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我正在使用 android 4.1 API 创建一个 android 应用程序，但我遇到了问题。

我的代码编译似乎有问题，虽然它没有给我任何错误，但当我尝试在 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);

//提交查询并返回一个 Cursor 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;
}


}
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1 回答 1

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对于初学者来说，这是错误的，并且不适用于 Android 4.1：

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

简而言之，如果您打算使用日历 API，您应该使用CalendarContract和 子类，并避免像这样将常量硬编码到您的代码中。

例如，您正在使用的 URI - content://calendar/calendars- 包含权限calendar- 它应该是com.android.calendar- 甚至更好，只需从 API传递Uri 。

于 2012-08-04T15:49:51.233 回答