Android SpannableString(显示多样式文本)
SpannableString与String相似，是一种字符串类型，TextView可以直接设置Spannable为显示文本，不相同的是，SpannableString可以使用setSpan方法实现字符串各种形式风格的显示，并且可以设置指定的区间。 setSpan(Object what, int start, int end, int flags)方法需要用户输入四个参数，what表示设置的格式是什么，可以是前景色、背景色也可以是可点击的文本等等(URLSpan、ClickableSpan、BackgroundColorSpan、ForegroundColorSpan、MaskFilterSpan、AbsoluteSizeSpan、RelativeSizeSpan、ImageSpan、ScaleXSpan、StyleSpan、SubscriptSpan、SuperscriptSpan、TextAppearanceSpan、TypefaceSpan、RasterizerSpan、StrikethroughSpan、UnderlineSpan)。MaskFilterSpan可以实现模糊和浮雕效果，RasterizerSpan可以实现光栅效果。start表示需要设置格式的子字符串的起始下标，同理end表示终了下标，flags属性就有意思了，共有四种属性： Spanned.SPAN_INCLUSIVE_INCLUSIVE：前后都包括 Spanned.SPAN_EXCLUSIVE_EXCLUSIVE：前后都不包括 Spanned.SPAN_INCLUSIVE_EXCLUSIVE：前面包括，后面不包括 Spanned.SPAN_EXCLUSIVE_INCLUSIVE：前面不包括，后面包括 SpannableStringBuilder实现对SpannableString的一个拼接效果，append()方法可以实现各种风格效果的SpannableString拼接，非常实用。 实例代码 activity.xml文件 <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:layout_marginTop="10dp" tools:context="com.mazaiting.spannablestring.MainActivity" > <TextView android:id="@+id/textView" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" /> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" > <Button android:onClick="foreGroundColor" android:text="前景色" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> <Button android:onClick="backGroundColor" android:text="背景色" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> <Button android:onClick="relativeSize" android:text="字体大小" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> <Button android:onClick="strikeThrough" android:text="删除线" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" > <Button android:onClick="underLine" android:text="下划线" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> <Button android:onClick="superScript" android:text="上标" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> <Button android:onClick="subScript" android:text="下标" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> <Button android:onClick="styleSpan" android:text="粗体斜体" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" > <Button android:onClick="imageSpan" android:text="图片" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> <Button android:onClick="click" android:text="点击" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> <Button android:onClick="urlSpan" android:text="URL" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> <Button android:onClick="styleSpan" android:text="粗体斜体" android:layout_weight="1" android:layout_width="0dp" android:layout_height="wrap_content" /> </LinearLayout> </LinearLayout> MainActivity.java代码 package com.mazaiting.spannablestring; import android.content.Intent; import android.graphics.Color; import android.graphics.Typeface; import android.graphics.drawable.Drawable; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.text.SpannableString; import android.text.Spanned; import android.text.TextPaint; import android.text.method.LinkMovementMethod; import android.text.style.BackgroundColorSpan; import android.text.style.ClickableSpan; import android.text.style.ForegroundColorSpan; import android.text.style.ImageSpan; import android.text.style.RelativeSizeSpan; import android.text.style.StrikethroughSpan; import android.text.style.StyleSpan; import android.text.style.SubscriptSpan; import android.text.style.SuperscriptSpan; import android.text.style.URLSpan; import android.text.style.UnderlineSpan; import android.util.TypedValue; import android.view.View; import android.widget.TextView; public class MainActivity extends AppCompatActivity { private TextView textView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); textView = (TextView) this.findViewById(R.id.textView); } /** * 设置前景色 */ public void foreGroundColor(View view){ SpannableString spannableString = new SpannableString("设置文字的前景色为淡蓝色"); ForegroundColorSpan foregroundColorSpan = new ForegroundColorSpan(Color.parseColor("#0099EE")); spannableString.setSpan(foregroundColorSpan, 9, spannableString.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE); textView.setText(spannableString); } /** * 设置背景色 */ public void backGroundColor(View view){ SpannableString spannableString = new SpannableString("设置文字的背景色为浅绿色"); BackgroundColorSpan backgroundColorSpan = new BackgroundColorSpan(Color.parseColor("#AC00FF30")); spannableString.setSpan(backgroundColorSpan, 9, spannableString.