第五，六周作业
package com.example.qmt; import androidx.appcompat.app.AlertDialog; import androidx.appcompat.app.AppCompatActivity; import android.content.DialogInterface; import android.os.Bundle; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } @Override public void onBackPressed(){ final AlertDialog dialog; AlertDialog.Builder builder=new AlertDialog.Builder(this) .setTitle("普通对话框") .setIcon(R.mipmap.ic_launcher) .setMessage("是否确定退出应用:") .setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); MainActivity.this.finish(); } }) .setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }); dialog=builder.create(); dialog.show(); } }
2.实现以下场景：从一个activity中点击一个按钮后，弹出一个单选按钮对话框，上面有“男”“女”两个选项，选定后，TOAST弹出 你选择了男，或你选择了女（参考书上改字体）
package com.example.myapplication; import android.os.Bundle; import android.app.Activity; import android.app.AlertDialog; import android.app.AlertDialog.Builder; import android.content.DialogInterface; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.Toast; public class MainActivity extends Activity implements OnClickListener { private int num=0; private int num1[]={0,1}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); findViewById(R.id.bt).setOnClickListener(this); } @Override public void onClick(View v) { // TODO Auto-generated method stub AlertDialog.Builder builder=new AlertDialog.Builder(this) .setTitle("性别") .setSingleChoiceItems(new String[]{"男","女"}, -1, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub num=which; } }) .setPositiveButton("确定",new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub if(num==0){ Toast.makeText(MainActivity.this, "你选择的是男", Toast.LENGTH_LONG).show(); }else{ Toast.makeText(MainActivity.this, "你选择的是女", Toast.LENGTH_SHORT).show(); } dialog.dismiss(); } }) .setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub dialog.dismiss(); } }); AlertDialog dialog=builder.create(); dialog.show(); } }
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <Button android:id="@+id/bt" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="请选择你的性别" /> </RelativeLayout>
3.布局(详见:Android第五周上机word文档)
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" android:background="#0DFF18"> <TextView android:layout_width="match_parent" android:layout_height="40dp" android:text="1.TextView显示的文本信息" android:textSize="29sp" android:layout_marginLeft="40dp" android:layout_marginRight="20dp" android:layout_marginTop="30dp" android:textColor="#FF0000" /> <Button android:layout_width="match_parent" android:layout_height="60dp" android:text="2.按钮" android:textSize="30sp" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:layout_marginTop="90dp" android:textColor="#FF0000"/> <EditText android:layout_width="match_parent" android:layout_height="60dp" android:text="3.编辑框：请输入信息" android:textSize="30sp" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:layout_marginTop="180dp" android:textColor="#FF0000"/> <RadioGroup android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:orientation="horizontal"> <RadioButton android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="4.男" android:textSize="30sp" android:textColor="#FF0000" android:layout_marginTop="250dp"/> <RadioButton android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="女" android:textSize="30sp" android:textColor="#FF0000" android:layout_marginTop="250dp" /> </RadioGroup> <CheckBox android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="电脑" android:textColor="#FF0000" android:textSize="30sp" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:layout_marginTop="300dp"/> <CheckBox android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="手机" android:textColor="#FF0000" android:textSize="30sp" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:layout_marginTop="340dp"/> </RelativeLayout>
4.教材p76页 图3—17购物商城界面
package itcast.cn; import android.app.Activity; import android.app.AlertDialog; import android.content.DialogInterface; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ListView; import android.widget.TextView; import android.widget.ImageView; public class Main2Activity extends Activity{ private ListView mListView; private String[] titles={"桌子","苹果","蛋糕","线衣","猕猴桃","围巾"}; private String[] prices={"1800元","10元/千克","300元","350"+"元","10元/kg","280元"}; private int[] icons={R.drawable.table,R.drawable.apple,R.drawable.cake,R.drawable.wireclothes,R.drawable.kiwifruit,R.drawable.scarf}; protected void onCreate(Bundle savedInstancestate){ super.onCreate(savedInstancestate); setContentView(R.layout.activity_main2); mListView=(ListView)findViewById(R.id.lv); MyBaseAdapter mAdapter =new MyBaseAdapter(); mListView.setAdapter(mAdapter); } class MyBaseAdapter extends BaseAdapter{ public int getCount(){ return titles.length; } public Object getItem(int position){ return titles[position]; } public long getItemId(int position) { return position; } public View getView(int position,View convertView,ViewGroup parent){ View view=View.inflate(Main2Activity.this,R.layout.activity_main3,null); TextView title=(TextView)view.findViewById(R.id.title); TextView price=(TextView)view.findViewById(R.id.price); ImageView iv=(ImageView)view.findViewById(R.id.iv); title.setText(titles[position]); price.setText(prices[position]); iv.setBackgroundResource(icons[position]); return view; } } }
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <TextView android:layout_width="match_parent" android:layout_height="80dp" android:gravity="center" android:text="购物商城" android:textColor="#CC0000" android:textSize="40dp" android:background="#33FFFF"></TextView> <ListView android:id="@+id/lv" android:layout_width="wrap_content" android:layout_height="wrap_content"></ListView> </LinearLayout>
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <ImageView android:layout_width="200dp" android:layout_height="200dp" android:id="@+id/iv" /> <RelativeLayout android:layout_width="match_parent" android:layout_height="match_parent" android:layout_toRightOf="@id/iv" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/title" android:layout_marginTop="50dp" android:layout_marginLeft="15dp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="价格:" android:id="@+id/jg" android:layout_below="@id/title" android:layout_marginTop="50dp" android:layout_marginLeft="15dp"/> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/price" android:layout_toRightOf="@id/jg" android:layout_below="@id/title" android:layout_marginTop="50dp" android:layout_marginLeft="15dp"/> </RelativeLayout> </LinearLayout>
