从Android应用程序打开Whatsapp联系人列表

Question

我是Android新手，并尝试执行以下任务：-我想打开Whatsapp联系人列表并获取选定的联系人数据。我能够完成一半的工作。Whatsapp联系人列表打开，但是一旦我按任何联系人，我的应用程序就会崩溃。这是我的代码：

要打开Whatsapp联系人列表：

btnChoose.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(Intent.ACTION_PICK);
            intent.setPackage("com.whatsapp");
            try{
                Toast.makeText(AddScheduleActivity.this, "going out activity", Toast.LENGTH_SHORT).show();
                startActivityForResult(intent, 1);
                Toast.makeText(AddScheduleActivity.this, "getting In activity", Toast.LENGTH_SHORT).show();
            } catch (Exception e) {
                Toast.makeText(AddScheduleActivity.this, "Whatsapp not found", Toast.LENGTH_SHORT).show();  //no activity found to handle this intent means whatsapp is not installed
            }
        }
    });

获得选择：-

@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
    super.onActivityResult(requestCode, resultCode, intent);
    Toast.makeText(AddScheduleActivity.this, "Ok In", Toast.LENGTH_SHORT).show();

    switch (requestCode) {
        case 1:
            if(resultCode == RESULT_OK){
                if(intent.hasExtra("contact")){

                    Toast.makeText(AddScheduleActivity.this, "Ok working", Toast.LENGTH_SHORT).show();
                    Uri uri = intent.getData();
                    //Query the content uri
                    Cursor cursor = getContentResolver().query(uri, null, null, null, null);
                    cursor.moveToFirst();
                    // column index of the phone number
                    int  phoneIndex =cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER);
                    // column index of the contact name
                    int  nameIndex =cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME);
                    contactNumber = cursor.getString(phoneIndex);
                    name = cursor.getString(nameIndex);

                }
            }
            break;

        default:
            break;
    }
}

如果我没有选择任何联系人并按回，则在这种情况下不会崩溃

提前致谢。

Answer 1

最后自己解决了这个问题。这是编辑后的代码：

@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
    super.onActivityResult(requestCode, resultCode, intent);

    switch (requestCode) {
        case 1:
            if(resultCode == RESULT_OK){

                if(intent.hasExtra("contact")){
                    String number = intent.getStringExtra("contact");

                    Toast.makeText(AddScheduleActivity.this, number, Toast.LENGTH_LONG).show();

                }
            }
            break;

        default:
            break;
    }
}