试试这个:

EditText txtUserName = (EditText) findViewById(R.id.txtUsername);
String strUserName = usernameEditText.getText().toString();
if (strUserName.trim().equals("")) {
    Toast.makeText(this, "plz enter your name ", Toast.LENGTH_SHORT).show();
    return;
}

或者像这样使用TextUtils类:

if(TextUtils.isEmpty(strUserName)) {
    Toast.makeText(this, "plz enter your name ", Toast.LENGTH_SHORT).show();
    return;
}

尝试使用If ELSE If条件。您可以轻松地验证editText字段。

 if(TextUtils.isEmpty(username)) {
                userNameView.setError("User Name Is Essential");
                return;
         } else  if(TextUtils.isEmpty(phone)) {
                phoneView.setError("Please Enter Your Phone Number");
                return;
            }

对于验证EditText使用edittext# setError方法来显示错误，对于检查空值或空值使用内置的android类TextUtils.isEmpty(strVar)，如果strVar为空或零长度返回true

EditText etUserName = (EditText) findViewById(R.id.txtUsername);
String strUserName = etUserName.getText().toString();

 if(TextUtils.isEmpty(strUserName)) {
    etUserName.setError("Your message");
    return;
 }

if(TextUtils.isEmpty(textA.getText())){
            showToast(it's Null");
        }

你可以使用TextUtils。isEmpty就像我的例子! 祝你好运

这个函数对我有用

private void checkForm() {
    EditText[] allFields = {
        field1_txt,
        field2_txt,
        field3_txt,
        field4_txt
    };
    
    List < EditText > ErrorFields = new ArrayList < EditText > (); 

    for (EditText edit: allFields) {
        if (TextUtils.isEmpty(edit.getText())) {

            // EditText was empty
            ErrorFields.add(edit); //add empty Edittext only in this ArayList
            
            for (int i = 0; i < ErrorFields.size(); i++) {
                EditText currentField = ErrorFields.get(i);
                currentField.setError("this field required");
                currentField.requestFocus();
            }
        }
    }
}

试试这个:

EditText txtUserName = (EditText) findViewById(R.id.txtUsername);
String strUserName = usernameEditText.getText().toString();
if (strUserName.trim().equals("")) {
    Toast.makeText(this, "plz enter your name ", Toast.LENGTH_SHORT).show();
    return;
}

或者像这样使用TextUtils类:

if(TextUtils.isEmpty(strUserName)) {
    Toast.makeText(this, "plz enter your name ", Toast.LENGTH_SHORT).show();
    return;
}