【发布时间】：2018-12-24 04:33:35
【问题描述】：
我正在尝试用AsyncTask 和CountDownTimer 更新ProgressBar。我没有错误，但ProgressBar 没有更新。
由于MyDownloadTask 扩展AsyncTask 我不需要发布方法或onProgressUpdate()。我的 ProgressBar 在 doInBackground() 中自动更新。
我认为CountDownTimer中的代码没有执行，但我调用的是monCountTimer.start();
这是我的 Java 代码：
public class myDownloadTask extends AsyncTask<Integer, Integer, String> {
public void setMonCountTimer(CountDownTimer monCountTimer) {
this.monCountTimer = monCountTimer;
}
public void setInc(int inc) {
this.inc = inc;
}
public void setMaProgressBar(ProgressBar maProgressBar) {
this.maProgressBar = maProgressBar;
}
public CountDownTimer getMonCountTimer() {
return monCountTimer;
}
public int getInc() {
return inc;
}
public ProgressBar getMaProgressBar() {
return maProgressBar;
}
protected CountDownTimer monCountTimer;
private int inc = 0;
protected ProgressBar maProgressBar;
public void setMonAct(MainActivity monAct) {
this.monAct = monAct;
}
public MainActivity getMonAct() {
return monAct;
}
private MainActivity monAct;
public myDownloadTask(ProgressBar maBarre, MainActivity monActi) {
this.maProgressBar = maBarre;
this.monAct = monActi;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
this.maProgressBar.setProgress(0);
}
@Override
protected void onProgressUpdate(Integer... integers) {
super.onProgressUpdate(integers);
}
@Override
protected String doInBackground(Integer... integers) {
Thread monThread = new Thread(new Runnable() {
@Override
public void run() {
monCountTimer = new CountDownTimer(6000, 1000) {
@Override
public void onTick(long millisUntilFinished) {
myDownloadTask.this.inc++;
myDownloadTask.this.getMaProgressBar().setProgress((int) myDownloadTask.this.inc* 100 / (6000 / 1000));
}
@Override
public void onFinish() {
}
};
monCountTimer.start();
}
});
return "coucou";
}
}
主类：
public class MainActivity extends AppCompatActivity {
private ProgressBar maBarre ;
public void setMaBarre(ProgressBar maBarre) {
this.maBarre = maBarre;
}
public void setLaunchAsync(Button launchAsync) {
this.launchAsync = launchAsync;
}
public void setMonHandler(Handler monHandler) {
this.monHandler = monHandler;
}
public void setMonCountTimer(CountDownTimer monCountTimer) {
this.monCountTimer = monCountTimer;
}
public void setMonTask(myDownloadTask monTask) {
this.monTask = monTask;
}
public void setProgressThread(Thread progressThread) {
ProgressThread = progressThread;
}
public void setI(int i) {
this.i = i;
}
public ProgressBar getMaBarre() {
return maBarre;
}
public Button getLaunchAsync() {
return launchAsync;
}
public Handler getMonHandler() {
return monHandler;
}
public CountDownTimer getMonCountTimer() {
return monCountTimer;
}
public String getPROGRESS_BAR_INCREMENT() {
return PROGRESS_BAR_INCREMENT;
}
public static int getMessagePreExecute() {
return MESSAGE_PRE_EXECUTE;
}
public static int getMessageProgressUpdate() {
return MESSAGE_PROGRESS_UPDATE;
}
public static int getMessagePostExecute() {
return MESSAGE_POST_EXECUTE;
}
public myDownloadTask getMonTask() {
return monTask;
}
public Thread getProgressThread() {
return ProgressThread;
}
public int getI() {
return i;
}
private Button launchAsync;
private Handler monHandler ;
private CountDownTimer monCountTimer ;
private final String PROGRESS_BAR_INCREMENT="ProgreesBarIncrementId";
private static final int MESSAGE_PRE_EXECUTE = 1;
private static final int MESSAGE_PROGRESS_UPDATE = 2;
private static final int MESSAGE_POST_EXECUTE = 3;
myDownloadTask monTask;
Thread ProgressThread ;
private int i = 0 ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
maBarre = (ProgressBar) findViewById(R.id.progressBar);
launchAsync = (Button) findViewById(R.id.button);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
this.launchAsync.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
monTask = new myDownloadTask(MainActivity.this.maBarre , MainActivity.this);
monTask.execute();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onPointerCaptureChanged(boolean hasCapture) {
}
}
你能帮帮我吗？
【问题讨论】：
-
嗨。我会尽力提供帮助。最好对可能出现的问题提供更多分析。此外，最好发布 xml 布局。但首先要做的是将问题分成两半。是演示文稿问题吗？还是更新进度条的逻辑有问题？例如，如果将“maBarre.setProgress(50)”添加到 onCreate，进度条会出现在屏幕上吗？
-
好的。最好使用任何附加信息编辑原始问题。在找到解决方案之前，请勿将其发布在答案中。如果您在答案中发布代码，那么您将被否决，这将降低获得有用响应的可能性，因为较少人看到被否决的问题。你按照我的建议做了吗？尝试在 onCreate 中调用 setProgress(50) 以验证进度是否出现在屏幕上？如果没有出现，则很可能是布局问题。
标签： java android android-asynctask android-progressbar countdowntimer