当我的验证条件在另一个类中时，如何重定向到另一个活动

Question

我有一个登录表单，它验证用户名或密码是否与数据库中的匹配，但我在另一个java类中编码了验证，它看起来像这样：

AlertDialog dialog;
Context context;
public background (Context context){
this.context = context;
}
@Override
protected void onPreExecute() {
dialog = new AlertDialog.Builder(context).create();
dialog.setTitle("Login Status");
}
@Override
protected void onPostExecute(String s) {
dialog.setMessage(s);
dialog.show();
}

@Override
protected String doInBackground(String... voids) {
String result =  "";
String user = voids[0];
String pass = voids[1];
String connStr = "http://xzylrey1.heliohost.org/loginandroid.php";
try {
URL url = new URL(connStr);
HttpURLConnection http = (HttpURLConnection) url.openConnection();
http.setRequestMethod("POST");
http.setDoInput(true);
http.setDoOutput(true);
OutputStream ops = http.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(ops, "UTF-8"));
String data = URLEncoder.encode("user", "UTF-8") + "=" + URLEncoder.encode(user, "UTF-8")
+ "&&" + URLEncoder.encode("pass", "UTF-8") + "=" + URLEncoder.encode(pass, "UTF-8");
writer.write(data);
writer.flush();
writer.close();
ops.close();
InputStream ips = http .getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(ips, "ISO-8859-1"));
String line = "";
while((line = reader.readLine()) != null){
result += line;
}
reader.close();
ips.close();
http.disconnect();
return result;
} catch (MalformedURLException e) {
result = e.getMessage();
} catch (IOException e) {
result = e.getMessage();
}

return result;

这是主要类别：

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_username =  findViewById(R.id.et_username);
etPassword =  findViewById(R.id.et_Password);
btnLogin = findViewById(R.id.btn_Login);

}
public void moveToActivityTwo(){
Intent intent = new Intent(MainActivity.this, Main2Activity.class);
startActivity(intent);
}
public void loginBtn(View view) {
String user = et_username.getText().toString();
String pass = etPassword.getText().toString();

background bg = new background(this);
bg.execute(user, pass);
moveToActivityTwo();

我试着把这个方法放在bg.execute行下面，但它会自动重定向到另一个活动，还有其他方法吗？

Answer 1

您需要将moveToActivityTwo()方法移动到onPostExecute()方法的末尾。

它看起来是这样的：

protected void onPostExecute(String s) {
dialog.setMessage(s);
dialog.show();
context.moveToActivityTwo();
}

它调用回调模式。