Android UI系列：TextView显示文本

Android下有众多的Widget，而TextView可以说是最基础的，或者说是最基本的的控件。和其它编程语言相同的label标签一样，一般用来显示固定长度的文本字符串。

一、实例

在介绍前先演示一下实例

效果图一如上

布局文件text_view.xml

java代码TextViewActivity.java

package com.example.test;

import android.app.Activity;
import android.os.Bundle;

public class TextViewActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.text_view);
	}
}

再在AndroidManifest.xml配置一下

其中用的字符串资源是

我是Textview，大家要好好学习！

二、TextView类结构

java.lang.Object
   ↳     android.view.View
         ↳     android.widget.TextView

直接子类
Button, CheckedTextView, Chronometer, DigitalClock, EditText, TextClock

间接子类
AutoCompleteTextView, CheckBox, CompoundButton, ExtractEditText, MultiAutoCompleteTextView, RadioButton, Switch, ToggleButton 

Button，EditText，CheckBox，RadioButton，ToggleButton 等都是它的直接子类或间接子类，所以我们要一定学好TextView，才能更好地学习其它控件。

三、TextView属性

XML Attributes
Attribute Name	Related Method	Description
android:autoLink	setAutoLinkMask(int)	Controls whether links such as urls and email addresses are automatically found and converted to clickable links.
android:autoText	setKeyListener(KeyListener)	If set, specifies that this TextView has a textual input method and automatically corrects some common spelling errors.
android:bufferType	setText(CharSequence,TextView.BufferType)	Determines the minimum type that getText() will return.
android:capitalize	setKeyListener(KeyListener)	If set, specifies that this TextView has a textual input method and should automatically capitalize what the user types.
android:cursorVisible	setCursorVisible(boolean)	Makes the cursor visible (the default) or invisible.
android:digits	setKeyListener(KeyListener)	If set, specifies that this TextView has a numeric input method and that these specific characters are the ones that it will accept.
android:drawableBottom	setCompoundDrawablesWithIntrinsicBounds(int,int,int,int)	The drawable to be drawn below the text.
android:drawableEnd	setCompoundDrawablesRelativeWithIntrinsicBounds(int,int,int,int)	The drawable to be drawn to the end of the text.
android:drawableLeft	setCompoundDrawablesWithIntrinsicBounds(int,int,int,int)	The drawable to be drawn to the left of the text.
android:drawablePadding	setCompoundDrawablePadding(int)	The padding between the drawables and the text.
android:drawableRight	setCompoundDrawablesWithIntrinsicBounds(int,int,int,int)	The drawable to be drawn to the right of the text.
android:drawableStart	setCompoundDrawablesRelativeWithIntrinsicBounds(int,int,int,int)	The drawable to be drawn to the start of the text.
android:drawableTop	setCompoundDrawablesWithIntrinsicBounds(int,int,int,int)	The drawable to be drawn above the text.
android:editable		If set, specifies that this TextView has an input method.
android:editorExtras	setInputExtras(int)	Reference to an XML resource containing additional data to supply to an input method, which is private to the implementation of the input method.
android:ellipsize	setEllipsize(TextUtils.TruncateAt)	If set, causes words that are longer than the view is wide to be ellipsized instead of broken in the middle.
android:ems	setEms(int)	Makes the TextView be exactly this many ems wide.
android:fontFamily	setTypeface(Typeface)	Font family (named by string) for the text.
android:freezesText	setFreezesText(boolean)	If set, the text view will include its current complete text inside of its frozen icicle in addition to meta-data such as the current cursor position.
android:gravity	setGravity(int)	Specifies how to align the text by the view's x- and/or y-axis when the text is smaller than the view.
android:height	setHeight(int)	Makes the TextView be exactly this many pixels tall.
android:hint	setHint(int)	Hint text to display when the text is empty.
android:imeActionId	setImeActionLabel(CharSequence,int)	Supply a value for EditorInfo.actionId used when an input method is connected to the text view.
android:imeActionLabel	setImeActionLabel(CharSequence,int)	Supply a value for EditorInfo.actionLabel used when an input method is connected to the text view.
android:imeOptions	setImeOptions(int)	Additional features you can enable in an IME associated with an editor to improve the integration with your application.
android:includeFontPadding	setIncludeFontPadding(boolean)	Leave enough room for ascenders and descenders instead of using the font ascent and descent strictly.
android:inputMethod	setKeyListener(KeyListener)	If set, specifies that this TextView should use the specified input method (specified by fully-qualified class name).
android:inputType	setRawInputType(int)	The type of data being placed in a text field, used to help an input method decide how to let the user enter text.
android:lineSpacingExtra	setLineSpacing(float,float)	Extra spacing between lines of text.
