Android SpannableString(显示多样式文本)-白红宇

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

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。