点击可展开的TextView-白红宇

点击可展开的TextView

阅读量：5050 次

发布时间：2019-06-12

本文共 11579 字，大约阅读时间需要 38 分钟。

自定义TextView

1 package com.sun.mytext;  2   3 import android.annotation.SuppressLint;  4 import android.content.Context;  5 import android.os.Build;  6 import android.text.Layout;  7 import android.text.SpannableString;  8 import android.text.Spanned;  9 import android.text.StaticLayout; 10 import android.text.method.LinkMovementMethod; 11 import android.util.AttributeSet; 12 import android.view.View; 13 import android.widget.TextView; 14  15 /** 16  * @author Sigal 17  * on 2018/12/18 18  * note: 可展开的TextView 19  */ 20 @SuppressLint("AppCompatCustomView") 21 public class ExpandTextView extends TextView { 22     // 原始内容文本 23     private String originText; 24     // TextView可展示宽度 25     private int initWidth = 0; 26     // TextView最大行数 27     private int mMaxLines = 3; 28     // 收起的文案(颜色处理) 29     private SpannableString SPAN_CLOSE = null; 30     // 展开的文案(颜色处理) 31     private SpannableString SPAN_EXPAND = null; 32     private String TEXT_EXPAND = "  查看更多>"; 33     private String TEXT_CLOSE = "  
     <收起"; 34 35 public expandtextview(context context) { 36 super(context); 37 initcloseend(); 38 } 39 40 context, attributeset attrs) 41 super(context, attrs); 42 43 44 45 attrs, int defstyleattr) 46 defstyleattr); 47 48 49 50 ** 51 * 设置textview可显示的最大行数 52 @param maxlines 最大行数 53 54 @override 55 void setmaxlines(int maxlines) 56 this.mmaxlines="maxLines;" 57 super.setmaxlines(maxlines); 58 59 60 61 初始化textview的可展示宽度 62 width 63 64 initwidth(int width){ 65 initwidth="width;" 66 67 68 69 收起的文案(颜色处理)初始化 70 71 private initcloseend(){ 72 string content="TEXT_CLOSE;" 73 span_close="new" spannablestring(content); 74 buttonspan span="new" buttonspan(getcontext(), new view.onclicklistener(){ 75 76 onclick(view v) 77 expandtextview.super.setmaxlines(integer.max_value); 78 setexpandtext(origintext); 79 80 }, r.color.coloraccent); 81 span_close.setspan(span, 0, content.length(), spanned.span_inclusive_exclusive); 82 83 84 85 展开的文案(颜色处理)初始化 86 87 initexpandend(){ 88 89 span_expand="new" 90 91 92 93 expandtextview.super.setmaxlines(mmaxlines); 94 setclosetext(origintext); 95 96 97 span_expand.setspan(span, 98 99 100 setclosetext(charsequence text) {101 102 if(span_close="=" null){103 initcloseend();104 }105 boolean appendshowall="false;//" true 不需要展开收起功能， false 需要展开收起功能106 origintext="text.toString();107" 108 sdk>
      = 16 可以直接从xml属性获取最大行数109         int maxLines = 0;110         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.JELLY_BEAN) {111             maxLines = getMaxLines();112         } else{113             maxLines = mMaxLines;114         }115         String workingText = new StringBuilder(originText).toString();116         if (maxLines != -1) {117             Layout layout = createWorkingLayout(workingText);118             if (layout.getLineCount() > maxLines) {119                 //获取一行显示字符个数，然后截取字符串数120                 workingText = originText.substring(0, layout.getLineEnd(maxLines - 1)).trim();// 收起状态原始文本截取展示的部分121                 String showText = originText.substring(0, layout.getLineEnd(maxLines - 1)).trim() + "..." + SPAN_CLOSE;122                 Layout layout2 = createWorkingLayout(showText);123                 // 对workingText进行-1截取，直到展示行数==最大行数，并且添加 SPAN_CLOSE 后刚好占满最后一行124                 while (layout2.getLineCount() > maxLines) {125                     int lastSpace = workingText.length()-1;126                     if (lastSpace == -1) {127                         break;128                     }129                     workingText = workingText.substring(0, lastSpace);130                     layout2 = createWorkingLayout(workingText + "..." + SPAN_CLOSE);131                 }132                 appendShowAll = true;133                 workingText = workingText + "...";134             }135         }136 137         setText(workingText);138         if (appendShowAll) {139             // 必须使用append，不能在上面使用+连接，否则spannable会无效140             append(SPAN_CLOSE);141             setMovementMethod(LinkMovementMethod.getInstance());142         }143     }144 145     public void setExpandText(String text) {146         if(SPAN_EXPAND == null){147             initExpandEnd();148         }149         Layout layout1 = createWorkingLayout(text);150         Layout layout2 = createWorkingLayout(text + TEXT_CLOSE);151         // 展示全部原始内容时 如果 TEXT_CLOSE 需要换行才能显示完整，则直接将TEXT_CLOSE展示在下一行152         if(layout2.getLineCount() > layout1.getLineCount()){153             setText(originText + "\n");154         }else{155             setText(originText);156         }157         append(SPAN_EXPAND);158         setMovementMethod(LinkMovementMethod.getInstance());159     }160 161     //返回textview的显示区域的layout，该textview的layout并不会显示出来，只是用其宽度来比较要显示的文字是否过长162     private Layout createWorkingLayout(String workingText) {163         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {164             return new StaticLayout(workingText, getPaint(), initWidth - getPaddingLeft() - getPaddingRight(),165                     Layout.Alignment.ALIGN_NORMAL, getLineSpacingMultiplier(), getLineSpacingExtra(), false);166         } else{167             return new StaticLayout(workingText, getPaint(), initWidth - getPaddingLeft() - getPaddingRight(),168                     Layout.Alignment.ALIGN_NORMAL, 1.0f, 0.0f, false);169         }170     }171 }

