例题2-13
activity_main.xml
1 <?xml version="1.0" encoding="utf-8"?> 2 <!--suppress ALL --> 3 <LinearLayout xmlns:app="http://schemas.android.com/apk/res-auto" 4 android:layout_width="fill_parent" 5 android:layout_height="fill_parent" 6 android:orientation="vertical" 7 android:gravity="center" 8 xmlns:android="http://schemas.android.com/apk/res/android"> 9 <LinearLayout 10 android:layout_width="wrap_content" 11 android:layout_height="wrap_content"> 12 13 <ImageView android:id="@+id/image" 14 android:layout_width="355dip" 15 android:layout_height="650dip" 16 android:src="@drawable/p2"/> 17 </LinearLayout> 18 <LinearLayout 19 android:layout_width="match_parent" 20 android:layout_height="fill_parent"> 21 <Button android:id="@+id/up" 22 android:layout_width="150dip" 23 android:layout_height="wrap_content" 24 android:text="上一张"/> 25 <Button android:id="@+id/down" 26 android:layout_width="150dip" 27 android:layout_height="wrap_content" 28 android:text="下一张"/> 29 </LinearLayout> 30 </LinearLayout>
Mainactivity.java代码
1 package com.example.hello; 2 3 import androidx.appcompat.app.AppCompatActivity; 4 5 import android.os.Bundle; 6 import android.telephony.SmsManager; 7 import android.view.View; 8 import android.widget.Button; 9 import android.widget.CheckBox; 10 import android.widget.ImageView; 11 import android.widget.ProgressBar; 12 import android.widget.RadioButton; 13 import android.widget.TextView; 14 15 public class MainActivity extends AppCompatActivity { 16 Button Button1,Button2; 17 int[] images={ 18 R.drawable.p2, R.drawable.p3, R.drawable.p4, R.drawable.p5, 19 R.drawable.p6, R.drawable.p7, R.drawable.p8, R.drawable.p9, 20 R.drawable.p10, R.drawable.p11, R.drawable.p12, R.drawable.p1 21 }; 22 ImageView image; 23 int index=0; 24 @Override 25 protected void onCreate(Bundle savedInstanceState) { 26 super.onCreate(savedInstanceState); 27 setContentView(R.layout.activity_main); 28 Button1 = (Button)findViewById(R.id.up); 29 Button2 = (Button)findViewById(R.id.down); 30 image = (ImageView)findViewById(R.id.image); 31 Button1.setOnClickListener(new mclik()); 32 Button2.setOnClickListener(new mclik()); 33 } 34 35 class mclik implements View.OnClickListener{ 36 37 @Override 38 public void onClick(View v) { 39 if(v==Button1){ 40 if(index>0&&index<images.length){ 41 index--; 42 image.setImageResource(images[index]); 43 }else { 44 index=images.length-1; 45 image.setImageResource(images[index]); 46 } 47 } 48 if(v==Button2){ 49 if(index>=0&&index<images.length-1){ 50 index++; 51 image.setImageResource(images[index]); 52 }else { 53 index=0; 54 image.setImageResource(images[index]); 55 } 56 } 57 } 58 } 59 60 }