Android ContentProvider

1.创建一个布局文件

2. 创建一个应用程序作为Provider

3.新建一个类继承ContentProvider重写它的五个方法

public class MyContentProvide extends ContentProvider {    private SQLiteDatabase db;    private UriMatcher uriMatcher;    @Override    public boolean onCreate() {        DbHelper dbHelper = new DbHelper(getContext());        db = dbHelper.getWritableDatabase();        uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);        //增加uri        uriMatcher.addURI("com.zking.mycontentprovide","person",1);        uriMatcher.addURI("com.zking.mycontentprovide","person/#",2);        return false;    }    @Nullable    @Override    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {        //匹配        int type = uriMatcher.match(uri);        switch (type){            case 1:                return db.query(false,"person",projection,selection,selectionArgs,null,null,sortOrder,null);            case 2:                long id = ContentUris.parseId(uri);                return db.query(false,"person",projection,"_id=?",new String[]{id + ""},null,null,sortOrder,null);        }        return null;    }    @Nullable    @Override    public String getType(Uri uri) {        return null;    }    @Nullable    @Override    public Uri insert(Uri uri, ContentValues values) {        db.insert("person",null,values);        return uri;    }    @Override    public int delete(Uri uri, String selection, String[] selectionArgs) {        return db.delete("person",selection,selectionArgs);    }    @Override    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {        return db.update("person",values,selection,selectionArgs);    }}

