Android 程式开发：（二十）内容提供者 —— 20.6 自定义ContentProvider的使用
现在，ContentProvider已经创建好了，可以去尝试使用一下。
1. 使用之前的工程，在布局文件main.xml中添加一些控件。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="ISBN" />
<EditText
android:id="@+id/txtISBN"
android:layout_height="wrap_content"
android:layout_width="fill_parent" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Title" />
<EditText
android:id="@+id/txtTitle"
android:layout_height="wrap_content"
android:layout_width="fill_parent" />
<Button
android:text="Add title"
android:id="@+id/btnAdd"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="onClickAddTitle" />
<Button
android:text="Retrieve titles"
android:id="@+id/btnRetrieve"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="onClickRetrieveTitles" />
</LinearLayout>
2. 在ContentProvidersActivity.java中，添加测试代码。
public class ContentProvidersActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void onClickAddTitle(View view) {
/*
//---add a book---
ContentValues values = new ContentValues();
values.put(BooksProvider.TITLE, ((EditText)
findViewById(R.id.txtTitle)).getText().toString());
values.put(BooksProvider.ISBN, ((EditText)
findViewById(R.id.txtISBN)).getText().toString());
Uri uri = getContentResolver().insert(
BooksProvider.CONTENT_URI, values);
*/
ContentValues values = new ContentValues();
values.put("title", ((EditText)
findViewById(R.id.txtTitle)).getText().toString());
values.put("isbn", ((EditText)
findViewById(R.id.txtISBN)).getText().toString());
Uri uri = getContentResolver().insert(
Uri.parse(
"content://net.manoel.provider.Books/books"),
values);
Toast.makeText(getBaseContext(),uri.toString(),
Toast.LENGTH_LONG).show();
}
public void onClickRetrieveTitles(View view) {
//---retrieve the titles---
Uri allTitles = Uri.parse(
"content://net.manoel.provider.Books/books");
Cursor c;
if (android.os.Build.VERSION.SDK_INT <11) {
//---before Honeycomb---
c = managedQuery(allTitles, null, null, null,
"title desc");
} else {
//---Honeycomb and later---
CursorLoader cursorLoader = new CursorLoader(
this,
allTitles, null, null, null,
"title desc");
c = cursorLoader.loadInBackground();
}
if (c.moveToFirst()) {
do{
Toast.makeText(this,
c.getString(c.getColumnIndex(
BooksProvider._ID)) + ", " +
c.getString(c.getColumnIndex(
BooksProvider.TITLE)) + ", " +
c.getString(c.getColumnIndex(
BooksProvider.ISBN)),
Toast.LENGTH_SHORT).show();
} while (c.moveToNext());
}
}
public void updateTitle() {
ContentValues editedValues = new ContentValues();
editedValues.put(BooksProvider.TITLE, "Android Tips and Tricks");
getContentResolver().update(
Uri.parse(
"content://net.manoel.provider.Books/books/2"),
editedValues,
null,
null);
}
public void deleteTitle() {
//---delete a title---
getContentResolver().delete(
Uri.parse("content://net.manoel.provider.Books/books/2"),
null, null);
//---delete all titles---
getContentResolver().delete(
Uri.parse("content://net.manoel.provider.Books/books"),
null, null);
}
}