use this in Oncreate.
假设编辑文本 id 是 edittext1 。
et1=(EditText)findviewbyid(R.id.editText1)
et1.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
// Add Here whatever you want to do before text changed
}
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
/*我下面的例子是检查电子邮件,它必须包含 .com 和 @ */
ss ="oooo"+input_Email.getText().toString();
a = ss.length();
a--;
int o = 0;
if ((ss.charAt(a) == 'm') && (ss.charAt(a - 1) == 'o')
&& (ss.charAt(a - 2) == 'c')
&& (ss.charAt(a - 3) == '.')) {
o = 1;
while (a >= 0) {
aa = ss.charAt(a);
if (aa == '@' || aa == '.') {
j++;
}
a--;
}
}
if ((j >= 2) && (o == 1)) {
tv8.setTextColor(Color.GREEN);
tv8.setText("Correct");
Email_Check="Correct";
} else {
tv8.setTextColor(Color.RED);
tv8.setText("Invalid Email Address");
Email_Check="Invalid";
}
ss = "";
}
});