一、首先實現界面部分
代碼:
<?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">
<ImageView
android:id="@+id/photo"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="@drawable/a1"/>
</RelativeLayout>
界面部分只用到了一個ImageView。
二、實現圖片的切換
package com.liu.photoslide;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.widget.ImageView;
public class MainActivity extends AppCompatActivity {
//定義ImageView對象
private ImageView iv;
//圖片的下標
private int count = 0;
//定義手勢監聽對象
private GestureDetector gd;
//定義圖片數組,這裏我就用到了兩張圖片a1.jpg,a2.jpg
private int[] photoIndex = new int[]{
R.drawable.a1,R.drawable.a2
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//獲取圖片id
iv = findViewById(R.id.photo);
//OnGestureListener處理手勢監聽
gd = new GestureDetector(this,OnGestureListener);
}
//當此Activity被觸摸時回調,這裏用到了觸摸回調:onTouchEvent
//按下回調是:onKeyDown,擡起回調:onKeyUp
public boolean onTouchEvent(MotionEvent event) {
gd.onTouchEvent(event);
//必須是true
return true;
}
/**
*自定義GestureDetector的手勢識別監聽器
*/
private GestureDetector.OnGestureListener OnGestureListener = new GestureDetector.SimpleOnGestureListener(){
//滑屏:用戶按下觸摸屏、快速移動後鬆開.識別是滑屏後回調onFling方法
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
//獲取手指觸碰座標,計算是向左滑還是向右滑
float x = e2.getX()-e1.getX();
if(x>0){
count ++;
count = count%(photoIndex.length);
}else if(x<0){
count --;
count = (count+(photoIndex.length))%(photoIndex.length);
}
//切換圖片
iv.setImageResource(photoIndex[count]);
return true;
}
};
}
三、實現效果
效果還不錯,但看着很僵硬,,,。