Android Studio实现简单的通讯录
网上找的一个单页面通讯录,修改之后将添加联系人和修改/删除联系人分为两个独立页面
MainActivity
package com.example.test; import androidx.appcompat.app.AppCompatActivity; import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.text.method.ScrollingMovementMethod; import android.view.View; import android.view.inputmethod.InputMethodManager; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends AppCompatActivity implements View.OnClickListener{ MyHelper myHelper; private TextView tvShow; private Button btnAdd; private Button btnQuery; private Button btnUpdate; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); myHelper = new MyHelper(this); init(); } private void init(){ tvShow = (TextView)findViewById(R.id.tv_show); btnAdd = (Button)findViewById(R.id.btn_add); btnQuery = (Button)findViewById(R.id.btn_query); btnUpdate = (Button)findViewById(R.id.btn_update); btnAdd.setOnClickListener(this); //Button控件设置监听 btnQuery.setOnClickListener(this); btnUpdate.setOnClickListener(this); findViewById(R.id.traceroute_rootview).setOnClickListener(this); tvShow.setMovementMethod(ScrollingMovementMethod.getInstance()); //设置文本滚动 } public void onClick(View v){ SQLiteDatabase db; switch (v.getId()){ case R.id.traceroute_rootview: InputMethodManager imm=(InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE); imm.hideSoftInputFromWindow(v.getWindowToken(),0); break; case R.id.btn_add: //添加联系人 Intent intent=new Intent(MainActivity.this,nextActivity.class); startActivity(intent); break; case R.id.btn_query: //查询联系人 db = myHelper.getReadableDatabase(); Cursor cursor = db.rawQuery("select name,phone from person",null); if (cursor.getCount() == 0){ tvShow.setText(""); Toast.makeText(this,"当前无联系人",Toast.LENGTH_SHORT).show(); }else { cursor.moveToFirst(); tvShow.setText("Name:" + cursor.getString(0) + " ; Tel:" + cursor.getString(1)); while (cursor.moveToNext()){ tvShow.append("\n" + "Name:" + cursor.getString(0) + " ; Tel:" + cursor.getString(1)); } } cursor.close(); db.close(); break; case R.id.btn_update: //修改联系人 Intent intent1=new Intent(MainActivity.this,xiugaiActivity.class); startActivity(intent1); break; } } }
nextActivity
package com.example.test; import androidx.appcompat.app.AppCompatActivity; import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.database.sqlite.SQLiteDatabase; import android.view.View; import android.view.inputmethod.InputMethodManager; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; public class nextActivity extends AppCompatActivity implements View.OnClickListener { MyHelper myHelper; private EditText etName; private EditText etPhone; private Button btnAdd; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.next); myHelper = new MyHelper(this); init(); } private void init(){ etName = (EditText)findViewById(R.id.et_name); etPhone = (EditText)findViewById(R.id.et_phone); btnAdd = (Button)findViewById(R.id.btn_add); btnAdd.setOnClickListener(this); //Button控件设置监听 findViewById(R.id.traceroute_rootview).setOnClickListener(this); } public void onClick(View v){ String name; String phone; SQLiteDatabase db; switch (v.getId()) { case R.id.traceroute_rootview: InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE); imm.hideSoftInputFromWindow(v.getWindowToken(), 0); break; case R.id.btn_add: //添加联系人 name = etName.getText().toString().trim(); phone = etPhone.getText().toString().trim(); db = myHelper.getWritableDatabase(); if (name.equals("") || phone.equals("")) { //联系人信息不能为空 Toast.makeText(this, "联系人信息添加失败", Toast.LENGTH_SHORT).show(); } else { db.execSQL("insert into person (name,phone) values(?,?)", new Object[]{name, phone}); Toast.makeText(this, "联系人信息添加成功", Toast.LENGTH_SHORT).show(); } db.close(); Intent intent=new Intent(nextActivity.this,MainActivity.class); startActivity(intent); break; } } }
xiugaiActivity
package com.example.test; import androidx.appcompat.app.AppCompatActivity; import android.content.Context; import android.os.Bundle; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.text.method.ScrollingMovementMethod; import android.view.View; import android.view.inputmethod.InputMethodManager; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; public class xiugaiActivity extends AppCompatActivity implements View.OnClickListener{ MyHelper myHelper; private EditText etName; private EditText etPhone; private TextView tvShow; private Button btnQuery; private Button btnUpdate; private Button btnDelete; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.xiugai); myHelper = new