Android ImageView功能的实现

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 }