然后在清单文件配置

4.创建一个应用程序作为Resolver

public class MainActivity extends AppCompatActivity {    private String contentUrl = "content://com.zking.mycontentprovide";    private ContentResolver cr;    private ListView lv_main_list;    private List<Person> persons = new ArrayList<>();    private MyAdapter myAdapter;    private PopupWindow popupWindow;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        cr = getContentResolver();        initViews();    }    private void initViews() {        lv_main_list = (ListView) findViewById(R.id.lv_main_list);        persons = getPersons(null);        myAdapter = new MyAdapter();        lv_main_list.setAdapter(myAdapter);        lv_main_list.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {            @Override            public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, final long id) {                LinearLayout ll = new LinearLayout(MainActivity.this);                ll.setOrientation(LinearLayout.VERTICAL);                ll.setBackgroundColor(Color.argb(255,255,255,255));                TextView tv_edit = new TextViewUtil(MainActivity.this).setText("编辑").toTextView();                TextView tv_delete = new TextViewUtil(MainActivity.this).setText("删除").toTextView();                ll.addView(tv_edit);                tv_edit.setOnClickListener(new View.OnClickListener() {                    @Override                    public void onClick(View v) {                        final Person person = persons.get(position);                        LinearLayout linearLayout = new LinearLayout(MainActivity.this);                        linearLayout.setOrientation(LinearLayout.VERTICAL);                        final EditText et_id = new EditTextUtil(MainActivity.this,LinearLayout.LayoutParams.class,EditTextUtil.WIDTH_MATH_AND_HEGTI_WRAP).setText(person.getId()+ "").setHint("用户id").toEditText();                        et_id.setEnabled(false);                        final EditText et_name = new EditTextUtil(MainActivity.this,LinearLayout.LayoutParams.class,EditTextUtil.WIDTH_MATH_AND_HEGTI_WRAP).setText(person.getName()+ "").setHint("用户姓名").toEditText();                        final EditText et_age = new EditTextUtil(MainActivity.this,LinearLayout.LayoutParams.class,EditTextUtil.WIDTH_MATH_AND_HEGTI_WRAP).setText(person.getAge()+ "").setHint("用户年龄").toEditText();                        linearLayout.addView(et_id);                        linearLayout.addView(et_name);                        linearLayout.addView(et_age);                        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);                        builder.setMessage("修改");                        builder.setView(linearLayout);                        builder.setNeutralButton("修改", new DialogInterface.OnClickListener() {                            @Override                            public void onClick(DialogInterface dialog, int which) {                                ContentValues contentValues = new ContentValues();                                contentValues.put("name",et_name.getText().toString());                                contentValues.put("age",et_age.getText().toString());                                cr.update(Uri.parse(contentUrl),contentValues,"_id=?",new String[]{et_id.getText().toString()});                                persons = getPersons(null);                                myAdapter.notifyDataSetChanged();                            }                        });                        builder.setPositiveButton("取消",null);                        builder.show();                        popupWindow.dismiss();                    }                });                ll.addView(tv_delete);                tv_delete.setOnClickListener(new View.OnClickListener() {                    @Override                    public void onClick(View v) {                        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);                        builder.setTitle("删除");                        builder.setMessage("你确定删除吗");                        builder.setNegativeButton("是", new DialogInterface.OnClickListener() {                            @Override                            public void onClick(DialogInterface dialog, int which) {                                cr.delete(Uri.parse(contentUrl),"_id=?",new String[]{persons.get(position).getId() + ""});                                persons = getPersons(null);                                myAdapter.notifyDataSetChanged();                            }                        });                        builder.setPositiveButton("否",null);                        builder.show();                        popupWindow.dismiss();                    }                });                popupWindow = new PopupWindow(ll,300,300);                popupWindow.setBackgroundDrawable(new ColorDrawable(Color.argb(0,255,255,255)));                popupWindow.setBackgroundDrawable(new ColorDrawable(0x00000000));                popupWindow.setOutsideTouchable(false);                popupWindow.setFocusable(true);                popupWindow.showAsDropDown(view);                return false;            }        });    }    public List<Person> getPersons(String id){        List<Person> persons = new ArrayList<>();        Uri uri = null;        if (id != null){            uri =  Uri.parse(contentUrl + "/person/" + id);        }else {            uri =  Uri.parse(contentUrl + "/person");        }        Cursor cursor =  cr.query(uri,null,null,null,null);        while (cursor.moveToNext()){            Person p = new Person();            p.setId(cursor.getInt(0));            p.setName(cursor.getString(1));            p.setAge(cursor.getInt(2));            persons.add(p);        }        return persons;    }    private class MyAdapter extends BaseAdapter{        @Override        public int getCount() {            return persons.size();        }        @Override        public Object getItem(int position) {            return persons.get(position);        }        @Override        public long getItemId(int position) {            return position;        }        @Override        public View getView(int position, View convertView, ViewGroup parent) {            LinearLayout linearLayout = new LinearLayout(MainActivity.this);            Person person = persons.get(position);            TextView textView = getTextView();            textView.setText(person.getId() + "");            TextView textView1 = getTextView();            textView1.setText(person.getName() + "");            TextView textView2 = getTextView();            textView2.setText(person.getAge() + "");            linearLayout.addView(textView);            linearLayout.addView(textView1);            linearLayout.addView(textView2);            return linearLayout;        }        private TextView getTextView(){            TextView textView = new TextView(MainActivity.this);            LinearLayout.LayoutParams l = new LinearLayout.LayoutParams(0,LinearLayout.LayoutParams.WRAP_CONTENT);            l.weight = 1;            textView.setLayoutParams(l);            return textView;        }    }    public void query(View view){        LinearLayout linearLayout = new LinearLayout(this);        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT);        final EditText editText = new EditText(this);        editText.setLayoutParams(lp);        editText.setHint("请输入id");        linearLayout.addView(editText);        AlertDialog.Builder builder = new AlertDialog.Builder(this);        builder.setMessage("查询");        builder.setView(linearLayout);        builder.setNeutralButton("查询", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                if (!TextUtils.isEmpty(editText.getText().toString())){                    persons = getPersons(editText.getText().toString());                }else {                    persons = getPersons(null);                }                myAdapter.notifyDataSetChanged();            }        });        builder.setPositiveButton("取消",null);        builder.show();    }    public void insert(View view){        LinearLayout linearLayout = new LinearLayout(this);        linearLayout.setOrientation(LinearLayout.VERTICAL);        final EditText et_name = new EditTextUtil(this,LinearLayout.LayoutParams.class,EditTextUtil.WIDTH_MATH_AND_HEGTI_WRAP).setHint("请输入用户名").toEditText();        final EditText et_age = new EditTextUtil(this,LinearLayout.LayoutParams.class,EditTextUtil.WIDTH_MATH_AND_HEGTI_WRAP).setHint("请输入年龄").toEditText();        et_age.setInputType(InputType.TYPE_CLASS_NUMBER);        linearLayout.addView(et_name);        linearLayout.addView(et_age);        AlertDialog.Builder builder = new AlertDialog.Builder(this);        builder.setMessage("增加");        builder.setView(linearLayout);        builder.setNeutralButton("添加", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                ContentValues contentValues = new ContentValues();                contentValues.put("name",et_name.getText().toString());                contentValues.put("age",et_age.getText().toString());                cr.insert(Uri.parse(contentUrl),contentValues);                persons = getPersons(null);                myAdapter.notifyDataSetChanged();            }        });        builder.setPositiveButton("取消",null);        builder.show();    }}