MyHelper(this); init(); } private void init(){ etName = (EditText)findViewById(R.id.et_name); etPhone = (EditText)findViewById(R.id.et_phone); tvShow = (TextView)findViewById(R.id.tv_show); btnQuery = (Button)findViewById(R.id.btn_query); btnUpdate = (Button)findViewById(R.id.btn_update); btnDelete = (Button)findViewById(R.id.btn_delete); btnQuery.setOnClickListener(this); btnUpdate.setOnClickListener(this); btnDelete.setOnClickListener(this); findViewById(R.id.traceroute_rootview).setOnClickListener(this); tvShow.setMovementMethod(ScrollingMovementMethod.getInstance()); //设置文本滚动 } public void onClick(View v){ String name; String phone; SQLiteDatabase db; switch (v.getId()){ case R.id.traceroute_rootview: InputMethodManager imm=(InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE); imm.hideSoftInputFromWindow(v.getWindowToken(),0); break; case R.id.btn_query: //查询联系人 db = myHelper.getReadableDatabase(); Cursor cursor = db.rawQuery("select name,phone from person",null); if (cursor.getCount() == 0){ tvShow.setText(""); Toast.makeText(this,"当前无联系人",Toast.LENGTH_SHORT).show(); }else { cursor.moveToFirst(); tvShow.setText("Name:" + cursor.getString(0) + " ; Tel:" + cursor.getString(1)); while (cursor.moveToNext()){ tvShow.append("\n" + "Name:" + cursor.getString(0) + " ; Tel:" + cursor.getString(1)); } } cursor.close(); db.close(); break; case R.id.btn_update: //修改联系人 db = myHelper.getWritableDatabase(); name = etName.getText().toString().trim(); phone = etPhone.getText().toString().trim(); if (name.equals("") || phone.equals("")){ //联系人信息不能为空 Toast.makeText(this,"不存在该联系人",Toast.LENGTH_SHORT).show(); } else { db.execSQL("update person set name=?,phone=? where name=?", new Object[]{name, phone, name}); Toast.makeText(this,"联系人信息修改成功",Toast.LENGTH_SHORT).show(); } db.close(); break; case R.id.btn_delete: //删除联系人 db = myHelper.getWritableDatabase(); name = etName.getText().toString().trim(); phone = etPhone.getText().toString().trim(); if (name.equals("") || phone.equals("")){ //联系人信息不能为空 Toast.makeText(this,"不存在该联系人",Toast.LENGTH_SHORT).show(); } else { db.execSQL("delete from person where name=? and phone=?", new Object[]{name, phone}); Toast.makeText(this,"联系人信息删除成功",Toast.LENGTH_SHORT).show(); } db.close(); break; } } }
MyHelper
package com.example.test; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; public class MyHelper extends SQLiteOpenHelper{ public MyHelper(Context context){ super(context, "alan.db", null ,2); } @Override public void onCreate(SQLiteDatabase db){ db.execSQL("create table person(id integer primary key autoincrement,name varchar(20),phone varchar(20) unique)"); } public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){ } }
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/traceroute_rootview" android:background="@color/white" android:clickable="true" android:gravity="center_horizontal" tools:context=".MainActivity"> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="通 讯 录" android:textSize="30dp" android:textStyle="italic" android:gravity="center" android:textColor="@color/black"> </TextView> <Button android:id="@+id/btn_add" android:layout_width="match_parent" android:layout_height="wrap_content" android:background="@drawable/shape" android:text=" 添加联系人" android:textSize="16dp" android:textColor="#c2c8ec" android:textStyle="bold"/> <Button android:id="@+id/btn_query" android:layout_width="match_parent" android:layout_height="wrap_content" android:background="@drawable/shape" android:text="查看联系人" android:textSize="16dp" android:textColor="#c2c8ec" android:textStyle="bold"/> <Button android:id="@+id/btn_update" android:layout_width="match_parent" android:layout_height="wrap_content" android:background="@drawable/shape" android:text=" 修改联系人" android:textSize="16dp" android:textColor="#c2c8ec" android:textStyle="bold"/> <TextView android:id="@+id/tv_show" android:layout_width="match_parent" android:layout_height="180dp" android:scrollbars="vertical" android:layout_below="@+id/lineFour" android:layout_marginTop="20dp" android:layout_marginLeft="20dp" android:layout_marginRight="18dp" android:textColor="#c2c8ec" android:textSize="24dp"/> </LinearLayout>
