onLocationChanged(Location loc) & 的问题Android 中的异步任务

发布于 2024-10-20 23:56:33 字数 996 浏览 5 评论 0原文

我有一个连接到互联网的 Android 应用程序，可以实时对纬度和经度坐标进行反向地理编码。这会延迟 UI，并可能导致它给出“未响应 - 强制关闭/等待”错误（如预期，不使用异步/线程处理程序！）

我已经实现了一个工作得很好的异步任务（不再有 UI 延迟！），但在 onLocationChanged 方法中设置的变量（将它们设置为纬度和经度）是无法访问的。我正在执行此操作的类链接到另一个单独的类，该类传递变量并可以向包含反向地理编码地址的人发送短信。但是，由于使用 doinbackground 方法实现异步任务，我无法再发送我需要的内容。我不知道是否可以更好地解释，我将提供示例代码。

public void onLocationChanged(Location loc){
    mylat = loc.getLatitude();
    mylong = loc.getLongitude();
}

/*
afaik, this is the code that does the internet stuff, that lags the 
UI.  If I put this in doinbackground, it cannot access mylat & my long, 
and the "loc.getLatitude" has to be done in the "onLocationChanged" 
method, which HAS to exist. If I leave the ListAddress code outside the 
doinbackground, everything works, BUT the UI will obviously lag.
*/
List<Address> addresses = geoCoder.getFromLocation(mylat,mylong, 1);

任何人都可以建议获取 mylat = loc.getLatitude(); 的最佳方法吗？ & mylat = loc.getLatitude(); 在 doinbackground 方法中？

原文

I have an android app that connects to the internet to do a reverse geocode on lat and long co-ordinates in real time. This lags the UI and can cause it to give a "not responding - force close/wait" error(as expected without using async/ threads-handlers!)

I have implemented an Async Task which works very well(no more UI lag!), but variables set inside the onLocationChanged method (that sets them to the latitude & longitude) are inaccessible.
The class I am doing this in, is linked to another seperate class that passes the variables and can send an sms to a person which includes the reverse-geocoded address.
However, since implementing the Async Task using the doinbackground method, I can no longer send what I need. I don't know if I can explain any better, I will provide sample code.

public void onLocationChanged(Location loc){
    mylat = loc.getLatitude();
    mylong = loc.getLongitude();
}

/*
afaik, this is the code that does the internet stuff, that lags the 
UI.  If I put this in doinbackground, it cannot access mylat & my long, 
and the "loc.getLatitude" has to be done in the "onLocationChanged" 
method, which HAS to exist. If I leave the ListAddress code outside the 
doinbackground, everything works, BUT the UI will obviously lag.
*/
List<Address> addresses = geoCoder.getFromLocation(mylat,mylong, 1);

Can anyone advise the best way to get mylat = loc.getLatitude(); & mylat = loc.getLatitude(); inside the doinbackground method?

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酷炫老祖宗 2024-10-27 23:56:33

重写 AsyncTask 的构造函数并将 mylat 和 mylong 设置为该类中的变量

或将它们直接传递给 doInBackground 方法。

... 扩展 AsyncTask {
    受保护的 ReturnType doInBackground(Double... params) {
        mylat = 参数[0];
        mylong = 参数[1];
        列表地址 = geoCoder.getFromLocation(mylat, mylong, 1);
        ...
    }
    ...
}

并使用execute(mylat, mylong);

调用它

Override the constructor of your AsyncTask and set mylat and mylong as variables in that class

or pass them to the doInBackground method directly.

... extends AsyncTask<Double, ProgressType, ReturnType> {
    protected ReturnType doInBackground(Double... params) {
        mylat = params[0];
        mylong = params[1];
        List addresses = geoCoder.getFromLocation(mylat, mylong, 1);
        ...
    }
    ...
}

and call it with execute(mylat, mylong);

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伴梦长久 2024-10-27 23:56:33

您可以重写 AsyncTask 类的构造函数，将 mylat 和 mylong 作为参数传递。在构造函数中，您将参数保存为 AsyncTask 的成员变量。这样做，您应该能够在 doInBackground() 方法中访问它们。

另一件事是，您应该考虑是否真的需要位置侦听器。也许 LocationManager 及其方法 getLastKnownLocation() 也可以完成这项工作，如果您只需要某些时刻的当前位置。然后您还可以在 doInBackground() 方法中确定当前位置。但请阅读 getLastKnownLocation( ）如果它确实符合您的需求。如果每次设备移动时都需要更新，则必须使用位置侦听器。