Android五六周作业
1.返回键实现对话框弹出是否退出应用程序
<LinearLayout 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:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".MainActivity" > <TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/hello_world" /> <Button android:id="@+id/btn_1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="click1" android:text="按钮1" /> <Button android:id="@+id/btn_2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignRight="@+id/textView1" android:layout_below="@+id/textView1" android:layout_marginTop="42dp" android:text="按钮2" /> </LinearLayout>
package com.example.a; import android.os.Bundle; import android.app.Activity; import android.app.AlertDialog; import android.content.DialogInterface; import android.view.Menu; import android.view.View; import android.widget.Button; import android.widget.Toast; @SuppressWarnings("unused") public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Button btn2 = (Button) findViewById(R.id.btn_2); btn2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Toast.makeText(MainActivity.this, "按钮2被点击", 0).show(); } }); } public void click1(View v) { Toast.makeText(this, "按钮1被点击", 0).show(); } public void onBackPressed() { AlertDialog dialog; AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setIcon(R.drawable.ic_launcher); builder.setTitle("普通对话框"); builder.setMessage("是否退出应用程序？"); builder.setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); MainActivity.this.finish(); } }); builder.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
<?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="单选对话框" android:layout_marginTop="10dp" android:textSize="20sp" android:textColor="#FFFDB371"/> <Button android:id="@+id/bt" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="男" android:layout_marginTop="20dp" android:layout_gravity="center"/> <Button android:id="@+id/bt2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="女" android:layout_marginTop="20dp" android:layout_gravity="center"/> </LinearLayout>
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; import android.widget.Toast; public class Demo4Activity 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_demo4); 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(Demo4Activity.this, "你选择的性别是男", Toast.LENGTH_SHORT).show(); }else{ Toast.makeText(Demo4Activity.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"?> <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=".Demo5Activity" android:orientation="vertical" android:background="#DFAF00"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="1.TextView显示文本信息" android:textColor="#0190FD" android:textSize="25dp" android:layout_gravity="center" android:layout_marginTop="20dp" android:textStyle="italic"/> <Button android:layout_width="350dp" android:layout_height="wrap_content" android:text="2.按钮" android:textColor="#0190FD" android:layout_gravity="center"/> <EditText android:layout_width="350dp" android:layout_height="wrap_content" android:hint="3.编辑框：请输入信息" android:textColorHint="#F80101" android:layout_gravity="center"/> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <RadioButton android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="4.男" android:textColor="#FF0000" android:layout_marginLeft="25dp"/> <RadioButton android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="5.女" android:textColor="#FF0000"/> </LinearLayout> <CheckBox android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="电脑" android:textColor="#FF0000" android:layout_marginLeft="25dp"/> <CheckBox android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="手机" android:textColor="#FF0000" android:layout_marginLeft="25dp"/> </LinearLayout>
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:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".Demo6Activity" android:orientation="vertical"> <TextView android:layout_width="wrap_content" android:layout_height="45dp" android:text="购物商城" 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"/> </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="#FF8F03" 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="#38EE74" android:layout_below="@id/title" android:layout_toRightOf="@id/tv_price" android:layout_marginTop="10dp"/> </RelativeLayout> </RelativeLayout>
package com.example.myapplication; 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 Demo6Activity 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}; @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity_demo6); mListView=(ListView) findViewById(R.id.lv); MyBaseAdapter mAdapter=new MyBaseAdapter(); mListView.setAdapter(mAdapter); } class MyBaseAdapter extends BaseAdapter{ public int getCount(){ return titles.length; } public Object getItem(int position){ return titles[position]; } public long getItemId(int position){ return position; } public View getView(int position, View convertView, ViewGroup parent){ View view=View.inflate(Demo6Activity.this,R.layout.list_item,null); TextView title=view.findViewById(R.id.title); TextView price=view.findViewById(R.id.price); ImageView iv=view.findViewById(R.id.iv); title.setText(titles[position]); price.setText(prices[position]); iv.setBackgroundResource(icons[position]); return view; } } }
