我正在尝试更新＆＃39;名称＆＃39;在该位置找到的首选APN数据库表的列：content：// telephony / carriers / preferapn。但是，我的应用程序的ContentResolver.update（）始终返回0，表示没有更新任何行。我已经拥有应用程序的root访问权限，并在运行update（）之前以编程方式确认它。
可以找到有关表格列的详细信息here和here。我还确保参考documentation如何调用更新函数。
更新方法：
public boolean setAPN(String newAPN, TextView t){
//get URI objects for the tables
final Uri APN_TABLE_URI = Uri.parse("content://telephony/carriers");
final Uri PREFERRED_APN_URI = Uri.parse("content://telephony/carriers/preferapn");
//Confirm permissions
PackageManager pm = getPackageManager();
if (pm.checkPermission(permission.WRITE_APN_SETTINGS, getPackageName()) == PackageManager.PERMISSION_GRANTED) {
//Update name field
ContentResolver resolver = this.getContentResolver();
ContentValues values = new ContentValues();
values.put("name", newAPN);
long rc = resolver.update(PREFERRED_APN_URI, values, null, null);
//Display the row contents (always has the original fields, doesn't update)
Cursor c = getContentResolver().query(PREFERRED_APN_URI, null, null, null, null);
c.moveToFirst();
int index = c.getColumnIndex("_id"); //getting index of required column
Short id = c.getShort(index); //getting APN's id from
index = c.getColumnIndex("name");
String name = c.getString(index);
index = c.getColumnIndex("mcc");
String mcc = c.getString(index);
index = c.getColumnIndex("mnc");
String mnc = c.getString(index);
index = c.getColumnIndex("numeric");
String numeric = c.getString(index);
t.setText(" ID:" + id + "\n" +
" APN Name: " + name + "\n" +
" MCC: " + mcc + "\n" +
" MNC: " + mnc + "\n" +
" Numeric: " + numeric + "\n"
);
} else {
t.setText(" You don't have permission to do this. ");
}
return true;
}
如前所述，我也有权限：＆＃34; android.permission.WRITE_APN_SETTINGS＆＃34;在清单文件中：
为了我的特殊目的，我是否错误地调用了更新功能？或者使用update（）以错误的方式解决这个问题？
答案 0 :(得分：3)
这个问题已经死了差不多一个月了，但是我为这个问题做了一个解决方法，想分享它。解决方法包括复制除名称字段之外的现有首选APN条目，将新APN插入运营商列表，然后使用新生成的ID将新APN设置为首选。
public int InsertAPN(String name){
//Set the URIs and variables
int id = -1;
boolean existing = false;
final Uri APN_TABLE_URI = Uri.parse("content://telephony/carriers");
final Uri PREFERRED_APN_URI = Uri.parse("content://telephony/carriers/preferapn");
//Check if the specified APN is already in the APN table, if so skip the insertion
Cursor parser = getContentResolver().query(APN_TABLE_URI, null, null, null, null);
parser.moveToLast();
while (parser.isBeforeFirst() == false){
int index = parser.getColumnIndex("name");
String n = parser.getString(index);
if (n.equals(name)){
existing = true;
Toast.makeText(getApplicationContext(), "APN already configured.",Toast.LENGTH_SHORT).show();
break;
}
parser.moveToPrevious();
}
//if the entry doesn't already exist, insert it into the APN table
if (!existing){
//Initialize the Content Resolver and Content Provider
ContentResolver resolver = this.getContentResolver();
ContentValues values = new ContentValues();
//Capture all the existing field values excluding name
Cursor apu = getContentResolver().query(PREFERRED_APN_URI, null, null, null, null);
apu.moveToFirst();
int index;
index = apu.getColumnIndex("apn");
String apn = apu.getString(index);
index = apu.getColumnIndex("type");
String type = apu.getString(index);
index = apu.getColumnIndex("proxy");
String proxy = apu.getString(index);
index = apu.getColumnIndex("port");
String port = apu.getString(index);
index = apu.getColumnIndex("user");
String user = apu.getString(index);
index = apu.getColumnIndex("password");
String password = apu.getString(index);
index = apu.getColumnIndex("server");
String server = apu.getString(index);
index = apu.getColumnIndex("mmsc");
String mmsc = apu.getString(index);
index = apu.getColumnIndex("mmsproxy");
String mmsproxy = apu.getString(index);
index = apu.getColumnIndex("mmsport");
String mmsport = apu.getString(index);
index = apu.getColumnIndex("mcc");
String mcc = apu.getString(index);
index = apu.getColumnIndex("mnc");
String mnc = apu.getString(index);
index = apu.getColumnIndex("numeric");
String numeric = apu.getString(index);
//Assign them to the ContentValue object
values.put("name", name); //the method parameter
values.put("apn", apn);
values.put("type", type);
values.put("proxy", proxy);
values.put("port", port);
values.put("user", user);
values.put("password", password);
values.put("server", server);
values.put("mmsc", mmsc);
values.put("mmsproxy", mmsproxy);
values.put("mmsport", mmsport);
values.put("mcc", mcc);
values.put("mnc", mnc);
values.put("numeric", numeric);
//Actual insertion into table
Cursor c = null;
try{
Uri newRow = resolver.insert(APN_TABLE_URI, values);
if(newRow != null){
c = resolver.query(newRow, null, null, null, null);
int idindex = c.getColumnIndex("_id");
c.moveToFirst();
id = c.getShort(idindex);
}
}
catch(SQLException e){}
if(c !=null ) c.close();
}
return id;
}
//Takes the ID of the new record generated in InsertAPN and sets that particular record the default preferred APN configuration
public boolean SetPreferredAPN(int id){
//If the id is -1, that means the record was found in the APN table before insertion, thus, no action required
if (id == -1){
return false;
}
Uri.parse("content://telephony/carriers");
final Uri PREFERRED_APN_URI = Uri.parse("content://telephony/carriers/preferapn");
boolean res = false;
ContentResolver resolver = this.getContentResolver();
ContentValues values = new ContentValues();
values.put("apn_id", id);
try{
resolver.update(PREFERRED_APN_URI, values, null, null);
Cursor c = resolver.query(PREFERRED_APN_URI, new String[]{"name", "apn"}, "_id="+id, null, null);
if(c != null){
res = true;
c.close();
}
}
catch (SQLException e){}
return res;
}
然后您可以像这样调用方法：
int identity = InsertAPN(NEW_APN_NAME);
SetPreferredAPN(identity);