密码框显示和隐藏

import android.app.Activity;
import android.graphics.Rect;
import android.os.Bundle;
import android.text.method.HideReturnsTransformationMethod;
import android.text.method.PasswordTransformationMethod;
import android.text.method.TransformationMethod;
import android.view.View;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;

public class PasswordIsShowTestActivity extends Activity {

private EditText username;
private EditText password;
private CheckBox cbBox ;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

username = (EditText)findViewById(R.id.editText1);
password = (EditText)findViewById(R.id.editText2);
cbBox = (CheckBox)findViewById(R.id.checkBox1);
cbBox.setOnCheckedChangeListener(new OnCheckedChangeListener() {

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(cbBox.isChecked()){
password.setTransformationMethod(
HideReturnsTransformationMethod.getInstance());
}else{
password.setTransformationMethod(
PasswordTransformationMethod.getInstance());
}
}
});
}
}