现在，我只想在用户访问应用程序时显示某种电池状态指示。例如，如果设备已插入，则设备应显示正在充电和电量。如果设备已拔出，则不应显示任何内容。如果设备未充电且电池电量不足，则应显示电池电量不足指示。
我已经设置了大部分代码，但问题是，例如，如果我运行应用程序并且设备已插入，屏幕上会显示充电指示。如果我拔下设备，充电将不再可见，但如果我重新插入设备，充电仍将不再可见。当设备插入或拔出、电池电量高或低时，电池警报应始终显示。应始终显示信息的变化。
这是我的广播接收器:
private BroadcastReceiver mBatInfoReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context arg0, Intent intent) {
//Battery level
int level = intent.getIntExtra("level", 0);
//Plugged in Status
int plugged = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
//Battery Status
int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
//If the device is charging or contains a full status, it's charging
boolean isCharging = status == BatteryManager.BATTERY_STATUS_CHARGING ||
status == BatteryManager.BATTERY_STATUS_FULL;
//If the device isCharging and plugged in, then show that the battery is charging
TextView batteryTextView = ((TextView) findViewById(R.id.charging));
TextView batteryLowTextView = ((TextView) findViewById(R.id.low_battery));
ImageView batteryLowImageView= ((ImageView) findViewById(R.id.low_battery_icon));
ImageView batteryImageView =((ImageView) findViewById(R.id.charging_battery_icon));
if (isCharging && plugged == BatteryManager.BATTERY_PLUGGED_AC || plugged == BatteryManager.BATTERY_PLUGGED_USB) {
//Gets the 'last synced' string and sets to datetime of the last sync
Resources resources = context.getResources();
String chargingString = String.format(resources.getString(R.string.charging), level);
//Dynamically sets the value of the battery level
batteryLowTextView.setVisibility(TextView.INVISIBLE);
batteryLowImageView.setVisibility(ImageView.INVISIBLE);
batteryTextView.setText(chargingString + "%");
} else if (level < LOW_BATTERY_LEVEL && !isCharging) {
Resources resources = context.getResources();
String lowBatteryString = String.format(resources.getString(R.string.low_battery));
batteryTextView.setVisibility(TextView.INVISIBLE);
batteryImageView.setVisibility(ImageView.INVISIBLE);
batteryLowTextView.setText(lowBatteryString);
} else if (!isCharging && level > LOW_BATTERY_LEVEL) {
//do nothing
batteryTextView.setVisibility(TextView.GONE);
batteryImageView.setVisibility(ImageView.GONE);
}
}
};
在我的 OnCreate 方法中，我调用
//calls registerReceiver to receive the broadcast for the state of battery
this.registerReceiver(this.mBatInfoReceiver,new
IntentFilter(Intent.ACTION_BATTERY_CHANGED));
所以，我想知道我做错了什么？是 boolean 人吗？
最佳答案
- 您的
if-then-else逻辑有很多漏洞(并且有@Vikram 提到的问题)。这可能导致接收者最终什么都不做。尝试简化逻辑以消除所有漏洞。 - 更新 TextView 时，还必须记住首先使其(及其 ImageView )可见。
这是您的 if-then-else 逻辑的替代品:
if (isCharging) {
//Gets the 'last synced' string and sets to datetime of the last sync
Resources resources = context.getResources();
String chargingString = String.format(resources.getString(R.string.charging), level);
//Dynamically sets the value of the battery level
batteryLowTextView.setVisibility(TextView.INVISIBLE);
batteryLowImageView.setVisibility(ImageView.INVISIBLE);
batteryTextView.setText(chargingString + "%");
batteryTextView.setVisibility(TextView.VISIBLE);
batteryImageView.setVisibility(ImageView.VISIBLE);
} else if (level <= LOW_BATTERY_LEVEL) {
Resources resources = context.getResources();
String lowBatteryString = String.format(resources.getString(R.string.low_battery));
batteryTextView.setVisibility(TextView.INVISIBLE);
batteryImageView.setVisibility(ImageView.INVISIBLE);
batteryLowTextView.setText(lowBatteryString);
batteryLowTextView.setVisibility(TextView.VISIBLE);
batteryLowImageView.setVisibility(ImageView.VISIBLE);
} else {
//show nothing
batteryTextView.setVisibility(TextView.GONE);
batteryImageView.setVisibility(ImageView.GONE);
batteryLowTextView.setVisibility(TextView.GONE);
batteryLowImageView.setVisibility(ImageView.GONE);
}
关于java - 如何设置始终显示的警报？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/26100101/