name = editName.getText().toString();
            String lastname = editLastName.getText().toString();
            String condition = getIntent().getStringExtra("Condition");
            double school = getIntent().getDoubleExtra("Intent", 0);

            //Date&Time
            java.util.Date dt = new java.util.Date();
            java.text.SimpleDateFormat sdf = 
                 new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            String currentTime = sdf.format(dt);

            if(name.length() != 0 && lastname.length() != 0 
                     ) {//&& school.length() != 0

                Cursor mCursor = mDb.rawQuery("SELECT * FROM " 
                        + DatabaseStudent.TABLE_NAME + " WHERE " 
                        + DatabaseStudent.COL_NAME + "='" + name + "'" 
                        + " AND " + DatabaseStudent.COL_LASTNAME + "='" 
                        + lastname + "'" + " AND " 
                        + DatabaseStudent.COL_SCHOOL + "='" + school //add COL_SCHOOL = currentTime
                        + "'"+ " AND " + DatabaseStudent.COL_TIME + "='" + currentTime
                        + "'"+ " AND " + DatabaseStudent.COL_CON + "='" + condition
                        + "'", null);

                if(mCursor.getCount() == 0) {
                    mDb.execSQL("INSERT INTO " + DatabaseStudent.TABLE_NAME 
                            + " (" + DatabaseStudent.COL_NAME 
                            + ", " + DatabaseStudent.COL_LASTNAME 
                            + ", " + DatabaseStudent.COL_SCHOOL 
                            + ", " + DatabaseStudent.COL_TIME 
                            + ", " + DatabaseStudent.COL_CON 
                            + ") VALUES ('" + name + "', '" + lastname 
                            + "', '" + school + "', '" + currentTime + "', '" + condition + "');");



                    editName.setText("");
                    editLastName.setText("");


                    Toast.makeText(getApplicationContext()
                            , "Already added"
                            , Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(getApplicationContext()
                            , "This data is exist"
                            , Toast.LENGTH_SHORT).show();
                }

            } else {
                Toast.makeText(getApplicationContext()
                        , "Please fill in the blank"
                        , Toast.LENGTH_SHORT).show();
            }
        }
    });

}

public void onStop() {
    super.onStop();
    mHelper.close();
    mDb.close();
}

---

}

点击onClick方法中的按钮时，您可能希望插入任何要执行的代码，如下图所示：

buttonAdd.setOnClickListener(new OnClickListener() {
    public void onClick(View v) {

    // do stuff when buttonAdd is clicked

    }
});

现在，您可以在onClick方法中使用intent来开始第二个活动，如下所示：

buttonAdd.setOnClickListener(new OnClickListener() {
    public void onClick(View v) {

        Intent intent = new Intent(current_activity.this, second_activity.class);
        startActivity(intent);
    }
});

---

有关更多详细信息，您可以参考以下内容：

更好：避免来自Activity的所有数据库事务有关更多详细信息，以下内容可能有用（尽管并非真正针对初学者）：