Android API日历

Question

我正在使用Android4.1API创建一个android应用程序，但我对它有一个问题。

我的代码编译似乎有问题，虽然它没有给我任何错误，但当我试图在Android手机上运行它时，它确实崩溃了。

package com.example.meetingmute;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.provider.CalendarContract;
import android.provider.CalendarContract.Calendars;
import android.provider.CalendarContract.Events;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.database.Cursor;
import android.view.Menu;
import android.widget.Button;
import android.widget.TextView;
import android.view.View;
import android.view.View.OnClickListener;
import android.media.AudioManager;

public class MainActivity extends Activity {

Button button;
TextView text;
boolean ringeronoff;
AudioManager mAudioManager;
AlertDialog ad;


@Override
public void onCreate(Bundle savedInstanceState) {
    Context context = getApplicationContext();
    ContentResolver contentResolver =       getApplicationContext().getContentResolver();

    final Cursor cursor =  contentResolver.query(Uri.parse("content://calendar/calendars"),
            (new String[] { "_id", "displayName", "selected" }), null, null, null);

    while (cursor.moveToNext()) {

        final String _id = cursor.getString(0);
        final String displayName = cursor.getString(1);
        final Boolean selected = !cursor.getString(2).equals("0");

        System.out.println("Id: " + _id + " Display Name: " + displayName + " Selected: " + selected);
    }
    ad = new AlertDialog.Builder(this).create();
    read();

    Cursor cur = null;
    ContentResolver cr = getContentResolver();
    ContentValues values = new ContentValues();
    Uri uri = cr.insert(Events.CONTENT_URI, values);

//提交查询并取回游标对象。cur = cr.query(uri，EVENT_PROJECTION，selection，selectionArgs，null)；

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    button = (Button) findViewById(R.id.button1);
    text = (TextView) findViewById(R.id.textView1);
    mAudioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
    button.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            if(ringeronoff == true){
                text.setText("Ringer is On");
                mAudioManager.setRingerMode(AudioManager.RINGER_MODE_NORMAL);
                ringeronoff = false;
            }
            else{
                text.setText("Ringer is Off");
                mAudioManager.setRingerMode(AudioManager.RINGER_MODE_SILENT);
                ringeronoff = true;
            }
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}


}

Answer 1

对于初学者来说，这是错误的，并且不能在Android 4.1上工作：

final Cursor cursor =  contentResolver.query(Uri.parse("content://calendar/calendars"),
        (new String[] { "_id", "displayName", "selected" }), null, null, null);

简单地说，如果您打算使用日历API，则应该使用CalendarContract和子类，并且避免将常量硬编码到代码中，如下所示。

例如，您正在使用的URI - API -包含授权calendar -它应该是com.android.calendar -或者更好的是，直接从content://calendar/calendars传递Uri。