非活动中的CursorLoader [英] CursorLoader in a Non Activity

问题描述

我有一个小项目，我从内容提供商那里读取诸如呼叫日志，短信日志等系统指标.

I have small project where I read system metrics like Calls Logs, SMS Logs etc from content providers.

我创建了(Call/SMS)Logger 类，以从内容提供者中读取并将信息保存在(Call/SMS)Metrics 类的对象中.

I have created (Call/SMS)Logger classes to read from content providers and save info in object of (Call/SMS)Metrics clases.

MainActivity 使用(Call/SMS)Metrics 类的对象中的信息，并使用databaseOpenHelper类将数据保存在我自己的数据库中.

The MainActivity uses the info in the objects of (Call/SMS)Metrics classes and saves the data in my own database using a databaseOpenHelper class.

现在，我打算使用CursorLoader从contentproviders中加载数据.

Now I intend to use CursorLoader to load datafrom contentproviders.

我看到的示例表明MainActivity实现了LoaderManager.LoaderCallbacks

The examples I have seen suggest that MainActivity implements LoaderManager.LoaderCallbacks

在非活动类上完成实际查询后，如何在我的项目中使用它?

我可以在Activity中创建1个loaderManger并将其用于每个非Activity吗?

以下是一些示例代码段:

Here is some sample code snippets:

在Main Activity中，我将数据称为集合，然后将上下文传递给clsss，以便他们可以在管理器游标中使用它

From Main Activity I call the collection of data, I pass the context to the clssess so that they can use it in manager cursor

private void CollectSystemMetrics() {
    //passing the context in constructor so that it can be passed to 
    //the non activity classes which need it for quering
    SystemMetricsCollector collector = new SystemMetricsCollector(this);        
    _callMetrics = collector.CollectCallMetrics();
    _smsMetrics = collector.CollectSMSMetrics();

    Toast toast = Toast.makeText(
            MyActivity.this,
            "Calls and SMS Data Collected",
            Toast.LENGTH_SHORT);
    toast.show();
} 

SystemMetricsCollector中的方法来提升SMSData

Method in SystemMetricsCollector to raed SMSData

public SMSMetrics CollectSMSMetrics() {
    SMSLogger smsLogger = new SMSLogger(_context);
    smsLogger.ReadSMSDataFromPhone();
    return smsLogger.GetSMSMetrics();
}

SMSLogger类中的变量.

Variables in SMSLogger class.

Uri smsUri = Uri.parse("content://sms");
String[] selectColumns = null;
String where = null;
String whereArgs[] = null;
String sortBy = null;

SMSLogger中使用光标读取数据的方法

Methods in SMSLogger to read data using cursor

public void ReadSMSDataFromPhone() {
    int inCount = 0, outCountContacts = 0, outCountUnknown = 0;
    Cursor managedCursor;
    managedCursor = _context.getContentResolver().query(
            smsUri,selectColumns,where,whereArgs,sortBy);
    try {
        if (managedCursor.moveToFirst()) {
            int idxAddress = managedCursor.getColumnIndexOrThrow("address");
            int idxType = managedCursor.getColumnIndex("type");
            do {
                int valType = managedCursor.getInt(idxType);
                switch (valType) {
                    case 2://outgoing
                        String valAddress = 
                        managedCursor.getString(idxAddress);
                        if (isContact(valAddress)) outCountContacts++;
                        else outCountUnknown++;
                        break;
                    default://incoming
                        inCount++;
                        break;
                }
            } while (managedCursor.moveToNext());
        }
    } finally {
        managedCursor.close();
    }//end finally
    _smsMetrics.set_receivedSMS(inCount);
    _smsMetrics.set_sentSMSContacts(outCountContacts);
    _smsMetrics.set_sentSMSUnknown(outCountUnknown);
}

推荐答案

当对非活动类进行实际查询时，如何在我的项目中使用它?

How can I use this in my project when actual query stuff is done on non activity classes?

使活动成为实际使用Loaders的活动，或者不使用Loaders.欢迎您在AsyncTask或Thread中使用ContentResolver.

Either have the activity be the one to actually use the Loaders, or do not use Loaders. You are welcome to use a ContentResolver in an AsyncTask or Thread instead.

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