Android_ImageView simply implements image flipping

 

 

 renderings

 

1 ) You can store the id of the image in the array and use the setImageResource() or setImageDrawable() method ( put it in the array for easy looping )

2) When it is already the first image, click "Previous Page" again, and Toast prompts : it is already the first image , and will not turn forward; similarly, when it is already the last image, click "Next Page" again. One page", should be prompted by Toast : it is the last image , and will not turn back .

 

 give source code

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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:orientation="horizontal"
    tools:context="com.example.asus.a161304049_gary03.MainActivity">


    <LinearLayout
        android:id="@+id/Layoutt"
        android:layout_width="match_parent"
        android:layout_height="215dp"
        android:orientation="vertical">

        <ImageView
            android:id="@+id/imagexianshi"
            android:layout_width="match_parent"
            android:layout_height="180dp"
            app:srcCompat="@drawable/qzu1" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal">

            <Button
                android:id="@+id/Back"
                android:layout_width="100dp"
                android:layout_height="wrap_content"
                android:gravity="center"
                android:text="上一张" />

            <Button
                android:id="@+id/Next"
                android:layout_width="100dp"
                android:layout_height="wrap_content"
                android:text="下一张" />
        </LinearLayout>

    </LinearLayout>

</FrameLayout>

activity_main.xml

 

package com.example.asus.a161304049_gary03;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.Button;
import  android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    // Use an array to store images 
       int [] images = new  int []{
            R.drawable.qzu1,
            R.drawable.qzu2,
            R.drawable.qzu3,
            R.drawable.qzu5
    };
    // As the subscript of the picture 
    int countImg = 0 ;
     // Forward and backward buttons 
    private Button B1,B2;
     // Use ImageView to store pictures 
    private ImageView Xianshi;
    @Override
    protected  void onCreate (Bundle savedInstanceState) {
         super .onCreate (savedInstanceState);
        setContentView(R.layout.activity_main);

        B1 = (Button) findViewById(R.id.Back);
        B2 = (Button) findViewById(R.id.Next);
        Xianshi = (ImageView) findViewById(R.id.imagexianshi);

        Xianshi.setImageResource(images[ 0 ]);

        B1.setOnClickListener( new Button.OnClickListener() {
             public  void onClick(View v) {
                 // Here is a simple logic
                 // If the selected picture is the first one, then the previous one cannot be selected. Output Toast prompt message 
                if (countImg>0 ){
                    countImg -- ;
                     // Use setImageResource to display pictures 
                    Xianshi.setImageResource(images[countImg]);
                }else{
                    Toast.makeText(MainActivity.this , "Already the first image, and will not turn forward" ,Toast.LENGTH_SHORT).show();
                }
            }
        });

        B2.setOnClickListener( new Button.OnClickListener() {
             public  void onClick(View v) {
                 // If the selected picture is the last one, then you can't select the next one. Output the message of Toast prompt 
                if (countImg<3 ){
                    countImg++;
                    Xianshi.setImageResource(images[countImg]);
                }else{
                    Toast.makeText(MainActivity.this , "It is the last image, and will not turn back" ,Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}

MainActivity

 

 

The ImageView control is used to store pictures and display them. The xml attribute is not the focus of this article, so it will not be introduced here.

 

Step 1: Define member variables

    // Use an array to store images 
       int [] images = new  int []{
            R.drawable.qzu1,
            R.drawable.qzu2,
            R.drawable.qzu3,
            R.drawable.qzu5
    };
    // As the subscript of the picture 
    int countImg = 0 ;
     // Forward and backward buttons 
    private Button B1,B2;
     // Use ImageView to store pictures 
    private ImageView Xianshi;

 

 

Step 2: Implement the event response mechanism for buttons "previous" and "next"

 protected  void onCreate (Bundle savedInstanceState) {
         super .onCreate (savedInstanceState);
        setContentView(R.layout.activity_main);

        B1 = (Button) findViewById(R.id.Back);
        B2 = (Button) findViewById(R.id.Next);
        Xianshi = (ImageView) findViewById(R.id.imagexianshi);

        Xianshi.setImageResource(images[ 0 ]);

        B1.setOnClickListener( new Button.OnClickListener() {
             public  void onClick(View v) {
                 // Here is a simple logic
                 // If the selected picture is the first one, then the previous one cannot be selected. Output Toast prompt message 
                if (countImg>0 ){
                    countImg -- ;
                     // Use setImageResource to display pictures 
                    Xianshi.setImageResource(images[countImg]);
                }else{
                    Toast.makeText(MainActivity.this , "Already the first image, and will not turn forward" ,Toast.LENGTH_SHORT).show();
                }
            }
        });

        B2.setOnClickListener( new Button.OnClickListener() {
             public  void onClick(View v) {
                 // If the selected picture is the last one, then you can't select the next one. Output the message of Toast prompt 
                if (countImg<3 ){
                    countImg++;
                    Xianshi.setImageResource(images[countImg]);
                }else{
                    Toast.makeText(MainActivity.this , "It is the last image, and will not turn back" ,Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

 

Portal: Several common uses of message mode Toast.make Text