第五、六周作业
package com.example.homework;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.KeyEvent;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
switch (keyCode) {
case KeyEvent.KEYCODE_BACK:
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setIcon(R.mipmap.ic_launcher);
builder.setTitle("提示！");
builder.setMessage("确认退出程序？");
builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
finish();
}
})
.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
})
.show();
break;
}
return false;
}
}
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
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="@+id/tv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="请选择性别"
android:layout_marginTop="10dp"
android:textSize="30sp"
android:textColor="#000000"/>
<Button
android:id="@+id/bt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="开始选择"
android:layout_marginTop="20dp"
android:layout_gravity="center"/>
</LinearLayout>
package com.example.homework;
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;
import android.widget.Toast;
public class Main2Activity extends AppCompatActivity implements View.OnClickListener {
private String[] sexArry={"男","女"};
private int sex=0;
private TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
findViewById(R.id.bt).setOnClickListener(this);
}
@Override
public void onClick(View view) {
AlertDialog dialog;
AlertDialog.Builder builder=new AlertDialog.Builder(this)
.setTitle("选择你的性别")
.setSingleChoiceItems(new String[]{"男", "女"},sex, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int i) {
sex=i;
}
})
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int i) {
dialog.dismiss();
if (sex==0){
Toast.makeText(Main2Activity.this, "你选择的性别是男", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(Main2Activity.this, "你选择的性别是女", Toast.LENGTH_SHORT).show();
}
}
})
.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="#FAFAFA">
<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="#000000"
/>
<Button
android:layout_width="match_parent"
android:layout_height="60dp"
android:text="2.按钮"
android:textSize="25sp"
android:layout_marginLeft="20dp"
android:layout_marginRight="20dp"
android:layout_marginTop="90dp"
android:textColor="#000000"/>
<EditText
android:layout_width="match_parent"
android:layout_height="60dp"
android:text="3.编辑框：请输入信息"
android:textSize="20sp"
android:layout_marginLeft="20dp"
android:layout_marginRight="20dp"
android:layout_marginTop="180dp"
android:textColor="#80000000"/>
<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="#2196F3"
android:layout_marginTop="250dp"/>
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="女"
android:textSize="30sp"
android:textColor="#2196F3"
android:layout_marginTop="250dp"
/>
</RadioGroup>
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="电脑"
android:textColor="#2196F3"
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="#2196F3"
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"
tools:context=".MainActivity"
android:orientation="vertical">
<TextView
android:id="@+id/tv_1"
android:layout_width="match_parent"
android:layout_height="45dp"
android:text="购物商城"
android:textSize="18sp"
android:textColor="#000000"
android:background="#FAFAFA"
android:gravity="center"/>
<ListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
<?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="16dp">
<ImageView
android:id="@+id/iv"
android:layout_width="120dp"
android:layout_height="90dp"
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="20sp"
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="20sp"
android:textColor="#F44336"
android:layout_marginTop="10dp"
android:layout_below="@id/title"/>
<TextView
android:id="@+id/price"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="1000"
android:textSize="20sp"
android:textColor="#2196F3"
android:layout_below="@id/title"
android:layout_toRightOf="@id/tv_price"
android:layout_marginTop="10dp"/>
</RelativeLayout>
</RelativeLayout>
package com.example.homework;
import android.app.Activity;
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 Main4Activity extends Activity {
private ListView mListView;
private String [] titles={"桌子","苹果","蛋糕","线衣","猕猴桃","围巾"};
private String [] prices={"1800","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};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main4);
mListView=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(Main4Activity.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;
}
}
}
浙公网安备 33010602011771号