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE); textView.setText(spannableString); } /** * 设置文字大小 */ public void relativeSize(View view){ SpannableString spannableString = new SpannableString("万丈高楼平地起"); RelativeSizeSpan relativeSizeSpan1 = new RelativeSizeSpan(1.2f); RelativeSizeSpan relativeSizeSpan2 = new RelativeSizeSpan(1.4f); RelativeSizeSpan relativeSizeSpan3 = new RelativeSizeSpan(1.6f); RelativeSizeSpan relativeSizeSpan4 = new RelativeSizeSpan(1.8f); RelativeSizeSpan relativeSizeSpan5 = new RelativeSizeSpan(1.6f); RelativeSizeSpan relativeSizeSpan6 = new RelativeSizeSpan(1.4f); RelativeSizeSpan relativeSizeSpan7 = new RelativeSizeSpan(1.2f); spannableString.setSpan(relativeSizeSpan1, 0, 1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); spannableString.setSpan(relativeSizeSpan2, 1, 2, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); spannableString.setSpan(relativeSizeSpan3, 2, 3, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); spannableString.setSpan(relativeSizeSpan4, 3, 4, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); spannableString.setSpan(relativeSizeSpan5, 4, 5, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); spannableString.setSpan(relativeSizeSpan6, 5, 6, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); spannableString.setSpan(relativeSizeSpan7, 6, 7, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); textView.setText(spannableString); } /** * 设置删除线 */ public void strikeThrough(View view){ SpannableString spannableString = new SpannableString("为文字设置删除线"); StrikethroughSpan strikethroughSpan = new StrikethroughSpan(); spannableString.setSpan(strikethroughSpan, 5, spannableString.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE); textView.setText(spannableString); } /** * 设置下划线 */ public void underLine(View view){ SpannableString spannableString = new SpannableString("为文字设置下划线"); UnderlineSpan underlineSpan = new UnderlineSpan(); spannableString.setSpan(underlineSpan, 5, spannableString.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE); textView.setText(spannableString); } /** * 设置上标 */ public void superScript(View view){ SpannableString spannableString = new SpannableString("为文字设置上标"); SuperscriptSpan superscriptSpan = new SuperscriptSpan(); spannableString.setSpan(superscriptSpan, 5, spannableString.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE); textView.setText(spannableString); } /** * 设置下标 */ public void subScript(View view){ SpannableString spannableString = new SpannableString("为文字设置下标"); SubscriptSpan subscriptSpan = new SubscriptSpan(); spannableString.setSpan(subscriptSpan, 5, spannableString.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE); textView.setText(spannableString); } /** * 设置粗体斜体 */ public void styleSpan(View view){ SpannableString spannableString = new SpannableString("为文字设置粗体、斜体风格"); StyleSpan styleSpan_B = new StyleSpan(Typeface.BOLD); StyleSpan styleSpan_I = new StyleSpan(Typeface.ITALIC); spannableString.setSpan(styleSpan_B, 5, 7, Spanned.SPAN_INCLUSIVE_INCLUSIVE); spannableString.setSpan(styleSpan_I, 8, 10, Spanned.SPAN_INCLUSIVE_INCLUSIVE); textView.setText(spannableString); } /** * 设置图片 */ public void imageSpan(View view){ SpannableString spannableString = new SpannableString("在文本中添加表情(表情)"); Drawable drawable = getResources().getDrawable(R.mipmap.emotion); drawable.setBounds(0, 0, 42, 42); ImageSpan imageSpan = new ImageSpan(drawable); spannableString.setSpan(imageSpan, 6, 8, Spanned.SPAN_INCLUSIVE_EXCLUSIVE); textView.setText(spannableString); } /** * 点击开启新界面 */ public void click(View view){ SpannableString spannableString = new SpannableString("为文字设置点击事件"); MyClickableSpan clickableSpan = new MyClickableSpan("http://www.jianshu.com/"); spannableString.setSpan(clickableSpan, 5, spannableString.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE); // 使用ClickableSpan的文本如果想真正实现点击作用， // 必须为TextView设置setMovementMethod方法，否则没有点击相应， // 至于setHighlightColor方法则是控制点击是的背景色。 textView.setMovementMethod(LinkMovementMethod.getInstance()); textView.setHighlightColor(Color.parseColor("#36969696")); textView.setText(spannableString); } class MyClickableSpan extends ClickableSpan { private String content; public MyClickableSpan(String content) { this.content = content; } @Override public void updateDrawState(TextPaint ds) { ds.setUnderlineText(false); } @Override public void onClick(View widget) { Intent intent = new Intent(MainActivity.this, SecondActivity.class); Bundle bundle = new Bundle(); bundle.putString("content", content); intent.putExtras(bundle); startActivity(intent); } } /** * 网络链接 */ public void urlSpan(View view) { SpannableString spannableString = new SpannableString("为文字设置超链接"); URLSpan urlSpan = new URLSpan("http://www.jianshu.com/"); spannableString.setSpan(urlSpan, 5, spannableString.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE); textView.setMovementMethod(LinkMovementMethod.getInstance()); textView.setHighlightColor(Color.parseColor("#36969696")); textView.setText(spannableString); } } 注: 文章中涉及到的Activity即一个空的Activity, 读者可以可以新建一个空界面即可。
