[英]How to stop async task executions when back button is pressed
Please i have an activity that contains async task method, This async task method continues to execute in background even when the user has moved from that page. 请我有一个包含异步任务方法的活动,即使用户已从该页面移动,此异步任务方法也会继续在后台执行。 Please is there a way to stop async task executions as soon as a user press on the back button or move from that page to another page. 只要用户按下后退按钮或从该页面移动到另一页面,就有办法停止异步任务执行。
Below is what i have tried but it isnt working 以下是我尝试过但它不起作用
private AsyncTask totalLikesAsync;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity);
context = this;
totalLikesAsync = new TotalLikes().execute(msgID);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem menuItem) {
switch (menuItem.getItemId()) {
case android.R.id.home:
totalLikesAsync.cancel(true);
this.finish();
break;
case R.id.share:
new ShareImage().execute(msgImage);
default:
return super.onOptionsItemSelected(menuItem);
}
return true;
}
private class TotalLikes extends AsyncTask<String, String, JSONObject> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected JSONObject doInBackground(String... msgIDs) {
UserFunctions userFunction = new UserFunctions();
String msgsID = msgIDs[0];
JSONObject json=null;
if(!isCancelled()){
//This gets all the information unread from the server
json = userFunction.TotalLikes(context, msgsID);
}
return json;
}
@Override
protected void onPostExecute(JSONObject json) {
/**
* Checks for success message.
**/
if (json != null) {
...
} else {
...
}
}
}
UPDATE UPDATE
After testing all the answers below, they all allow the execution of doinbackground
within the async task even though the back button is pressed. 在测试下面的所有答案后,即使按下后退按钮,它们都允许在异步任务中执行doinbackground
。 I want a situation where the Background would be cancelled as soon as back button is pressed. 我想要一个按下后退按钮后取消背景的情况。
@Override
public void onBackPressed() {
super.onBackPressed();
if (totalLikesAsync != null && totalLikesAsync.getStatus().equals(AsyncTask.Status.RUNNING)) {
totalLikesAsync.cancel(true);
}
}
@Override
public void onBackPressed() {
super.onBackPressed();
totalLikesAsync.cancel(true);
}
@Override
public void onBackPressed() {
TotalLikes.cancel(true);
// If you want to finish the activity you can use below code
// finish();
super.onBackPressed();
}
handle yourself the onBackPressed() method: 自己处理onBackPressed()方法:
@Override
public void onBackPressed()
{
if (totalLikesAsync != null)
totalLikesAsync.cancel(true);
super.onBackPressed();
}
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