ContentProvider使用

package activity.cyq.contentprovidertenderer;

import android.content.ContentProvider;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;

public class MyContentProvider extends ContentProvider {
    public static final Uri URI=Uri.parse("content://cyq.activity.MyContentProvider");
    private SQLiteDatabase database;

    @Override
    public boolean onCreate() {
        database = getContext().openOrCreateDatabase("ContentProvider", Context.MODE_PRIVATE, null);
        database.execSQL("Create Table contacts( _id INTEGER PRIMARY KEY AUTOINCREMENT, username TEXT DEFAULT NONE , cellPhotoNumber TEXT DEFAULT NONE) ");
        return false;
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        Cursor cursor = database.query("contacts", null, null, null, null, null, null);
        return cursor;
    }

    @Override
    public String getType(Uri uri) {
        return null;
    }

    @Override
    public Uri insert(Uri uri, ContentValues values) {
        database.insert("contacts", "_id", values);
        return null;
    }

    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        return 0;
    }

    @Override
    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
        return 0;
    }
}

package activity.cyq.contentprovidertenderer;

import android.content.ContentValues;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    private EditText usernameEdit;
    private EditText cellPhotoNumberEdit;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        usernameEdit = (EditText) findViewById(R.id.username);
        cellPhotoNumberEdit = (EditText) findViewById(R.id.cellPhotoNumber);

        findViewById(R.id.add).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ContentValues values = new ContentValues();
                values.put("username", usernameEdit.getText().toString());
                values.put("cellPhotoNumber", cellPhotoNumberEdit.getText().toString());
                getContentResolver().insert(MyContentProvider.URI, values);
                Toast.makeText(MainActivity.this, "数据库创建成功", Toast.LENGTH_SHORT).show();

            }
        });

    }

}