序言

在最近的項(xiàng)目中需要實(shí)現(xiàn)行內(nèi)標(biāo)簽，我原來覺得挺簡(jiǎn)單的后來,后來試了很多方式發(fā)現(xiàn)并沒有那么簡(jiǎn)單。比如想到的幾種實(shí)現(xiàn)方式和最終的效果如下圖，本著辛苦我一個(gè)方便千萬家的思想，我把我的TagUtil抽取出來了，并上傳到GitHub上了。

這里寫圖片描述

實(shí)現(xiàn)思路

1.首先需要一個(gè)tag的布局文件

這里寫圖片描述

2.手動(dòng)的填充布局文件，生成一個(gè)TextView
3.根據(jù)這個(gè)TextView獲取它的截屏，生成一個(gè)Bitmap
4.將bitmap設(shè)置到需要顯示tag的TextView上，這和TextView中顯示表情的原理是一樣的。

代碼如下

package com.trs.nxnews.news.util;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.text.SpannableString;
import android.text.TextUtils;
import android.text.style.ImageSpan;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.TextView;

import com.trs.nxnews.R;

import static android.text.Spanned.SPAN_INCLUSIVE_EXCLUSIVE;

/**
 * Created by zhuguohui on 2016/12/12.
 */

public class TagUtil {
    public static void setTag(String tag, TextView textView) {
        if (TextUtils.isEmpty(tag) || "無".equals(tag)) {
            return;
        }
        //填充tag布局
        TextView tv_tag = (TextView) LayoutInflater.from(textView.getContext()).inflate(R.layout.view_tag, null, true);
        tv_tag.setText(tag);

        //獲取View的截圖，用來當(dāng)Tag圖標(biāo)
        Bitmap drawingCache = convertViewToBitmap(tv_tag);

        //將圖片設(shè)置到TextView中
        BitmapDrawable bitmapDrawable = new BitmapDrawable(drawingCache);
        bitmapDrawable.setBounds(0, 0, drawingCache.getWidth(), drawingCache.getHeight());
        SpannableString spannableString = new SpannableString(tag + textView.getText());
        MyIm imageSpan = new MyIm(bitmapDrawable);
        spannableString.setSpan(imageSpan, 0, tag.length(), SPAN_INCLUSIVE_EXCLUSIVE);
        textView.setText(spannableString);
    }

    /**
     * 獲取tag圖標(biāo)
     *
     * @param view
     * @return
     */
    public static Bitmap convertViewToBitmap(View view) {
        view.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED), View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
        view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
        view.buildDrawingCache();
        Bitmap bitmap = view.getDrawingCache();
        return bitmap;
    }

    /**
     * 可以居中對(duì)齊的ImageSPan
     */
    public static class MyIm extends ImageSpan {
        public MyIm(Context arg0, int arg1) {
            super(arg0, arg1);
        }

        public MyIm(Drawable drawable) {
            super(drawable);
        }

        public int getSize(Paint paint, CharSequence text, int start, int end,
                           Paint.FontMetricsInt fm) {
            Drawable d = getDrawable();
            Rect rect = d.getBounds();
            if (fm != null) {
                Paint.FontMetricsInt fmPaint = paint.getFontMetricsInt();
                int fontHeight = fmPaint.bottom - fmPaint.top;
                int drHeight = rect.bottom - rect.top;

                int top = drHeight / 2 - fontHeight / 4;
                int bottom = drHeight / 2 + fontHeight / 4;

                fm.ascent = -bottom;
                fm.top = -bottom;
                fm.bottom = top;
                fm.descent = top;
            }
            //15為padding
            return rect.right + 15;
        }

        @Override
        public void draw(Canvas canvas, CharSequence text, int start, int end,
                         float x, int top, int y, int bottom, Paint paint) {
            Drawable b = getDrawable();
            canvas.save();
            int transY = 0;
            transY = ((bottom - top) - b.getBounds().bottom) / 2 + top;
            canvas.translate(x, transY);
            b.draw(canvas);
            canvas.restore();
        }
    }
}

源碼

TAGDemo

總結(jié)

有一些事情并沒有想象中那么簡(jiǎn)單，多積累一點(diǎn)一滴的技術(shù)，學(xué)會(huì)靈活運(yùn)用技術(shù)，這樣開發(fā)才會(huì)越來越簡(jiǎn)單，與君共勉。