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。
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持自学编程网。