自定义ClickableSpan

1 package com.sun.mytext; 2  3 import android.content.Context; 4 import android.text.TextPaint; 5 import android.text.style.ClickableSpan; 6 import android.view.View; 7  8 /** 9  * @author Sigal10  * on 2018/12/1811  * note:12  */13 public class ButtonSpan extends ClickableSpan {14     View.OnClickListener onClickListener;15     private Context context;16     private int colorId;17 18     public ButtonSpan(Context context, View.OnClickListener onClickListener) {19         this(context, onClickListener, R.color.textColor);20     }21 22     public ButtonSpan(Context context, View.OnClickListener onClickListener, int colorId){23         this.onClickListener = onClickListener;24         this.context = context;25         this.colorId = colorId;26     }27 28     @Override29     public void updateDrawState(TextPaint ds) {30         ds.setColor(context.getResources().getColor(colorId));31         ds.setUnderlineText(false);32     }33 34     @Override35     public void onClick(View widget) {36         if (onClickListener != null) {37             onClickListener.onClick(widget);38         }39     }40 41 }

PxUtils 和 ScreenUtils

1 package com.sun.mytext; 2  3 import android.content.Context; 4  5 /** 6  * @author Sigal 7  * on 2018/12/18 8  * note: px与dp、sp的转换 9  */10 public class PxUtils {11     /**12      * 将px转换为与之相等的dp13      */14     public static int px2dp(Context context, float pxValue) {15         final float scale =  context.getResources().getDisplayMetrics().density;16         return (int) (pxValue / scale + 0.5f);17     }18 19     /**20      * 将dp转换为与之相等的px21      */22     public static int dp2px(Context context, float dipValue) {23         final float scale = context.getResources().getDisplayMetrics().density;24         return (int) (dipValue * scale + 0.5f);25     }26 27     /**28      * 将px转换为sp29      */30     public static int px2sp(Context context, float pxValue) {31         final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;32         return (int) (pxValue / fontScale + 0.5f);33     }34 35     /**36      * 将sp转换为px37      */38     public static int sp2px(Context context, float spValue) {39         final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;40         return (int) (spValue * fontScale + 0.5f);41     }42 43 }

