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

package com.example.commentdialog;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.view.Menu;
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() {
        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) {
                        // TODO Auto-generated method stub
                        dialog.dismiss();
                        MainActivity.this.finish();

                    }
                })
                .setNegativeButton("取消",new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub
                        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）

<?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:id="@+id/tv1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:text="您的性别是"
        android:layout_marginTop="10dp"
        android:textColor="#592FA2"
        />
    <Button
        android:id="@+id/bt1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="选择"
        android:layout_marginTop="20dp"
        android:gravity="center"
        />



</LinearLayout>

package com.example.a56zhou2;

import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.content.DialogInterface;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import java.util.Locale;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    private TextView textView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.bt1).setOnClickListener(this);
        textView=(TextView) findViewById(R.id.tv1);

    }
    public void onClick(View view){
        final AlertDialog dialog;
        AlertDialog.Builder builder=new AlertDialog.Builder(this);
        builder.setTitle("您的性别是：");
        builder.setIcon(R.mipmap.ic_launcher);
        final String[]items=new String[]{"男","女"};
        builder.setSingleChoiceItems(items, -1, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                Toast.makeText(MainActivity.this,"您的性别是"+items[which],Toast.LENGTH_LONG).show();
                dialog.dismiss();
            }
        });
        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        })
                .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        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"
    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>

4.教材p76页 图3—17购物商城界面

 

a


<?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="购物商场"
        android:textSize="20sp"
        android:textColor="#10228D"
        android:background="#ECE4E4"
        android:gravity="center"
        />

    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

i



<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:padding="15dp"
    tools:context=".MainActivity" >
    <ImageView 
        android:id="@+id/iv"
        android:layout_height="120dp"
        android:layout_width="150dp"
        android:layout_centerVertical="true"/>

    <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="wrap_content"
            android:layout_height="wrap_content"
            android:text="桌子"
            android:textSize="21sp"
            android:textColor="#000000"/>
        <TextView
            android:id="@+id/tv_price"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="价格："
            android:textSize="21sp"
            android:layout_marginTop="10dp"
            android:layout_below="@+id/title"
            android:textColor="#4A13B6"/>
        <TextView
            android:id="@+id/price"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="1000"
            android:textSize="20sp"
            android:layout_below="@+id/title"
            android:layout_toRightOf="@+id/tv_price"
            android:textColor="#4A13B6"
            android:layout_marginTop="10dp"
            />
    </RelativeLayout>
 

</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;
        }
    }

}