我如何在此代码中插入意图方法，当单击按钮时，它将显示第二个活动

Question

这是在SQLite中添加记录数据的java活动。我的问题是我如何在单击按钮时插入一些代码，它将显示第二个活动。我不知道我应该插入哪里。并且不知道代码应该是什么。请帮助我。

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();
}

}

Answer 1

当您在 onClick 方法中点击按钮时，您希望插入要执行的任何代码，如下所示：

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);
    }
});

您可以查阅以下内容以获取更多详细信息：http://developer.android.com/training/basics/firstapp/starting-activity.html