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;
}
}
}

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