我正在尝试使用内容提供者，但是出现了一个错误：“Failed to find provider info for com.example.alex.hopefulyworks”。
这里是清单文件和内容提供者：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.alex.hopefulythisworks" >
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<provider android:name=".ColorContentProvider"
android:authorities="com.example.alex.hopefulythisworks.ColorContentProvider"
android:enabled="true"
android:exported="true" >
</provider>
</application>
</manifest>
package com.example.alex.hopefulythisworks;
....
public class ColorContentProvider extends ContentProvider {
private ColorHelper database;
private static final String AUTHORITY
= "com.example.alex.hopefulythisworks";
private static final String BASE_PATH
= "tasks";
public static final Uri CONTENT_URI
= Uri.parse("content://" + AUTHORITY + "/" + BASE_PATH);
public static final String CONTENT_URI_PREFIX
= "content://" + AUTHORITY + "/" + BASE_PATH + "/";
private static final UriMatcher sURIMatcher =
new UriMatcher(UriMatcher.NO_MATCH);
private static final int COLOR = 1;
private static final int COLOR_ROW = 2;
static {
sURIMatcher.addURI(AUTHORITY, BASE_PATH, COLOR);
sURIMatcher.addURI(AUTHORITY, BASE_PATH + "/#", COLOR_ROW);
}
@Override
public boolean onCreate() {
database = new ColorHelper(getContext());
Log.d("contentprovider" , "inside content provider oncreate ");
return false;
}
@Override
public Uri insert(Uri uri, ContentValues values) {
int uriType = sURIMatcher.match(uri);
SQLiteDatabase sqlDB = database.getWritableDatabase();
long id = 0;
switch (uriType) {
case COLOR:
id = sqlDB.insert(ColorTable.TABLE_TASK,
null, values);
break;
default:
throw new IllegalArgumentException("Unknown URI: "
+ uri);
}
getContext().getContentResolver().notifyChange(uri, null);
return Uri.parse( CONTENT_URI_PREFIX + id);
}
@Override
public String getType(Uri uri) {
return null;
}
@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
// check if the caller has requested a column which does not exists
ColorTable.validateProjection( projection );
// Using SQLiteQueryBuilder instead of query() method
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
queryBuilder.setTables( ColorTable.TABLE_TASK );
switch ( sURIMatcher.match(uri) ) {
case COLOR:
break;
case COLOR_ROW:
// add the task ID to the original query
queryBuilder.appendWhere( ColorTable.COLUMN_ID + "=" + uri.getLastPathSegment() );
break;
default:
throw new IllegalArgumentException("Invalid URI: " + uri);
}
System.out.println("before null check");
if(database == null){
System.out.println("database is null");
database = new ColorHelper(getContext());
}
System.out.println("after null check");
SQLiteDatabase db = database.getWritableDatabase();
Cursor cursor = queryBuilder.query( db, projection, selection,
selectionArgs, null, null, sortOrder);
// notify listeners
cursor.setNotificationUri(getContext().getContentResolver(), uri);
return cursor;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
SQLiteDatabase sqlDB = database.getWritableDatabase();
int rowsDeleted = 0;
switch ( sURIMatcher.match(uri) ) {
case COLOR:
rowsDeleted = sqlDB.delete(ColorTable.TABLE_TASK, selection, selectionArgs);
break;
case COLOR_ROW:
String id = uri.getLastPathSegment();
if (TextUtils.isEmpty(selection)) {
rowsDeleted = sqlDB.delete( ColorTable.TABLE_TASK,
ColorTable.COLUMN_ID + "=" + id,
null);
} else {
rowsDeleted = sqlDB.delete( ColorTable.TABLE_TASK,
ColorTable.COLUMN_ID + "=" + id
+ " and " + selection,
selectionArgs);
}
break;
default:
throw new IllegalArgumentException("Invalid URI: " + uri);
}
getContext().getContentResolver().notifyChange(uri, null);
return rowsDeleted;
}
@Override
public int update(Uri uri, ContentValues values, String selection , String[] selectionArgs) {
SQLiteDatabase sqlDB = database.getWritableDatabase();
int rowsUpdated = 0;
switch ( sURIMatcher.match(uri) ) {
case COLOR:
rowsUpdated = sqlDB.update( ColorTable.TABLE_TASK,
values,
selection,
selectionArgs);
break;
case COLOR_ROW:
String id = uri.getLastPathSegment();
if (TextUtils.isEmpty(selection)) {
rowsUpdated = sqlDB.update( ColorTable.TABLE_TASK,
values,
ColorTable .COLUMN_ID + "=" + id,
null );
} else {
rowsUpdated = sqlDB.update( ColorTable.TABLE_TASK,
values,
ColorTable.COLUMN_ID + "=" + id
+ " and " + selection,
selectionArgs);
}
break;
default:
throw new IllegalArgumentException("Invalid URI: " + uri);
}
getContext().getContentResolver().notifyChange(uri, null);
return rowsUpdated;
}
}