next.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/traceroute_rootview" android:background="@color/white" android:clickable="true" android:orientation="vertical" android:gravity="center_horizontal" tools:context=".nextActivity"> <LinearLayout android:id="@+id/lineTwo" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/lineOne" android:layout_marginTop="20dp" android:layout_marginLeft="18dp" android:layout_marginRight="18dp"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="姓 名 : " android:textSize="18dp" android:textStyle="bold"/> <EditText android:id="@+id/et_name" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入姓名" android:textSize="16dp" android:maxLines="1" android:singleLine="true" android:maxLength="14"/> </LinearLayout> <LinearLayout android:id="@+id/lineTree" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/lineTwo" android:layout_marginTop="10dp" android:layout_marginLeft="18dp" android:layout_marginRight="18dp"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="电 话 : " android:textSize="18dp" android:textStyle="bold"/> <EditText android:id="@+id/et_phone" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入手机号码" android:textSize="16dp" android:maxLines="1" android:singleLine="true" android:maxLength="11"/> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/lineFour" android:layout_below="@+id/lineTree" android:layout_marginTop="30dp" android:layout_marginLeft="18dp" android:layout_marginRight="18dp" android:orientation="horizontal"> <Button android:id="@+id/btn_add" android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@drawable/shape" android:layout_weight="1" android:text=" 确 定 " android:textSize="16dp" android:textColor="#c2c8ec" android:textStyle="bold"/> </LinearLayout> </RelativeLayout> xiugai.xml <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/traceroute_rootview" android:background="@color/white" android:clickable="true" android:orientation="vertical" android:gravity="center_horizontal" tools:context=".xiugaiActivity"> <LinearLayout android:id="@+id/lineTwo" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/lineOne" android:layout_marginTop="20dp" android:layout_marginLeft="18dp" android:layout_marginRight="18dp"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="姓 名 : " android:textSize="18dp" android:textStyle="bold"/> <EditText android:id="@+id/et_name" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint=" 请输入姓名" android:textSize="16dp" android:maxLines="1" android:singleLine="true" android:maxLength="14"/> </LinearLayout> <LinearLayout android:id="@+id/lineTree" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/lineTwo" android:layout_marginTop="10dp" android:layout_marginLeft="18dp" android:layout_marginRight="18dp"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="电 话 : " android:textSize="18dp" android:textStyle="bold"/> <EditText android:id="@+id/et_phone" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint=" 请输入手机号码" android:textSize="16dp" android:maxLines="1" android:singleLine="true" android:maxLength="11"/> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/lineFour" android:layout_below="@+id/lineTree" android:layout_marginTop="30dp" android:layout_marginLeft="18dp" android:layout_marginRight="18dp" android:orientation="horizontal"> <Button android:id="@+id/btn_query" android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@drawable/shape" android:layout_weight="1" android:layout_marginLeft="4dp" android:text="查看联系人" android:textSize="16dp" android:textColor="#c2c8ec" android:textStyle="bold"/> <Button android:id="@+id/btn_update" android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@drawable/shape" android:layout_weight="1" android:layout_marginLeft="4dp" android:text=" 修 改 " android:textSize="16dp" android:textColor="#c2c8ec" android:textStyle="bold"/> <Button android:id="@+id/btn_delete" android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@drawable/shape" android:layout_weight="1" android:layout_marginLeft="4dp" android:text=" 删 除 " android:textSize="16dp" android:textColor="#c2c8ec" android:textStyle="bold"/> </LinearLayout> <TextView android:id="@+id/tv_show" android:layout_width="match_parent" android:layout_height="180dp" android:scrollbars="vertical" android:layout_below="@+id/lineFour" android:layout_marginTop="20dp" android:layout_marginLeft="20dp" android:layout_marginRight="18dp" android:textColor="#c2c8ec" android:textSize="24dp"/> </RelativeLayout>
Mainfest
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.test"> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/Theme.Test"> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name=".nextActivity"></activity> <activity android:name=".xiugaiActivity"></activity> </application> </manifest>
初学android,程序还存在许多bug,大家多提修改建议。
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