第五六周作业
1.返回键实现对话框弹出是否退出应用程序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(); }
import android.os.Bundle;
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）
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.实现如下布局界面
<?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" 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
activity_main.xml:<?xml version="1.0" encoding="utf-8"?> <LinearLayout 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:orientation="vertical"> <TextView android:id="@+id/tv" android:layout_width="match_parent" android:layout_height="50dp" android:text="购物商城" android:textColor="#E8E3E9" android:background="#C175CE" android:textSize="20sp" android:gravity="center"/> <ListView android:id="@+id/lv" android:layout_width="match_parent" android:layout_height="wrap_content"/> </LinearLayout>
list_item.xml:<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:padding="15dp"> <ImageView android:id="@+id/iv" android:layout_width="100dp" android:layout_height="80dp" android:layout_centerVertical="true"/> <RelativeLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerVertical="true" android:layout_marginLeft="10dp" android:layout_toRightOf="@id/iv"> <TextView android:id="@+id/title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="桌子" android:textSize="20sp" android:textColor="#4B4343"/> <TextView android:id="@+id/tv_p" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="价格" android:textSize="20sp" android:textColor="#F5A631" android:layout_below="@id/title" android:layout_marginTop="10dp"/> <TextView android:id="@+id/price" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="1800" android:textSize="20sp" android:textColor="#F5A631" android:layout_below="@id/title" android:layout_toRightOf="@id/tv_p" android:layout_marginTop="10dp"/> </RelativeLayout> </RelativeLayout>
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.ListView; import android.widget.TextView; public class MainActivity extends AppCompatActivity { private ListView mListView; //商品名称与价格数据集合 private String [] titles={"桌子","苹果","蛋糕","线衣","猕猴桃","围巾"}; private String [] prices={"1800元","10元/kg","300元","350元","10元/kg","280元"}; //图片数据集合 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);//初始化ListView控件 MyBaseAdapter myAdapter = new MyBaseAdapter();//创建一个Adapter实例 mListView.setAdapter(myAdapter);//设置Adapter } class MyBaseAdapter extends BaseAdapter{ @Override public int getCount() { //获取item的总数 return titles.length; } @Override public Object getItem(int i) { return titles[i]; } @Override public long getItemId(int i) { return i; } @Override public View getView(int i, View view, ViewGroup viewGroup) { View view1= View.inflate(MainActivity.this,R.layout.list_item,null); TextView title = (TextView)view1.findViewById(R.id.title); TextView price = (TextView)view1.findViewById(R.id.price); ImageView iv = (ImageView)view1.findViewById(R.id.iv); title.setText(titles[i]); price.setText(prices[i]); iv.setBackgroundResource(icons[i]); return view1; } } }
