一、打勾显示输入的密码

private EditText et;
	private CheckBox cb;
	
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.password);
		
		et = (EditText)findViewById(R.id.editText1);
		cb = (CheckBox)findViewById(R.id.checkBox1);
		
		cb.setOnCheckedChangeListener(new OnCheckedChangeListener(){

			public void onCheckedChanged(CompoundButton buttonView,
					boolean isChecked) {
				if(cb.isChecked()){
					et.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
				}
				else{
					et.setTransformationMethod(PasswordTransformationMethod.getInstance());
				}
			}
			
		});
	}

实时监视EditText内输入的字符

mEditText1.addTextChangedListener(new TextWatcher(){

			public void afterTextChanged(Editable s) {
				
			}

			public void beforeTextChanged(CharSequence s, int start, int count,
					int after) {
				
			}

			public void onTextChanged(CharSequence s, int start, int before,
					int count) {
				
			}
			
		});