当编辑文本失去焦点时,执行回调,如下:
et_username.setOnFocusChangeListener(new OnFocusChangeListener()
{
@Override
public void onFocusChange(View v, boolean hasFocus) {
// TODO Auto-generated method stub
if(!hasFocus){
if(et_username.getText().toString().trim().length()<4){
Toast.makeText(RegisterActivity.this, "用户名不能小于4个字符", Toast.LENGTH_SHORT).show();
}
}
}
});