android:lineSpacingMultiplier	setLineSpacing(float,float)	Extra spacing between lines of text, as a multiplier.
android:lines	setLines(int)	Makes the TextView be exactly this many lines tall.
android:linksClickable	setLinksClickable(boolean)	If set to false, keeps the movement method from being set to the link movement method even if autoLink causes links to be found.
android:marqueeRepeatLimit	setMarqueeRepeatLimit(int)	The number of times to repeat the marquee animation.
android:maxEms	setMaxEms(int)	Makes the TextView be at most this many ems wide.
android:maxHeight	setMaxHeight(int)	Makes the TextView be at most this many pixels tall.
android:maxLength	setFilters(InputFilter)	Set an input filter to constrain the text length to the specified number.
android:maxLines	setMaxLines(int)	Makes the TextView be at most this many lines tall.
android:maxWidth	setMaxWidth(int)	Makes the TextView be at most this many pixels wide.
android:minEms	setMinEms(int)	Makes the TextView be at least this many ems wide.
android:minHeight	setMinHeight(int)	Makes the TextView be at least this many pixels tall.
android:minLines	setMinLines(int)	Makes the TextView be at least this many lines tall.
android:minWidth	setMinWidth(int)	Makes the TextView be at least this many pixels wide.
android:numeric	setKeyListener(KeyListener)	If set, specifies that this TextView has a numeric input method.
android:password	setTransformationMethod(TransformationMethod)	Whether the characters of the field are displayed as password dots instead of themselves.
android:phoneNumber	setKeyListener(KeyListener)	If set, specifies that this TextView has a phone number input method.
android:privateImeOptions	setPrivateImeOptions(String)	An addition content type description to supply to the input method attached to the text view, which is private to the implementation of the input method.
android:scrollHorizontally	setHorizontallyScrolling(boolean)	Whether the text is allowed to be wider than the view (and therefore can be scrolled horizontally).
android:selectAllOnFocus	setSelectAllOnFocus(boolean)	If the text is selectable, select it all when the view takes focus.
android:shadowColor	setShadowLayer(float,float,float,int)	Place a shadow of the specified color behind the text.
android:shadowDx	setShadowLayer(float,float,float,int)	Horizontal offset of the shadow.
android:shadowDy	setShadowLayer(float,float,float,int)	Vertical offset of the shadow.
android:shadowRadius	setShadowLayer(float,float,float,int)	Radius of the shadow.
android:singleLine	setTransformationMethod(TransformationMethod)	Constrains the text to a single horizontally scrolling line instead of letting it wrap onto multiple lines, and advances focus instead of inserting a newline when you press the enter key.
android:text	setText(CharSequence,TextView.BufferType)	Text to display.
android:textAllCaps	setAllCaps(boolean)	Present the text in ALL CAPS.
android:textAppearance		Base text color, typeface, size, and style.
android:textColor	setTextColor(int)	Text color.
android:textColorHighlight	setHighlightColor(int)	Color of the text selection highlight.
android:textColorHint	setHintTextColor(int)	Color of the hint text.
android:textColorLink	setLinkTextColor(int)	Text color for links.
android:textIsSelectable	isTextSelectable()	Indicates that the content of a non-editable text can be selected.
android:textScaleX	setTextScaleX(float)	Sets the horizontal scaling factor for the text.
android:textSize	setTextSize(int,float)	Size of the text.
android:textStyle	setTypeface(Typeface)	Style (bold, italic, bolditalic) for the text.
android:typeface	setTypeface(Typeface)	Typeface (normal, sans, serif, monospace) for the text.
android:width	setWidth(int)	Makes the TextView be exactly this many pixels wide.

四、能过代码方式建立TextView

TextView可以通过在布局文件进行设置，也可以通过代码生成

@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		TextView textView= new TextView(this);
		textView.setText(getText(R.string.textView_content));
		
		setContentView(textView);
	}

运行的效果和图一完全一样

五、走马灯效果

        android:ellipsize="marquee"
        android:focusable="true"
        android:focusableInTouchMode="true"
        android:marqueeRepeatLimit="marquee_forever"
        android:singleLine="true"

加上以上属性就可以实现走马灯的效果了

注意：

1.要单行，如果没有设置单行，多行可以全部显示出来，是没有走马灯的效果的

2.设置为焦点

3没有滚动球的设备 android:focusableInTouchMode="true"属性是必须的

4.如果内容一行就可以显示出来的，请重复一次内容，如果重复后还是可以一行显示的，请再重复，如

 我是Textview，大家要好好学习！我是Textview，大家要好好学习！

闪烁效果

别人的走马灯效果要闪烁一下，那我们也来实现

public class TextViewActivity extends Activity {
	private TextView textView = null;
	private boolean changeColor = false;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.text_view);
		textView = (TextView) findViewById(R.id.text_view);

		new Thread(new MyThread()).start();

