dbadpter的分析

package edu.hrbeu.SQLiteDemo;


import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;


public class SQLiteDemoActivity extends Activity {
    /** Called when the activity is first created. */
private DBAdapter dbAdepter ;

private EditText nameText;
private EditText ageText;
private EditText heightText;
private EditText idEntry;

private TextView labelView;
private TextView displayView;



    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        nameText = (EditText)findViewById(R.id.name);
        ageText = (EditText)findViewById(R.id.age);
        heightText = (EditText)findViewById(R.id.height);
        idEntry = (EditText)findViewById(R.id.id_entry);
        
        labelView = (TextView)findViewById(R.id.label);
        displayView = (TextView)findViewById(R.id.display);
        
        
        
        Button addButton = (Button)findViewById(R.id.add);
        Button queryAllButton = (Button)findViewById(R.id.query_all);      
        Button clearButton = (Button)findViewById(R.id.clear);
        Button deleteAllButton = (Button)findViewById(R.id.delete_all);
        
        Button queryButton = (Button)findViewById(R.id.query);
        Button deleteButton = (Button)findViewById(R.id.delete);
        Button updateButton = (Button)findViewById(R.id.update);
        
        
        addButton.setOnClickListener(addButtonListener); 
        queryAllButton.setOnClickListener(queryAllButtonListener);     
        clearButton.setOnClickListener(clearButtonListener);
        deleteAllButton.setOnClickListener(deleteAllButtonListener);      
        
        queryButton.setOnClickListener(queryButtonListener);
        deleteButton.setOnClickListener(deleteButtonListener);
        updateButton.setOnClickListener(updateButtonListener);
        //这里清楚的说明了监听和函数处理的不同，他们完全是可以分开操作的
        
        
        dbAdepter = new DBAdapter(this);
        //这里面的this应该代指的是整个主界面函数，用整个主界面函数用作context参数是什么意思呢？
        
        dbAdepter.open();
    }
    
    OnClickListener addButtonListener = new OnClickListener() {
@Override
public void onClick(View v) {
People people = new People();
people.Name = nameText.getText().toString();
people.Age = Integer.parseInt(ageText.getText().toString());
people.Height = Float.parseFloat(heightText.getText().toString());
long colunm = dbAdepter.insert(people);
if (colunm == -1 ){
labelView.setText("添加过程错误！");
} else {
labelView.setText("成功添加数据，ID："+String.valueOf(colunm));

}
}
    };
    
    OnClickListener queryAllButtonListener = new OnClickListener() {
@Override
public void onClick(View v) {
People[] peoples = dbAdepter.queryAllData();//这里是一次将所有的数据库中的内容全部取出来
if (peoples == null){
labelView.setText("数据库中没有数据");
return;
}
labelView.setText("数据库：");
String msg = "";
for (int i = 0 ; i<peoples.length; i++){
msg += peoples[i].toString()+"\n";
}
displayView.setText(msg);
}
    };
    
    OnClickListener clearButtonListener = new OnClickListener() {


@Override
public void onClick(View v) {
displayView.setText("");
}
    };
    
    OnClickListener deleteAllButtonListener = new OnClickListener() {
@Override
public void onClick(View v) {
dbAdepter.deleteAllData();
String msg = "数据全部删除";
labelView.setText(msg);
}
    };
    
    OnClickListener queryButtonListener = new OnClickListener() {
@Override
public void onClick(View v) {
int id = Integer.parseInt(idEntry.getText().toString());
People[] peoples = dbAdepter.queryOneData(id);

if (peoples == null){
labelView.setText("数据库中没有ID为"+String.valueOf(id)+"的数据");
return;
}
labelView.setText("数据库：");
displayView.setText(peoples[0].toString());
}
    };
    
    OnClickListener deleteButtonListener = new OnClickListener() {
@Override
public void onClick(View v) {
long id = Integer.parseInt(idEntry.getText().toString());
long result = dbAdepter.deleteOneData(id);//其实这里应该再次加上一个判断函数用来判断这个函数是不是有正确的ID号码。

String msg = "删除ID为"+idEntry.getText().toString()+"的数据" + (result>0?"成功":"失败");
labelView.setText(msg);
}
    };
    
    OnClickListener updateButtonListener = new OnClickListener() {
@Override
public void onClick(View v) {
People people = new People();
people.Name = nameText.getText().toString();
people.Age = Integer.parseInt(ageText.getText().toString());
people.Height = Float.parseFloat(heightText.getText().toString());
long id = Integer.parseInt(idEntry.getText().toString());
long count = dbAdepter.updateOneData(id, people);
if (count == -1 ){
labelView.setText("更新错误！");
} else {
labelView.setText("更新成功，更新数据"+String.valueOf(count)+"条");

}
}
    };


}