1 package com.sun.mytext;  2   3 import android.app.Activity;  4 import android.content.Context;  5 import android.graphics.Bitmap;  6 import android.graphics.Rect;  7 import android.util.DisplayMetrics;  8 import android.view.View;  9 import android.view.WindowManager; 10  11 /** 12  * @author Sigal 13  * on 2018/12/18 14  * note: 15  */ 16 public class ScreenUtils { 17     private ScreenUtils() 18     { 19         /* cannot be instantiated */ 20         throw new UnsupportedOperationException("cannot be instantiated"); 21     } 22  23     /** 24      * 获得屏幕高度 25      * @param context 26      * @return 27      */ 28     public static int getScreenWidth(Context context) 29     { 30         WindowManager wm = (WindowManager) context 31                 .getSystemService(Context.WINDOW_SERVICE); 32         DisplayMetrics outMetrics = new DisplayMetrics(); 33         wm.getDefaultDisplay().getMetrics(outMetrics); 34         return outMetrics.widthPixels; 35     } 36  37     /** 38      * 获得屏幕宽度 39      * @param context 40      * @return 41      */ 42     public static int getScreenHeight(Context context) 43     { 44         WindowManager wm = (WindowManager) context 45                 .getSystemService(Context.WINDOW_SERVICE); 46         DisplayMetrics outMetrics = new DisplayMetrics(); 47         wm.getDefaultDisplay().getMetrics(outMetrics); 48         return outMetrics.heightPixels; 49     } 50  51     /** 52      * 获得状态栏的高度 53      * @param context 54      * @return 55      */ 56     public static int getStatusHeight(Context context) 57     { 58  59         int statusHeight = -1; 60         try 61         { 62             Class
      clazz = Class.forName("com.android.internal.R$dimen"); 63             Object object = clazz.newInstance(); 64             int height = Integer.parseInt(clazz.getField("status_bar_height") 65                     .get(object).toString()); 66             statusHeight = context.getResources().getDimensionPixelSize(height); 67         } catch (Exception e) 68         { 69             e.printStackTrace(); 70         } 71         return statusHeight; 72     } 73  74     /** 75      * 获取当前屏幕截图，包含状态栏 76      * @param activity 77      * @return 78      */ 79     public static Bitmap snapShotWithStatusBar(Activity activity) 80     { 81         View view = activity.getWindow().getDecorView(); 82         view.setDrawingCacheEnabled(true); 83         view.buildDrawingCache(); 84         Bitmap bmp = view.getDrawingCache(); 85         int width = getScreenWidth(activity); 86         int height = getScreenHeight(activity); 87         Bitmap bp = null; 88         bp = Bitmap.createBitmap(bmp, 0, 0, width, height); 89         view.destroyDrawingCache(); 90         return bp; 91  92     } 93  94     /** 95      * 获取当前屏幕截图，不包含状态栏 96      * @param activity 97      * @return 98      */ 99     public static Bitmap snapShotWithoutStatusBar(Activity activity) {100         View view = activity.getWindow().getDecorView();101         view.setDrawingCacheEnabled(true);102         view.buildDrawingCache();103         Bitmap bmp = view.getDrawingCache();104         Rect frame = new Rect();105         activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);106         int statusBarHeight = frame.top;107 108         int width = getScreenWidth(activity);109         int height = getScreenHeight(activity);110         Bitmap bp = null;111         bp = Bitmap.createBitmap(bmp, 0, statusBarHeight, width, height112                 - statusBarHeight);113         view.destroyDrawingCache();114         return bp;115     }116 }

代码引用

1 package com.sun.mytext; 2  3 import android.app.Activity; 4 import android.support.v7.app.AppCompatActivity; 5 import android.os.Bundle; 6 /** 7  * @author Sigal 8  * on 2018/12/18 9  * note:10  */11 public class MainActivity extends Activity {12 13     @Override14     protected void onCreate(Bundle savedInstanceState) {15         super.onCreate(savedInstanceState);16         setContentView(R.layout.activity_main);17         // 设置TextView可展示的宽度 ( 父控件宽度 - 左右margin - 左右padding）18         int whidth = ScreenUtils.getScreenWidth(this) - PxUtils.dp2px(this, 16 * 2);19         ExpandTextView mContentExpandTextView = findViewById(R.id.etv);20         mContentExpandTextView.initWidth(whidth);21         // 设置最大行数(如果SDK >= 16 也可以直接在xml里设置)22         mContentExpandTextView.setMaxLines(3);23         String content = "披绣闼，俯雕甍，山原旷其盈视，川泽纡其骇瞩。闾阎扑地，钟鸣鼎食之家；" +24                 "舸舰弥津，青雀黄龙之舳。云销雨霁，彩彻区明。落霞与孤鹜齐飞，秋水共长天一色。渔舟唱晚，响穷彭蠡之滨；雁阵惊寒，声断衡阳之浦。\n" +25                 "\n" +26                 "遥襟甫畅，逸兴遄飞。爽籁发而清风生，纤歌凝而白云遏。睢园绿竹，气凌彭泽之樽；" +27                 "邺水朱华，光照临川之笔。四美具，二难并。穷睇眄于中天，极娱游于暇日。天高地迥，" +28                 "觉宇宙之无穷；兴尽悲来，识盈虚之有数。望长安于日下，目吴会于云间。地势极而南溟深，天柱高而北辰远。关山难越，" +29                 "谁悲失路之人？萍水相逢，尽是他乡之客。怀帝阍而不见，奉宣室以何年？\n" +30                 "\n" +31                 "嗟乎！时运不齐，命途多舛。冯唐易老，李广难封。屈贾谊于长沙，非无圣主；窜梁鸿于海曲，岂乏明时？所赖君子见机，达人知命。" +32                 "老当益壮，宁移白首之心？穷且益坚，不坠青云之志。酌贪泉而觉爽，处涸辙以犹欢。北海虽赊，扶摇可接；东隅已逝，桑榆非晚。" +33                 "孟尝高洁，空余报国之情；阮籍猖狂，岂效穷途之哭！";34         mContentExpandTextView.setCloseText(content);35     }36 }

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转载于:https://www.cnblogs.com/sj-anhui/p/10139376.html

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