Java第五六次作业

1.返回键实现对话框弹出是否退出应用程序

package cn.itcase.commondialog;

import android.os.Bundle;import android.app.AlertDialog;
import android.content.DialogInterface;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    @Override
    public void onBackPressed() {
        AlertDialog dialog;
        AlertDialog.Builder builder=new AlertDialog.Builder(this)
                .setTitle("普通对话框")
                .setMessage("是否退出至主菜单")
                .setIcon(R.drawable.ic_launcher_background)
                .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub
                        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

package com.example.myapplication;

import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class Main3Activity extends AppCompatActivity implements View.OnClickListener {
    private  TextView textView;
    private String[] textSizeArr={"男","女"};
    int textSize =1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
        findViewById(R.id.bt).setOnClickListener(this);
        textView=(TextView)findViewById(R.id.tv);
    }
    @Override
    public void onClick(View V){
        final AlertDialog dialog;
        AlertDialog.Builder builder =new AlertDialog.Builder(this)
                .setTitle("选择性别")
                .setIcon(R.mipmap.ic_launcher)
                .setSingleChoiceItems(new String[]{"男", "女"}, textSize, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialogInterface, int i) {
                        textSize=i;
                    }
                })
                .setPositiveButton("确定",new DialogInterface.OnClickListener(){
                    @Override
                    public void  onClick(DialogInterface dialog,int i){
                        if (i==1){
                            textView.setText("您的性别是：男");
                        }else {
                            textView.setText("您的性别是：女");
                        }
                        dialog.dismiss();
                    }
                })
                .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int i) {
                        dialog.dismiss();

                    }
                });
        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="#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

 

<?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"
    android:orientation="vertical">
<!--    tools:context=".MainActivity"-->
 
 
<!--    <TextView-->
<!--        android:layout_width="match_parent"-->
<!--        android:layout_height="45dp"-->
<!--        android:text=""-->
<!--        android:textSize="18sp"-->
<!--        android:textColor="#ffffff"-->
<!--        android:background="#ff8f03"-->
<!--        android:gravity="center"/>-->
 
    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:listSelector="#fefefefe"
        ></ListView>
 
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:padding="16dp" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ImageView
        android:id="@+id/iv"
        android:layout_width="120dp"
        android:layout_height="90dp"
 
        android:layout_centerVertical="true"
        ></ImageView>
    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
 
        android:layout_toRightOf="@+id/iv"
        android:layout_centerVertical="true">
        <TextView
            android:id="@+id/title"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:textSize="20sp"
            android:textColor="#000000"
            android:text="桌子"></TextView>
        <TextView
            android:id="@+id/prices"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="20sp"
            android:layout_marginTop="10dp"
            android:layout_below="@+id/title"
            android:text="价格："></TextView>
        <TextView
            android:id="@+id/price"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="1800"
            android:textSize="20sp"
            android:layout_below="@+id/title"
            android:layout_toRightOf="@+id/prices"
            android:textColor="#BA000000"
            android:layout_marginTop="10dp"></TextView>
    </RelativeLayout>
 
</RelativeLayout>

package com.example.shoppingapp;
 
import androidx.appcompat.app.AppCompatActivity;
import android.widget.TextView;
import android.widget.ImageView;
import android.widget.BaseAdapter;
import android.view.View;
import android.view.ViewGroup;
//import android.os.Build;
import android.os.Bundle;
//import android.widget.ListAdapter;
import android.widget.ListView;
 
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元/kg","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(Build savedInstanceState){
//        super.onCreate(savedInstanceState);
//        setContentView(R.layout.activity_main);
//
//    }
 
    @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.list_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;
        }
    }
}