Question

当我按下注册而不在字段中键入任何内容时，它不会显示来自try catch块的警告框。此外，当电子邮件已经在数据库中时，它应该显示警告框但它不起作用。

public class activityregister extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_register);

    final EditText register_age = (EditText) findViewById(R.id.register_age);
    final EditText register_email = (EditText) findViewById(R.id.emails_reg);
    final EditText register_name = (EditText) findViewById(R.id.register_name);
    final EditText register_password = (EditText) findViewById(R.id.register_password);
    final Button reg_poga = (Button) findViewById(R.id.registacijas_poga);
    reg_poga.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            final String name = register_name.getText().toString();
            final String email = register_email.getText().toString();
            final String age =  register_age.getText().toString();
            final String password = register_password.getText().toString();
           boolean pareizi = false;
          final Response.Listener <String> responseListener = new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    try{
                        JSONObject jsonResponse = new JSONObject(response);
                        boolean success = jsonResponse.getBoolean("success"
                        );
                        if (success) {
                            Intent intent = new Intent(activityregister.this, LoginRegister.class);
                            activityregister.this.startActivity(intent);
                        }
                    } catch (JSONException e){
                       AlertDialog.Builder builder = new AlertDialog.Builder(activityregister.this);
                        builder.setMessage("Register is not completed!")
                                .setNegativeButton("Retry the registration!",null)
                        .create()
                        .show();
                        e.printStackTrace();
                    }
                }
            };

               RegisterRequest registerRequestt= new RegisterRequest(name, email, age, password, responseListener);
               RequestQueue Que = Volley.newRequestQueue(activityregister.this);
               Que.add(registerRequestt);
        }
    });
}
}

Answer 1

您需要在catch块中使用 Exception 代替 JSONException 。

如果你在catch块中传递 Exception ，那么它将捕获所有类型的异常，因为Exception是所有异常类型的Parent类

现在您正在使用 JSONException ，因此它只会捕获与JSON相关的错误。

在你的代码中使用这样的

                   try{
                        JSONObject jsonResponse = new JSONObject(response);
                        boolean success = jsonResponse.getBoolean("success"
                        );
                        if (success) {
                            Intent intent = new Intent(activityregister.this, LoginRegister.class);
                            activityregister.this.startActivity(intent);
                        }
                    } catch (Exception e){
                       AlertDialog.Builder builder = new AlertDialog.Builder(activityregister.this);
                        builder.setMessage("Register is not completed!")
                                .setNegativeButton("Retry the registration!",null)
                        .create()
                        .show();
                        e.printStackTrace();
                    }

根据你的第二个要求，如果电子邮件是空的等等，我在这里给你的完整代码进行更正

public class activityregister extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_register);

    final EditText register_age = (EditText) findViewById(R.id.register_age);
    final EditText register_email = (EditText) findViewById(R.id.emails_reg);
    final EditText register_name = (EditText) findViewById(R.id.register_name);
    final EditText register_password = (EditText) findViewById(R.id.register_password);
    final Button reg_poga = (Button) findViewById(R.id.registacijas_poga);
    reg_poga.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            final String name = register_name.getText().toString();
            final String email = register_email.getText().toString();
            final String age =  register_age.getText().toString();
            final String password = register_password.getText().toString();
           boolean pareizi = false;

           if(TextUtils.isEmpty(email)){
               // Here show alert or show toast , if email is empty
           } else {
          final Response.Listener <String> responseListener = new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    try{
                        JSONObject jsonResponse = new JSONObject(response);
                        boolean success = jsonResponse.getBoolean("success"
                        );
                        if (success) {
                            Intent intent = new Intent(activityregister.this, LoginRegister.class);
                            activityregister.this.startActivity(intent);
                        }
                    } catch (JSONException e){
                       AlertDialog.Builder builder = new AlertDialog.Builder(activityregister.this);
                        builder.setMessage("Register is not completed!")
                                .setNegativeButton("Retry the registration!",null)
                        .create()
                        .show();
                        e.printStackTrace();
                    }
                }
            };

               RegisterRequest registerRequestt= new RegisterRequest(name, email, age, password, responseListener);
               RequestQueue Que = Volley.newRequestQueue(activityregister.this);
               Que.add(registerRequestt);
        }

        }});
    }
}

尝试catch无法捕获错误

1 个答案: