通过EditText的setTransformationMethod()隐藏或显示密码

    private Button mBtnPassword;
    private EditText mEtPassword;
    private boolean mbDisplayFlg = false;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mEtPassword = (EditText)findViewById(R.id.password);
        mBtnPassword = (Button)findViewById(R.id.btnPassword);
        mBtnPassword.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Log.d("AndroidTest", "mbDisplayFlg = " + mbDisplayFlg);
                if (!mbDisplayFlg) {
                    // display password text, for example "123456"
                    mEtPassword.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
                } else {
                    // hide password, display "."
                    mEtPassword.setTransformationMethod(PasswordTransformationMethod.getInstance());
                }
                mbDisplayFlg = !mbDisplayFlg;
                mEtPassword.postInvalidate();
            }

        });

    }