这是我的代码：
public class MainActivity extends Activity {
private NotificationManager mNotifyManager;
private NotificationCompat.Builder mBuilder;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mNotifyManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
mBuilder = new NotificationCompat.Builder(this);
}
public void click(View view) {
noti();
}
private void noti() {
mBuilder.setContentTitle("Picture Download")
.setContentText("Download in progress")
.setSmallIcon(R.drawable.ic_launcher);
// Start a lengthy operation in a background thread
new Thread(
new Runnable() {
@Override
public void run() {
int incr;
// Do the "lengthy" operation 20 times
for (incr = 0; incr <= 100; incr+=5) {
// Sets the progress indicator to a max value, the
// current completion percentage, and "determinate"
// state
mBuilder.setProgress(100, incr, false);
// Displays the progress bar for the first time.
mNotifyManager.notify(0, mBuilder.build());
// Sleeps the thread, simulating an operation
// that takes time
try {
// Sleep for 5 seconds
Thread.sleep(1*1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
// When the loop is finished, updates the notification
mBuilder.setContentText("Download complete")
// Removes the progress bar
.setProgress(0,0,false);
mNotifyManager.notify(0, mBuilder.build());
}
}
// Starts the thread by calling the run() method in its Runnable
).start();
}
}
它在android 4.2.2设备上工作正常，但是当我试图在Android 2.2设备上运行它时，通知没有显示，我得到了以下日志：
RuntimeException in notify -
java.lang.Throwable: stack dump
at android.app.NotificationManager.notify(NotificationManager.java:118)
at android.app.NotificationManager.notify(NotificationManager.java:92)
at com.gyh.notitest.MainActivity$1.run(MainActivity.java:49)
at java.lang.Thread.run(Thread.java:1019)
谢谢！
答案 0 :(得分：1)
您是否尝试将v4.jar库导入项目？它支持在低api（例如Android 2.2）上运行的新api版本的功能。
干杯，
答案 1 :(得分：1)
没关系..
我将代码更改为：
public class MainActivity extends Activity {
private NotificationManager mNotifyManager;
private NotificationCompat.Builder mBuilder;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent resultIntent = new Intent(this, MainActivity.class);
PendingIntent resultPendingIntent =
PendingIntent.getActivity(
this,
0,
resultIntent,
PendingIntent.FLAG_UPDATE_CURRENT
);
mNotifyManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
mBuilder = new NotificationCompat.Builder(
getApplicationContext()).setSmallIcon(R.drawable.ic_launcher)
.setContentTitle("My notification")
.setContentText("Hello World!")
.setContentIntent(resultPendingIntent);
}
public void click(View view) {
noti();
}
private void noti() {
// Start a lengthy operation in a background thread
new Thread(
new Runnable() {
@Override
public void run() {
int incr;
// Do the "lengthy" operation 20 times
for (incr = 0; incr <= 100; incr+=5) {
// Sets the progress indicator to a max value, the
// current completion percentage, and "determinate"
// state
mBuilder.setProgress(100, incr, false);
// Displays the progress bar for the first time.
mNotifyManager.notify(0, mBuilder.build());
// Sleeps the thread, simulating an operation
// that takes time
try {
// Sleep for 5 seconds
Thread.sleep(1*1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
// When the loop is finished, updates the notification
mBuilder.setContentText("Download complete")
// Removes the progress bar
.setProgress(0,0,false);
mNotifyManager.notify(0, mBuilder.build());
}
}
// Starts the thread by calling the run() method in its Runnable
).start();
}
}
然后出现了通知，但没有进展T_T我无能为力......我现在能想到的唯一方法是带有进度条的自定义布局......
答案 2 :(得分：0)
我重新编写了您的代码以启用多个通知进度。还更新为可在android Oreo +上使用
class MainActivity : AppCompatActivity(){
private var mNotifyManager: NotificationManagerCompat? = null
private var mBuilder: NotificationCompat.Builder? = null
private var notificationId = 0
val CHANNEL_ID ="download_progress_notification"
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
mNotifyManager = NotificationManagerCompat.from(this)
mBuilder = NotificationCompat.Builder(this, CHANNEL_ID)
}
private fun noti(notficationId : Int) {
mBuilder?.setContentTitle("Picture Download")
?.setContentText("Download in progress")
?.setSmallIcon(R.mipmap.ic_launcher)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) { // you must create a notification channel for API 26 and Above
val name = "my channel2"
val description = "channel description2"
val importance = NotificationManager.IMPORTANCE_DEFAULT
val channel = NotificationChannel(CHANNEL_ID, name, importance);
channel.setDescription(description)
// Register the channel with the system; you can't change the importance
// or other notification behaviors after this
val notificationManager = getSystemService(NotificationManager::class.java)
notificationManager.createNotificationChannel(channel)
}
// Start a lengthy operation in a background thread
Thread(object : Runnable{
override fun run() {
var incr: Int
// Do the "lengthy" operation 20 times
incr = 0
while (incr <= 100) {
// Sets the progress indicator to a max value, the
// current completion percentage, and "determinate"
// state
mBuilder?.setProgress(100, incr, false)
// Displays the progress bar for the first time.
mNotifyManager?.notify(notficationId, mBuilder!!.build())
// Sleeps the thread, simulating an operation
// that takes time
try {
// Sleep for 5 seconds
Thread.sleep((1 * 1000).toLong())
} catch (e: InterruptedException) {
e.printStackTrace()
}
incr += 5
}
// When the loop is finished, updates the notification
mBuilder?.setContentText("Download complete")
// Removes the progress bar
?.setProgress(0, 0, false)
mNotifyManager?.notify(notficationId, mBuilder!!.build())
}
}).start()
}
override fun onOptionsItemSelected(item: MenuItem?): Boolean {
when (item?.itemId) {
R.id.menu_option -> {
noti(notificationId++)
return true
}
}
return super.onOptionsItemSelected(item)
}
}