第五周第六周作业
1.返回键实现对话框弹出是否退出应用程序
package com.example.chap5; 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("是", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); MainActivity.this.finish(); } }) .setNegativeButton("否", 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.chap6; 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 num0=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 num0=which; } }) .setPositiveButton("是",new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub if(num0==0){ Toast.makeText(MainActivity.this, "您选择的是男", Toast.LENGTH_LONG).show(); }else{ Toast.makeText(MainActivity.this, "您选择的是女", Toast.LENGTH_SHORT).show(); } dialog.dismiss(); } }) .setNegativeButton("否", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub dialog.dismiss(); } }); AlertDialog dialog=builder.create(); dialog.show(); } }
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="#8BEC1B"> <TextView android:layout_width="wrap_content" android:layout_height="35dp" android:text="1.TextView显示文本信息" android:textStyle="italic" android:textColor="#E71D1D" android:layout_marginTop="20dp" android:layout_marginLeft="50dp" android:textSize="30sp"/> <Button android:layout_width="match_parent" android:layout_height="60dp" android:layout_marginLeft="20dp" android:layout_marginTop="60dp" android:layout_marginRight="20dp" android:text="2.按钮" android:textColor="#E71D1D" android:textSize="30sp" /> <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_marginTop="120dp" android:textColor="#E71D1D" android:layout_marginLeft="35dp"/> <RadioGroup android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:orientation="horizontal"/> <RadioButton android:id="@+id/rb_1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="4.男" android:textSize="30sp" android:layout_marginTop="180dp" android:textColor="#E71D1D" android:layout_marginLeft="35dp"/> <RadioButton android:id="@+id/rb_2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="女" android:layout_toRightOf="@id/rb_1" android:textSize="30sp" android:layout_marginTop="180dp" android:textColor="#E71D1D" android:layout_marginLeft="35dp"/> <CheckBox android:id="@+id/cb_1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="电脑" android:textColor="#E71D1D" android:textSize="30sp" android:layout_marginTop="230dp" android:layout_marginLeft="35dp"/> <CheckBox android:id="@+id/cb_2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="手机" android:textColor="#E71D1D" android:textSize="30sp" android:layout_below="@id/cb_1" android:layout_marginTop="10dp" android:layout_marginLeft="35dp"/> </RelativeLayout>
4.教材p76页 图3—17购物商城界面
<?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" android:background="#7AD610" tools:context=".MainActivity"> <TextView android:id="@+id/tv1" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="1.TextView显示文本信息" android:textColor="#F81D0D" android:textSize="25sp" android:textStyle="italic" android:gravity="center" android:layout_marginTop="30dp" /> <Button android:id="@+id/bt1" android:layout_width="350dp" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_below="@+id/tv1" android:text="2.按钮" android:textColor="#F81D0D" android:textSize="25sp" android:layout_marginTop="10dp" android:padding="10dp"/> <EditText android:id="@+id/et1" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="3.编辑框:请输入信息" android:textColorHint="#F81D0D" android:textSize="25sp" android:layout_below="@+id/bt1" android:layout_alignStart="@+id/bt1" android:layout_marginTop="5dp" android:padding="10dp" android:layout_alignLeft="@+id/bt1" /> <RadioGroup android:id="@+id/rg1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@+id/et1" android:layout_alignLeft="@+id/et1" android:orientation="horizontal" android:padding="10dp"> <RadioButton android:id="@+id/rb1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="4.男" android:textColor="#F81D0D" android:textSize="25sp" /> <RadioButton android:id="@+id/rb2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="女" android:textColor="#F81D0D" android:textSize="25sp" /> </RadioGroup> <LinearLayout android:id="@+id/ll1" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:layout_alignLeft="@+id/rg1" android:layout_below="@id/rg1"> <CheckBox android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="电脑" android:textSize="25sp" android:textColor="#F81D0D" /> <CheckBox android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="手机" android:textSize="25sp" android:textColor="#F81D0D" /> </LinearLayout> </RelativeLayout>
<?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" android:background="#7AD610" tools:context=".MainActivity"> <TextView android:id="@+id/tv1" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="1.TextView显示文本信息" android:textColor="#F81D0D" android:textSize="25sp" android:textStyle="italic" android:gravity="center" android:layout_marginTop="30dp" /> <Button android:id="@+id/bt1" android:layout_width="350dp" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_below="@+id/tv1" android:text="2.按钮" android:textColor="#F81D0D" android:textSize="25sp" android:layout_marginTop="10dp" android:padding="10dp"/> <EditText android:id="@+id/et1" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="3.编辑框:请输入信息" android:textColorHint="#F81D0D" android:textSize="25sp" android:layout_below="@+id/bt1" android:layout_alignStart="@+id/bt1" android:layout_marginTop="5dp" android:padding="10dp" android:layout_alignLeft="@+id/bt1" /> <RadioGroup android:id="@+id/rg1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@+id/et1" android:layout_alignLeft="@+id/et1" android:orientation="horizontal" android:padding="10dp"> <RadioButton android:id="@+id/rb1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="4.男" android:textColor="#F81D0D" android:textSize="25sp" /> <RadioButton android:id="@+id/rb2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="女" android:textColor="#F81D0D" android:textSize="25sp" /> </RadioGroup> <LinearLayout android:id="@+id/ll1" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:layout_alignLeft="@+id/rg1" android:layout_below="@id/rg1"> <CheckBox android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="电脑" android:textSize="25sp" android:textColor="#F81D0D" /> <CheckBox android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="手机" android:textSize="25sp" android:textColor="#F81D0D" /> </LinearLayout> </RelativeLayout>
m package com.example.a56zhou4; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.ListAdapter; import android.widget.ListView; import android.widget.TextView; public class MainActivity extends AppCompatActivity { 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/kg", "300元", "350元", "10/kg", "280元"}; private int[] icons = {R.drawable.table, R.drawable.apple, R.drawable.cake, R.drawable.wireclothes, R.drawable.kiwifruit, R.drawable.scarf}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mListView = (ListView) findViewById(R.id.lv); MyBaseAdapter mAdapter = new MyBaseAdapter(); mListView.setAdapter( mAdapter); } class MyBaseAdapter extends BaseAdapter { @Override public int getCount() { return titles.length; } @Override public Object getItem(int position) { return titles[position]; } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { View view = View.inflate(MainActivity.this, R.layout.item, 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; } } }