java - 我无法从 EditText 获取值并使用该值

Question

我几个小时都无法解决以下问题。我尝试从 EditText 获取用户输入的值，以便我可以使用它们。

public class Registrace extends AppCompatActivity implements View.OnClickListener {
private static final Pattern PASSWORD_PATTERN =
        Pattern.compile("^" + "(?=.*[0-9])" +
                "(?=.*[a-z])" + "(?=.*[A-Z])" + "(?=.*[@#$%^&+=])" + "(?=\\s+$)" + ".{6,}" + "$");


public EditText editPrijmeni, editJmeno, editEmail, editPwd, editPwd2;

public String Mess = null;

public String jmeno, prijmeni, email, heslo, heslo2;
 Button btn;


@Override
protected void onCreate(Bundle savedInstanceState) {


    super.onCreate(savedInstanceState);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
    setContentView(R.layout.activity_registrace);

    TextView login = (TextView) findViewById(R.id.lnkLogin);
    login.setMovementMethod(LinkMovementMethod.getInstance());
    login.setOnClickListener(this);

    editJmeno = (EditText) findViewById(R.id.txtJmeno);
    jmeno = editJmeno.getText().toString().trim();

    editPrijmeni = (EditText) findViewById(R.id.txtPrijmeni);
    prijmeni = editPrijmeni.getEditableText().toString().trim();

    editEmail = (EditText) findViewById(R.id.txtEmail);
    email = editEmail.getEditableText().toString().trim();

    editPwd = (EditText) findViewById(R.id.txtPassword);
    heslo = editPwd.getEditableText().toString().trim();

    editPwd2 = (EditText) findViewById(R.id.txtPassword2);
    heslo2 = editPwd2.getEditableText().toString().trim();

    btn = (Button) findViewById(R.id.btnRegistrace);
    btn.setOnClickListener(this);

}

public boolean validujPrijmeni() {
     if(prijmeni.isEmpty()) {
         Mess = "Příjmení" + "\n";
         return false;


     } else {
         return true;
     }

}


@Override
public void onClick(View v) {


    switch (v.getId()) {
        case R.id.lnkLogin:
            Intent intent = new Intent(Registrace.this, Login.class);
            startActivity(intent);
            break;
        case R.id.btnRegistrace:
            Toast.makeText(this, "Registrace", Toast.LENGTH_SHORT).show();

            if(!prijmeni.isEmpty()) {
                Toast.makeText(this, prijmeni, Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(this, "Zadej příjmení", Toast.LENGTH_SHORT).show();
            }
            break;
    }

}
}

为了确保 EditText 值正确存储，我尝试使用 Toast 文本显示它们。但是在填写值并按下按钮后，我仍然从 if 语句中获得“else” block ，以获取“switch”中的空 EditText。我不确定构造函数声明应该位于 onCreate 主体中还是外部。有人可以帮我吗？？？非常感谢。

这是layout.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center">

<TextView
    android:id="@+id/loginscrn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginTop="30dp"
    android:text="Registrace"
    android:textSize="20dp"
    android:textStyle="bold" />

<TextView
    android:id="@+id/fstTxt"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="100dp"
    android:layout_marginTop="15dp"
    android:text="Příjmení" />
<EditText
    android:id="@+id/txtPrijmeni"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="100dp"
    android:ems="10" />
<TextView
    android:id="@+id/secTxt"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="100dp"
    android:layout_marginTop="15dp"
    android:text="Jméno"/>
<EditText
    android:id="@+id/txtJmeno"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="100dp"
    android:ems="10"/>
<TextView
    android:id="@+id/thirdTxt"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Email"
    android:layout_marginLeft="100dp" />
<EditText
    android:id="@+id/txtEmail"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="100dp"
    android:ems="10" />
<TextView
    android:id="@+id/fourTxt"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Heslo"
    android:layout_marginLeft="100dp" />
<EditText
    android:id="@+id/txtPassword"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="100dp"
    android:inputType="textPassword"
    android:ems="10" />

<TextView
    android:id="@+id/fiveTxt"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Heslo, znova pro kontrolu"
    android:layout_marginLeft="100dp" />
<EditText
    android:id="@+id/txtPassword2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="100dp"
    android:inputType="textPassword"
    android:ems="10" />
<Button
    android:id="@+id/btnRegistrace"
    android:onClick="Registrace"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="100dp"
    android:text="Registrovat" />
<TextView android:id="@+id/lnkLogin"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="40dp"
    android:text="Jste již registrován?? Přihlaste se zde."
    android:gravity="center"
    android:textSize="20dp"
    android:textColor="#3F51B5"
    android:onClick="test"/>

Answer 1

执行此操作:在 onClick() 方法中执行以下操作:prijmeni = editPrijmeni.getEditableText().toString().trim();。

您在创建 Activity 时执行此操作，因此 EditText 控件为空。它不会在更改时自动更新 prijmeni 字符串。

下面是经过一些小改进后的代码的样子。
它还可以进一步完善，但看起来你才刚刚开始，所以已经很好了。

public class Registrace extends AppCompatActivity implements View.OnClickListener {
    private static final Pattern PASSWORD_PATTERN =
        Pattern.compile("^" + "(?=.*[0-9])" +
                "(?=.*[a-z])" + "(?=.*[A-Z])" + "(?=.*[@#$%^&+=])" + "(?=\\s+$)" + ".{6,}" + "$");

    private EditText editPrijmeni;
    private EditText editJmeno; 
    private EditText editEmail;
    private EditText editPwd;
    private EditText editPwd2;
    private Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        setContentView(R.layout.activity_registrace);

        // Shouldn't you use a button instead of a text view?
        // It seems you want a "Login" button to go to a LoginActivity
        final TextView login = (TextView) findViewById(R.id.lnkLogin);
        login.setMovementMethod(LinkMovementMethod.getInstance());
        login.setOnClickListener(this);

        // You could use https://jakewharton.github.io/butterknife which simplifies this boilerplate code a lot 
        editJmeno = (EditText) findViewById(R.id.txtJmeno);
        editPrijmeni = (EditText) findViewById(R.id.txtPrijmeni);
        editEmail = (EditText) findViewById(R.id.txtEmail);
        editPwd = (EditText) findViewById(R.id.txtPassword);
        editPwd2 = (EditText) findViewById(R.id.txtPassword2);
        btn = (Button) findViewById(R.id.btnRegistrace);
        btn.setOnClickListener(this);
    }

    public boolean validujPrijmeni() {
        // if 'Mess' was for a validation message don't set it in the validation method.
        // define a string in your resources.
        // show/hide a TextView with that message from where you use the validation method.
        final String prijmeni = editPrijmeni.getEditableText().toString().trim();
        return !prijmeni.isEmpty();
    }

    // I would not declare the activity as a OnClickListener but use anonymous classes in the onCreate method
    // calling method on this class.
    // or if you use ButterKnife you can do so with OnClick annotations.
    // This is to prevent the use of switch which is not great code.
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.lnkLogin:
                Intent intent = new Intent(Registrace.this, Login.class);
                startActivity(intent);
                break;
        case R.id.btnRegistrace:
            Toast.makeText(this, "Registrace", Toast.LENGTH_SHORT).show();

            final String prijmeni = editPrijmeni.getEditableText().toString().trim();
            if (this.validujPrijmeni()) {
                Toast.makeText(this, prijmeni, Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(this, "Zadej příjmení", Toast.LENGTH_SHORT).show();
            }
            break;
        }
    }

}