Question

我是编码的新手，当时我在android studio中编码一个聊天应用程序。我当时在编码，当我在其他字词下方插入红线时，我想知道您是否可以帮助我摆脱这些行。

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

    username = findViewById(R.id.username);
    email = findViewById(R.id.email);
    passward = findViewById(R.id.passward);
    btn_register = findViewById(R.id.btn_register);

    auth = FirebaseAuth.getInstance();

    btn_register.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String txt_username = username.getText().toString();
            String txt_email = email.getText().toString();
            String txt_passward = passward.getText().toString();

            if ((TextUtils.isEmpty(txt_username) || (TextUtils.isEmpty(txt_email) || (TextUtils.isEmpty(txt_passward)){
                Toast.makeText(RegisterActivity.this, "All fields are required", Toast.LENGTH_SHORT).show();
            } else if (txt_passward.length() < 6 ){
                Toast.makeText(RegisterActivity.this, "Passward must be atleast 6 chracters", Toast.LENGTH_SHORT).show();
            } else {
                register(txt_username, txt_email, txt_passward);
            }
        }
    });
}

红线显示在else下方，并且显示错误“ else if if”

Answer 1

在第一个条件下，您会错过三个右括号。

只需尝试

if ((TextUtils.isEmpty(txt_username)) || (TextUtils.isEmpty(txt_email)) || (TextUtils.isEmpty(txt_passward)))

Answer 2

尝试删除括号

if ( (TextUtils.isEmpty(txt_username)) || 
     (TextUtils.isEmpty(txt_email))    || 
     (TextUtils.isEmpty(txt_passward)) )
{
//
}

如何解决“否则就没有”？

2 个答案: