Android 安卓:我的后退按钮有问题
我正在android上创建一个应用程序,当我选择“下一步”按钮以显示新图像,选择“上一步”按钮以显示上一个图像时,可以通过声音查看图像,但当按下“下一步”按钮至最大索引时,我希望它显示从第一个图像索引开始,当按下“上一步”按钮至最小索引时,我希望它显示从最大图像索引开始。当我单击“上一步”按钮转到0索引时出现问题,我希望它显示最终索引中的图像,当我单击“下一步”按钮转到最终索引时,我希望它显示最终索引中的图像但当我单击“后退”按钮时,什么也不会发生,所以我要如何使用“后退”按钮Android 安卓:我的后退按钮有问题,android,Android,我正在android上创建一个应用程序,当我选择“下一步”按钮以显示新图像,选择“上一步”按钮以显示上一个图像时,可以通过声音查看图像,但当按下“下一步”按钮至最大索引时,我希望它显示从第一个图像索引开始,当按下“上一步”按钮至最小索引时,我希望它显示从最大图像索引开始。当我单击“上一步”按钮转到0索引时出现问题,我希望它显示最终索引中的图像,当我单击“下一步”按钮转到最终索引时,我希望它显示最终索引中的图像但当我单击“后退”按钮时,什么也不会发生,所以我要如何使用“后退”按钮 public
public void btn_click(View v){
if (v == btn_next){
if((IMAGE_IDS.length)> currentimageindex){
try{
imageview.setImageResource(IMAGE_IDS[currentimageindex]);
mp = MediaPlayer.create(this, myMusic[currentsoundindex]);
mp.start();
currentimageindex = (currentimageindex + 1) % IMAGE_IDS.length;
currentsoundindex = (currentsoundindex + 1) % myMusic.length;
}
catch(Exception e){
Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
if((IMAGE_IDS.length)== currentimageindex){
try{
imageview.setImageResource(IMAGE_IDS[currentimageindex=0]);
mp = MediaPlayer.create(this, myMusic[currentsoundindex=0]);
mp.start();
currentimageindex = (currentimageindex + 1) % IMAGE_IDS.length;
currentsoundindex = (currentsoundindex + 1) % myMusic.length;
}
catch(Exception e){
Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
if (v == btn_back) {
if(currentimageindex!=0){
try{
imageview.setImageResource(IMAGE_IDS[currentimageindex]);
mp = MediaPlayer.create(this, myMusic[currentsoundindex]);
mp.start();
currentimageindex = (currentimageindex + IMAGE_IDS.length -1) % IMAGE_IDS.length;
currentsoundindex = (currentsoundindex + myMusic.length -1) % myMusic.length;
}
catch(Exception e){
Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
if((currentimageindex)==0){
try{
imageview.setImageResource(IMAGE_IDS[currentimageindex]);
mp = MediaPlayer.create(this, myMusic[currentsoundindex]);
mp.start();
currentimageindex = (currentimageindex + IMAGE_IDS.length -1) % IMAGE_IDS.length;
currentsoundindex = (currentsoundindex + myMusic.length -1) % myMusic.length;
}
catch(Exception e){
Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
}
如果我们缩进正确,我们得到这个
public void btn\u点击(视图五){
如果(v==btn\u下一步){
if((图像ID.length)>currentimageindex){
试一试{
setImageResource(IMAGE_id[currentimageindex]);
mp=MediaPlayer.create(这是myMusic[currentsoundindex]);
mp.start();
currentimageindex=(currentimageindex+1)%IMAGE\u id.length;
currentsoundindex=(currentsoundindex+1)%myMusic.length;
}捕获(例外e){
Toast.makeText(getBaseContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
}
}
如果((图像ID.length)=currentimageindex){
试一试{
setImageResource(IMAGE_id[currentimageindex=0]);
mp=MediaPlayer.create(这是myMusic[currentsoundindex=0]);
mp.start();
currentimageindex=(currentimageindex+1)%IMAGE\u id.length;
currentsoundindex=(currentsoundindex+1)%myMusic.length;
}捕获(例外e){
Toast.makeText(getBaseContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
}
}
如果(v==btn\u-back){
如果(currentimageindex!=0){
试一试{
setImageResource(IMAGE_id[currentimageindex]);
mp=MediaPlayer.create(这是myMusic[currentsoundindex]);
mp.start();
currentimageindex=(currentimageindex+IMAGE_id.length-1)%IMAGE_id.length;
currentsoundindex=(currentsoundindex+myMusic.length-1)%myMusic.length;
}捕获(例外e){
Toast.makeText(getBaseContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
}
}
如果((currentimageindex)==0){
试一试{
setImageResource(IMAGE_id[currentimageindex]);
mp=MediaPlayer.create(这是myMusic[currentsoundindex]);
mp.start();
currentimageindex=(currentimageindex+IMAGE_id.length-1)%IMAGE_id.length;
currentsoundindex=(currentsoundindex+myMusic.length-1)%myMusic.length;
}捕获(例外e){
Toast.makeText(getBaseContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
}
}
}
看起来您正在检查您的v==btn\u next
语句中是否有v==btn\u back
。您需要关闭v==btn\u next
语句,如下所示:
public void btn\u点击(视图五){
如果(v==btn\u下一步){
if((图像ID.length)>currentimageindex){
试一试{
setImageResource(IMAGE_id[currentimageindex]);
mp=MediaPlayer.create(这是myMusic[currentsoundindex]);
mp.start();
currentimageindex=(currentimageindex+1)%IMAGE\u id.length;
currentsoundindex=(currentsoundindex+1)%myMusic.length;
}捕获(例外e){
Toast.makeText(getBaseContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
}
}
如果((图像ID.length)=currentimageindex){
试一试{
setImageResource(IMAGE_id[currentimageindex=0]);
mp=MediaPlayer.create(这是myMusic[currentsoundindex=0]);
mp.start();
currentimageindex=(currentimageindex+1)%IMAGE\u id.length;
currentsoundindex=(currentsoundindex+1)%myMusic.length;
}捕获(例外e){
Toast.makeText(getBaseContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
}
}
}
如果(v==btn\u-back){
如果(currentimageindex!=0){
试一试{
setImageResource(IMAGE_id[currentimageindex]);
mp=MediaPlayer.create(这是myMusic[currentsoundindex]);
mp.start();
currentimageindex=(currentimageindex+IMAGE_id.length-1)%IMAGE_id.length;
currentsoundindex=(currentsoundindex+myMusic.length-1)%myMusic.length;
}捕获(例外e){
Toast.makeText(getBaseContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
}
}
如果((currentimageindex)==0){
试一试{
setImageResource(IMAGE_id[currentimageindex]);
mp=MediaPlayer.create(这是myMusic[currentsoundindex]);
mp.start();
currentimageindex=(currentimageindex+IMAGE_id.length-1)%IMAGE_id.length;
currentsoundindex=(currentsoundi