android中SpannableString之富文本显示效果

SpannableString其实和String一样，都是一种字符串类型，SpannableString可以直接作为TextView的显示文本，不同的是SpannableString可以通过使用其方法setSpan方法实现字符串各种形式风格的显示,重要的是可以指定设置的区间，也就是为字符串指定下标区间内的子字符串设置格式。

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，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_EXCLUSIVE 从起始下标到终了下标，包括起始下标
Spanned.SPAN_INCLUSIVE_INCLUSIVE 从起始下标到终了下标，同时包括起始下标和终了下标
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE 从起始下标到终了下标，但都不包括起始下标和终了下标
Spanned.SPAN_EXCLUSIVE_INCLUSIVE 从起始下标到终了下标，包括终了下标

SpannableString的setSpan()方法可以同时使用多个，实现多种效果叠加。

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package com.loaderman.androiddemo;

import android.content.Intent;
import android.graphics.Color;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
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.view.View;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView tv1 = findViewById(R.id.tv1);
        TextView tv2 = findViewById(R.id.tv2);
        TextView tv3 = findViewById(R.id.tv3);
        TextView tv4 = findViewById(R.id.tv4);
        TextView tv5 = findViewById(R.id.tv5);
        TextView tv6 = findViewById(R.id.tv6);
        TextView tv7 = findViewById(R.id.tv7);
        TextView tv8 = findViewById(R.id.tv8);
        TextView tv9 = findViewById(R.id.tv9);
        TextView tv10 = findViewById(R.id.tv10);
        TextView tv11 = findViewById(R.id.tv11);

        //设置字体前景色
        SpannableString spannableString1 = new SpannableString("设置文字的前景色为淡蓝色");
        ForegroundColorSpan colorSpan1 = new ForegroundColorSpan(Color.parseColor("#0099EE"));
        spannableString1.setSpan(colorSpan1, 9, spannableString1.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv1.setText(spannableString1);
        //设置字体背景色
        SpannableString spannableString2 = new SpannableString("设置文字的背景色为淡绿色");
        BackgroundColorSpan colorSpan2 = new BackgroundColorSpan(Color.parseColor("#AC00FF30"));
        spannableString2.setSpan(colorSpan2, 9, spannableString2.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv2.setText(spannableString2);
        //设置字体大小
        SpannableString spannableString3 = new SpannableString("万丈高楼平地起");
        RelativeSizeSpan sizeSpan01 = new RelativeSizeSpan(1.2f);
        RelativeSizeSpan sizeSpan02 = new RelativeSizeSpan(1.4f);
        RelativeSizeSpan sizeSpan03 = new RelativeSizeSpan(1.6f);
        RelativeSizeSpan sizeSpan04 = new RelativeSizeSpan(1.8f);
        RelativeSizeSpan sizeSpan05 = new RelativeSizeSpan(1.6f);
        RelativeSizeSpan sizeSpan06 = new RelativeSizeSpan(1.4f);
        RelativeSizeSpan sizeSpan07 = new RelativeSizeSpan(1.2f);
        spannableString3.setSpan(sizeSpan01, 0, 1, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        spannableString3.setSpan(sizeSpan02, 1, 2, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        spannableString3.setSpan(sizeSpan03, 2, 3, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        spannableString3.setSpan(sizeSpan04, 3, 4, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        spannableString3.setSpan(sizeSpan05, 4, 5, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        spannableString3.setSpan(sizeSpan06, 5, 6, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        spannableString3.setSpan(sizeSpan07, 6, 7, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv3.setText(spannableString3);
        //设置删除线
        SpannableString spannableString4 = new SpannableString("为文字设置删除线");
        StrikethroughSpan strikethroughSpan4 = new StrikethroughSpan();
        spannableString4.setSpan(strikethroughSpan4, 5, spannableString4.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv4.setText(spannableString4);
        //设置下划线
        SpannableString spannableString5 = new SpannableString("为文字设置下划线");
        UnderlineSpan underlineSpan5 = new UnderlineSpan();
        spannableString5.setSpan(underlineSpan5, 5, spannableString5.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv5.setText(spannableString5);
        //设置上标
        SpannableString spannableString6 = new SpannableString("为文字设置上标");
        SuperscriptSpan superscriptSpan6 = new SuperscriptSpan();
        spannableString6.setSpan(superscriptSpan6, 5, spannableString6.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv6.setText(spannableString6);
        // 设置下标
        SpannableString spannableString7 = new SpannableString("为文字设置下标");
        SubscriptSpan subscriptSpan7 = new SubscriptSpan();
        spannableString7.setSpan(subscriptSpan7, 5, spannableString7.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv7.setText(spannableString7);
        //设置粗体和斜体
        SpannableString spannableString8 = 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);
        spannableString8.setSpan(styleSpan_B, 5, 7, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        spannableString8.setSpan(styleSpan_I, 8, 10, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv8.setHighlightColor(Color.parseColor("#36969696"));
        tv8.setText(spannableString8);
        //设置图片表情等
        SpannableString spannableString9 = new SpannableString("在文本中添加表情（表情）");
        Drawable drawable9 = getResources().getDrawable(R.mipmap.a9c);
        drawable9.setBounds(0, 0, 42, 42);
        ImageSpan imageSpan9 = new ImageSpan(drawable9);
        spannableString9.setSpan(imageSpan9, 6, 8, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv9.setText(spannableString9);
        //设置点击事件
        SpannableString spannableString10 = new SpannableString("为文字设置点击事件");
        MyClickableSpan clickableSpan = new MyClickableSpan("https://www.cnblogs.com/loaderman/");
        spannableString10.setSpan(clickableSpan, 5, spannableString10.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv10.setMovementMethod(LinkMovementMethod.getInstance());
        tv10.setHighlightColor(Color.parseColor("#36969696"));
        tv10.setText(spannableString10);
        //设置超链接
        SpannableString spannableString11 = new SpannableString("为文字设置超链接");
        URLSpan urlSpan11 = new URLSpan("https://www.cnblogs.com/loaderman/");
        spannableString11.setSpan(urlSpan11, 5, spannableString11.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
        tv11.setMovementMethod(LinkMovementMethod.getInstance());
        tv11.setHighlightColor(Color.parseColor("#36969696"));
        tv11.setText(spannableString11);
    }

    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, OtherActivity.class);
            Bundle bundle = new Bundle();
            bundle.putString("content", content);
            intent.putExtra("bundle", bundle);
            startActivity(intent);
        }
    }
}

效果