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;
 }

你也可以检查所有的EditText字符串在一个If条件:像这样

if (mString.matches("") || fString.matches("") || gender==null || docString.matches("") || dString.matches("")) {
                Toast.makeText(WriteActivity.this,"Data Incomplete", Toast.LENGTH_SHORT).show();
            }

我曾经做过类似的事情;

EditText usernameEditText = (EditText) findViewById(R.id.editUsername);
sUsername = usernameEditText.getText().toString();
if (sUsername.matches("")) {
    Toast.makeText(this, "You did not enter a username", Toast.LENGTH_SHORT).show();
    return;
}

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;
 }