Android之EditText 为密码输入框时，密码的显示与隐藏

实现输入框密码文本的显示与隐藏有两种，一种是通过直接改变android:inputType，一种是通过改变android.text.method.TransformationMethod。

方式一：改变android:inputType的值

实现代码如下：

	
	/**
	 * 密码显示或隐藏 （切换）
	 */
	private void showOrHide(EditText etPassword){
		//记住光标开始的位置
		int pos = etPassword.getSelectionStart();
		if(etPassword.getInputType()!= (InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD)){//隐藏密码
			etPassword.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
		}else{//显示密码
			etPassword.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD);
		}
		etPassword.setSelection(pos);
		
	}
	

参见：android:inputType

对应的值与描述如下：

Constant	Value	Description
none	0x00000000	There is no content type. The text is not editable.
text	0x00000001	Just plain old text. Corresponds to TYPE_CLASS_TEXT | TYPE_TEXT_VARIATION_NORMAL.
textCapCharacters	0x00001001	Can be combined with text and its variations to request capitalization of all characters. Corresponds to TYPE_TEXT_FLAG_CAP_CHARACTERS.
textCapWords	0x00002001	Can be combined with text and its variations to request capitalization of the first character of every word. Corresponds to TYPE_TEXT_FLAG_CAP_WORDS.
textCapSentences	0x00004001	Can be combined with text and its variations to request capitalization of the first character of every sentence. Corresponds to TYPE_TEXT_FLAG_CAP_SENTENCES.
textAutoCorrect	0x00008001	Can be combined with text and its variations to request auto-correction of text being input. Corresponds to TYPE_TEXT_FLAG_AUTO_CORRECT.
textAutoComplete	0x00010001	Can be combined with text and its variations to specify that this field will be doing its own auto-completion and talking with the input method appropriately. Corresponds toTYPE_TEXT_FLAG_AUTO_COMPLETE.
textMultiLine	0x00020001	Can be combined with text and its variations to allow multiple lines of text in the field. If this flag is not set, the text field will be constrained to a single line. Corresponds toTYPE_TEXT_FLAG_MULTI_LINE.
textImeMultiLine	0x00040001	Can be combined with text and its variations to indicate that though the regular text view should not be multiple lines, the IME should provide multiple lines if it can. Corresponds toTYPE_TEXT_FLAG_IME_MULTI_LINE.
textNoSuggestions	0x00080001	Can be combined with text and its variations to indicate that the IME should not show any dictionary-based word suggestions. Corresponds to TYPE_TEXT_FLAG_NO_SUGGESTIONS.
textUri	0x00000011	Text that will be used as a URI. Corresponds to TYPE_CLASS_TEXT | TYPE_TEXT_VARIATION_URI.
textEmailAddress	0x00000021	Text that will be used as an e-mail address. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_EMAIL_ADDRESS.
textEmailSubject	0x00000031	Text that is being supplied as the subject of an e-mail. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_EMAIL_SUBJECT.
textShortMessage	0x00000041	Text that is the content of a short message. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_SHORT_MESSAGE.
textLongMessage	0x00000051	Text that is the content of a long message. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_LONG_MESSAGE.
textPersonName	0x00000061	Text that is the name of a person. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_PERSON_NAME.
textPostalAddress	0x00000071	Text that is being supplied as a postal mailing address. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_POSTAL_ADDRESS.
textPassword	0x00000081	Text that is a password. Corresponds to TYPE_CLASS_TEXT | TYPE_TEXT_VARIATION_PASSWORD.
textVisiblePassword	0x00000091	Text that is a password that should be visible. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_VISIBLE_PASSWORD.
textWebEditText	0x000000a1	Text that is being supplied as text in a web form. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_WEB_EDIT_TEXT.
textFilter	0x000000b1	Text that is filtering some other data. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_FILTER.
textPhonetic	0x000000c1	Text that is for phonetic pronunciation, such as a phonetic name field in a contact entry. Corresponds to TYPE_CLASS_TEXT | TYPE_TEXT_VARIATION_PHONETIC.
textWebEmailAddress	0x000000d1	Text that will be used as an e-mail address on a web form. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_WEB_EMAIL_ADDRESS.
textWebPassword	0x000000e1	Text that will be used as a password on a web form. Corresponds to TYPE_CLASS_TEXT |TYPE_TEXT_VARIATION_WEB_PASSWORD.
number	0x00000002	A numeric only field. Corresponds to TYPE_CLASS_NUMBER | TYPE_NUMBER_VARIATION_NORMAL.
numberSigned	0x00001002	Can be combined with number and its other options to allow a signed number. Corresponds toTYPE_CLASS_NUMBER | TYPE_NUMBER_FLAG_SIGNED.
numberDecimal	0x00002002	Can be combined with number and its other options to allow a decimal (fractional) number. Corresponds to TYPE_CLASS_NUMBER | TYPE_NUMBER_FLAG_DECIMAL.
numberPassword	0x00000012	A numeric password field. Corresponds to TYPE_CLASS_NUMBER |TYPE_NUMBER_VARIATION_PASSWORD.
phone	0x00000003	For entering a phone number. Corresponds to TYPE_CLASS_PHONE.
datetime	0x00000004	For entering a date and time. Corresponds to TYPE_CLASS_DATETIME |TYPE_DATETIME_VARIATION_NORMAL.
date	0x00000014	For entering a date. Corresponds to TYPE_CLASS_DATETIME | TYPE_DATETIME_VARIATION_DATE.
time	0x00000024	For entering a time. Corresponds to TYPE_CLASS_DATETIME | TYPE_DATETIME_VARIATION_TIME.

This corresponds to the global attribute resource symbol inputType.

方式二：改变android.text.method.TransformationMethod 的值。

实现代码如下：

	
	/**
	 * 显示或隐藏
	 * @param isShow 
	 */
	private void showOrHide(boolean isShow){
		//记住光标开始的位置
		int pos = etPassword.getSelectionStart();
		if(isShow){
			etPassword.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
		}else{
			etPassword.setTransformationMethod(PasswordTransformationMethod.getInstance());
			
		}
		etPassword.setSelection(pos);
	}

参见：android.text.method.TransformationMethod