首先是SQLite數據庫的DAO標準CRUD操作：
這裏只放出main,java中的部分代碼，其餘可直接去碼雲自取：碼雲連接
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
private MyDAO myDAO; //數據庫訪問對象
private ListView listView;
private List<Map<String,Object>> listData;
private Map<String,Object> listItem;
private SimpleAdapter listAdapter;
private EditText et_name; //數據表包含3個字段，第1字段爲自增長類型
private EditText et_age;
private String selId=null; //選擇項id
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button bt_add= (Button) findViewById(R.id.bt_add);bt_add.setOnClickListener(this);
Button bt_modify=(Button)findViewById(R.id.bt_modify);bt_modify.setOnClickListener(this);
Button bt_del=(Button)findViewById(R.id.bt_del);bt_del.setOnClickListener(this);
et_name=(EditText)findViewById(R.id.et_name);
et_age=(EditText)findViewById(R.id.et_age);
myDAO = new MyDAO(this); //創建數據庫訪問對象
if(myDAO.getRecordsNumber()==0) { //防止重複運行時重複插入記錄
myDAO.insertInfo("xuhuan", 21); //插入記錄
myDAO.insertInfo("xill", 21); //插入記錄
}
displayRecords(); //顯示記錄
}
public void displayRecords(){ //顯示記錄方法定義
listView = (ListView)findViewById(R.id.listView);
listData = new ArrayList<Map<String,Object>>();
Cursor cursor = myDAO.allQuery();
while (cursor.moveToNext()){
int id=cursor.getInt(0); //獲取字段值
String name=cursor.getString(1);
//int age=cursor.getInt(2);
int age=cursor.getInt(cursor.getColumnIndex("age"));//推薦此種方式
listItem=new HashMap<String,Object>(); //必須在循環體裏新建
listItem.put("_id", id); //第1參數爲鍵名，第2參數爲鍵值
listItem.put("name", name);
listItem.put("age", age);
listData.add(listItem); //添加一條記錄
}
listAdapter = new SimpleAdapter(this,
listData,
R.layout.list_item, //自行創建的列表項佈局
new String[]{"_id","name","age"},
new int[]{R.id.tv_id,R.id.tvname,R.id.tvage});
listView.setAdapter(listAdapter); //應用適配器
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { //列表項監聽
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Map<String,Object> rec= (Map<String, Object>) listAdapter.getItem(position); //從適配器取記錄
et_name.setText(rec.get("name").toString()); //刷新文本框
et_age.setText(rec.get("age").toString());
Log.i("ly",rec.get("_id").toString());
selId=rec.get("_id").toString(); //供修改和刪除時使用
}
});
}
@Override
public void onClick(View v) { //實現的接口方法
if(selId!=null) { //選擇了列表項後，可以增加/刪除/修改
String p1 = et_name.getText().toString().trim();
int p2 = Integer.parseInt(et_age.getText().toString());
switch (v.getId()){
case R.id.bt_add:
myDAO.insertInfo(p1,p2);
break;
case R.id.bt_modify:
myDAO.updateInfo(p1,p2,selId);
Toast.makeText(getApplicationContext(),"更新成功！",Toast.LENGTH_SHORT).show();
break;
case R.id.bt_del:
myDAO.deleteInfo(selId);
Toast.makeText(getApplicationContext(),"刪除成功！",Toast.LENGTH_SHORT).show();
et_name.setText(null);et_age.setText(null); selId=null; //提示
}
}else{ //未選擇列表項
if(v.getId()==R.id.bt_add) { //單擊添加按鈕
String p1 = et_name.getText().toString();
String p2=et_age.getText().toString();
if(p1.equals("")||p2.equals("")){ //要求輸入了信息
Toast.makeText(getApplicationContext(),"姓名和年齡都不能空！",Toast.LENGTH_SHORT).show();
}else{
myDAO.insertInfo(p1, Integer.parseInt(p2)); //第2參數轉型
}
} else{ //單擊了修改或刪除按鈕
Toast.makeText(getApplicationContext(),"請先選擇記錄！",Toast.LENGTH_SHORT).show();
}
}
displayRecords();//刷新ListView對象
}
}
另外附上運行圖片：
然後是as微信項目的第三板塊，這裏就只放上java的部分代碼吧，需要的同樣可以碼雲自取：微信第三頁面
package com.example.myweixin;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import android.content.DialogInterface;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.widget.FrameLayout;
import android.widget.ImageButton;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private Fragment mtab01=new weixinFragment();
private Fragment mtab02=new friendFragment();
private Fragment mtab03=new contactFragment();
private Fragment mtab04=new setFragment();
private FragmentManager fm;
private LinearLayout mtabweixin;
private LinearLayout mtabfrd;
private LinearLayout mtabaddress;
private LinearLayout mtabset;
private ImageButton mimgweixin;
private ImageButton mimgfrd;
private ImageButton mimgaddress;
private ImageButton mimgset;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
initFragment();
initEvent();
selectfragment(0);
}
private void initFragment(){
fm=getSupportFragmentManager();
FragmentTransaction transaction=fm.beginTransaction();
transaction.add(R.id.id_content,mtab01);
transaction.add(R.id.id_content,mtab02);
transaction.add(R.id.id_content,mtab03);
transaction.add(R.id.id_content,mtab04);
transaction.commit();
}
private void initView(){
mtabweixin=(LinearLayout) findViewById(R.id.weixin);
mtabfrd=(LinearLayout) findViewById(R.id.frd);
mtabaddress=(LinearLayout) findViewById(R.id.contact);
mtabset=(LinearLayout) findViewById(R.id.setting);
mimgweixin=findViewById(R.id.imageButton1);
mimgfrd=findViewById(R.id.imageButton2);
mimgaddress=findViewById(R.id.imageButton3);
mimgset=findViewById(R.id.imageButton4);
}
private void initEvent(){
mtabweixin.setOnClickListener(this);
mtabfrd.setOnClickListener(this);
mtabaddress.setOnClickListener(this);
mtabset.setOnClickListener(this);
}
private void hidefragment(FragmentTransaction transaction){
transaction.hide(mtab01);
transaction.hide(mtab02);
transaction.hide(mtab03);
transaction.hide(mtab04);
}
private void selectfragment(int i){
FragmentTransaction transaction=fm.beginTransaction();
hidefragment(transaction);
switch (i){
case 0:
transaction.show(mtab01);
mimgweixin.setImageResource(R.drawable.tab_weixin_pressed);
break;
case 1:
transaction.show(mtab02);
mimgfrd.setImageResource(R.drawable.tab_find_frd_pressed);
break;
case 2:
transaction.show(mtab03);
mimgaddress.setImageResource(R.drawable.tab_address_pressed);
break;
case 3:
transaction.show(mtab04);
mimgset.setImageResource(R.drawable.tab_settings_pressed);
break;
default:
break;
}
transaction.commit();
}
@Override
public void onClick(View v){
resetimg();
switch (v.getId()){
case R.id.imageButton1:
selectfragment(0);
System.out.println(v.getId());
break;
case R.id.imageButton2:
selectfragment(1);
break;
case R.id.imageButton3:
selectfragment(2);
break;
case R.id.imageButton4:
selectfragment(3);
break;
default:
break;
}
}
public void resetimg(){
mimgweixin.setImageResource(R.drawable.tab_weixin_normal);
mimgfrd.setImageResource(R.drawable.tab_find_frd_normal);
mimgaddress.setImageResource(R.drawable.tab_address_normal);
mimgset.setImageResource(R.drawable.tab_settings_normal);
}
}