	}

	//实现半秒就改变一次颜色
	class MyThread implements Runnable {
		@Override
		public void run() {
			//传说中死循环，半秒就改变一次
			while (true) {
				try {
					Thread.sleep(500);
				} catch (InterruptedException e) {
					e.printStackTrace();
				}

				Message message = new Message();
				if (changeColor = !changeColor) {
					message.what = COLOR_BLACK;
				} else {
					message.what = COLOR_RED;
				}
				handler.sendMessage(message);
			}
		}// end run

	}

	private final int COLOR_RED = 1;//红色
	private final int COLOR_BLACK = 2;//黑色
	private MyHandler handler = new MyHandler();

	class MyHandler extends Handler {
		@Override
		public void handleMessage(Message msg) {
			switch (msg.what) {
			case COLOR_RED:
				textView.setTextColor(Color.RED);
				break;
			case COLOR_BLACK:
				textView.setTextColor(Color.BLACK);
				break;

			default:
				break;
			}
		}
	}
}

以上的效果是半秒就改变一下字体的颜色，红黑不停地切换

六、在文本中创建上下文链接

如果TextView中的文本字符串包含有网址、邮箱、电话号码或地址，是否可以点击进行相应的跳转到我们要去的页面，如字符串的网址链接，跳到相应的网页，那样我们就可以直接查看内容了，这不是一件很美妙的事吗?

答案是确定的，我们可以对android:autoLink属性进行设置，或者调用 setAutoLinkMask(int)方法

Must be one or more (separated by '|') of the following constant values.

Constant	Value	Description
none	0x00	都不匹配 (default).
web	0x01	匹配网址链接
email	0x02	匹配email地址
phone	0x04	匹配电话号码
map	0x08	匹配地图地址.
all	0x0f	匹配所有(equivalent to web|email|phone|map).

例如xml设置

android:autoLink="web" 

android:autoLink="web|email"

android:autoLink="all"

java代码设置

textView.setAutoLinkMask(Linkify.EMAIL_ADDRESSES);

textView.setAutoLinkMask(Linkify.EMAIL_ADDRESSES|Linkify.WEB_URLS);

textView.setAutoLinkMask(Linkify.ALL);

七、获取本地资源及格式化

方法1

 public final CharSequence getText (int resId)

Return a localized, styled CharSequence from the application's package's default string table.

方法2

 public final String getString (int resId)

Return a localized string from the application's package's default string table.

方法3

getResources().getString(int resId)

Return the string value associated with a particular resource ID. It will be stripped of any styled text information.

演示：

Plain, bold, italic, bold-italic

text_view_1.setText(getText(R.string.text_format));
text_view_2.setText(getString(R.string.text_format));
text_view_3.setText(getResources().getString(R.string.text_format));

TextView 也可以支持html格式显示

主要是使用Html.fromHtml(String str)方法

String htmlStr="我是中国人。
我你他也是中国人呀。";
text_view_4.setText(Html.fromHtml(htmlStr));

string.xml特殊字符

string.xml中有特殊的字符，会报错的，那应该怎样解决呢

一个方法是用转义符，还有一个更简单的方法就是用形式

string.xml字符串中带参数

我是%1$s,我的年龄是%2$d

text_view_5.setText(getString(R.string.textview_param, "科学家",20));

结果显示：我是科学家，我的年龄是

%1$s       1表示第一个参数，s表示为字符串

%2$d      2表示第二个参数，d表示为数字，整数、小数都可以

八、显示图片

上图是android桌面上的应用图标，应用名称上面是应用logo，这个怎样的实现的

是不是用了两个控件，一个是ImageView，另一个是TextView

其实不是，真正实现只是用了一个TextView

android:drawableTop表示是textView上面显示图片

android:drawableBottom表示底部显示图片

android:drawableLeft表示左边显示图片

android:drawableRight表示右边显示图片

九、属性介绍

android:ellipsize

内容过长时，可以加省略号
android:ellipsize = "none"　　默认值，没有省略号
android:ellipsize = "end"　　  省略号在结尾 
android:ellipsize = "start" 　　省略号在开头 
android:ellipsize = "middle"    省略号在中间 
android:ellipsize = "marquee"  跑马灯 

注意要加行数限制，要不省略号不起作用

如 android:maxLines="2" 超过两行将出现省略号

或者android:singleLine="true"限制为1行