一、问题在哪里?

textview显示长文字时会进行自动折行,如果遇到一些特殊情况,自动折行会杯具成这个样子:

上述特殊情况包括:

1)全角/半角符号混排(一般是数字、字母、汉字混排)

2)全角/半角标点符号出现在行首时,该标点符号会连同其前一个字符跳到下一行

3)英文单词不能被折成两行

4)......

 

二、怎么搞?

通常有两类解决方案:

1)修改文本内容,将所有符号全角化、在标点符号前面加空格等等……

2)保持文本内容不变,在合适的位置将文本手动分成多行

本文采用第二种方案,更加通用,也最大限度的保留了原文本。

 [转载请保留本文地址:http://www.cnblogs.com/snser/p/5159125.html]

三、开始干活

3.1  “在合适的位置将文本手动分成多行”需要知道textview的实际宽度、字体大小等信息,框架如下:

复制代码
 1 public class TestCActivity extends Activity {
 2     private TextView mText;
 3     
 4     @Override
 5     protected void onCreate(Bundle savedInstanceState) {
 6         super.onCreate(savedInstanceState);
 7         
 8         setContentView(R.layout.testc);
 9         
10         mText = (TextView)findViewById(R.id.txt);
11         mText.setText("本文地址http://www.cnblogs.com/goagent/p/5159125.html本文地址啊本文。地址。啊http://www.cnblogs.com/goagent/p/5159125.html");
12         mText.getViewTreeObserver().addOnGlobalLayoutListener(new OnTvGlobalLayoutListener());
13     }
14 
15     private class OnTvGlobalLayoutListener implements OnGlobalLayoutListener {
16         @Override
17         public void onGlobalLayout() {
18             mText.getViewTreeObserver().removeOnGlobalLayoutListener(this);
19             final String newText = autoSplitText(mText);
20             if (!TextUtils.isEmpty(newText)) {
21                 mText.setText(newText);
22             }
23         }
24     }
25     
26     private String autoSplitText(final TextView tv) {
27         final String rawText = tv.getText().toString();
28         final Paint tvPaint = tv.getPaint();
29         final int tvWidth = tv.getWidth() - tv.getPaddingLeft() - tv.getPaddingRight();
30         
31         //autoSplitText begin....
32         String newText = rawText;
33         //autoSplitText end....
34         
35         return newText;
36     }
37 }
复制代码

3.2  实现自动分割文本,简单来说就是用textview的paint逐字符测量,如果发现当前行绘制不下了,就手动加入一个换行符: 

复制代码
 1     private String autoSplitText(final TextView tv) {
 2         final String rawText = tv.getText().toString(); //原始文本
 3         final Paint tvPaint = tv.getPaint(); //paint,包含字体等信息
 4         final float tvWidth = tv.getWidth() - tv.getPaddingLeft() - tv.getPaddingRight(); //控件可用宽度
 5         
 6         //将原始文本按行拆分
 7         String [] rawTextLines = rawText.replaceAll("\r", "").split("\n");
 8         StringBuilder sbNewText = new StringBuilder();
 9         for (String rawTextLine : rawTextLines) {
10             if (tvPaint.measureText(rawTextLine) <= tvWidth) {
11                 //如果整行宽度在控件可用宽度之内,就不处理了
12                 sbNewText.append(rawTextLine);
13             } else {
14                 //如果整行宽度超过控件可用宽度,则按字符测量,在超过可用宽度的前一个字符处手动换行
15                 float lineWidth = 0;
16                 for (int cnt = 0; cnt != rawTextLine.length(); ++cnt) {
17                     char ch = rawTextLine.charAt(cnt);
18                     lineWidth += tvPaint.measureText(String.valueOf(ch));
19                     if (lineWidth <= tvWidth) {
20                         sbNewText.append(ch);
21                     } else {
22                         sbNewText.append("\n");
23                         lineWidth = 0;
24                         --cnt;
25                     }
26                 }
27             }
28             sbNewText.append("\n");
29         }
30         
31         //把结尾多余的\n去掉
32         if (!rawText.endsWith("\n")) {
33             sbNewText.deleteCharAt(sbNewText.length() - 1);
34         }
35         
36         return sbNewText.toString();
37     }
复制代码

3.3  话不多说,效果如下:

 [转载请保留本文地址:http://www.cnblogs.com/snser/p/5159125.html]

四、更多玩法

4.1  可以封装一个自定义的textview,直接包含自动排版换行的功能:

 1 package cc.snser.test;
 2 
 3 import android.content.Context;
 4 import android.graphics.Paint;
 5 import android.text.TextUtils;
 6 import android.util.AttributeSet;
 7 import android.widget.TextView;
 8 
 9 public class AutoSplitTextView extends TextView {
10     private boolean mEnabled = true;
11 
12     public AutoSplitTextView(Context context) {
13         super(context);
14     }
15 
16     public AutoSplitTextView(Context context, AttributeSet attrs) {
17         super(context, attrs);
18     }
19 
20     public AutoSplitTextView(Context context, AttributeSet attrs, int defStyle) {
21         super(context, attrs, defStyle);
22     }
23     
24     public void setAutoSplitEnabled(boolean enabled) {
25         mEnabled = enabled;
26     }
27     
28     @Override
29     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
30         if (MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY 
31             && MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.EXACTLY
32             && getWidth() > 0 
33             && getHeight() > 0
34             && mEnabled) {
35             String newText = autoSplitText(this);
36             if (!TextUtils.isEmpty(newText)) {
37                 setText(newText);
38             }
39         }
40         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
41     }
42     
43     private String autoSplitText(final TextView tv) {
44         final String rawText = tv.getText().toString(); //原始文本
45         final Paint tvPaint = tv.getPaint(); //paint,包含字体等信息
46         final float tvWidth = tv.getWidth() - tv.getPaddingLeft() - tv.getPaddingRight(); //控件可用宽度
47         
48         //将原始文本按行拆分
49         String [] rawTextLines = rawText.replaceAll("\r", "").split("\n");
50         StringBuilder sbNewText = new StringBuilder();
51         for (String rawTextLine : rawTextLines) {
52             if (tvPaint.measureText(rawTextLine) <= tvWidth) {
53                 //如果整行宽度在控件可用宽度之内,就不处理了
54                 sbNewText.append(rawTextLine);
55             } else {
56                 //如果整行宽度超过控件可用宽度,则按字符测量,在超过可用宽度的前一个字符处手动换行
57                 float lineWidth = 0;
58                 for (int cnt = 0; cnt != rawTextLine.length(); ++cnt) {
59                     char ch = rawTextLine.charAt(cnt);
60                     lineWidth += tvPaint.measureText(String.valueOf(ch));
61                     if (lineWidth <= tvWidth) {
62                         sbNewText.append(ch);
63                     } else {
64                         sbNewText.append("\n");
65                         lineWidth = 0;
66                         --cnt;
67                     }
68                 }
69             }
70             sbNewText.append("\n");
71         }
72         
73         //把结尾多余的\n去掉
74         if (!rawText.endsWith("\n")) {
75             sbNewText.deleteCharAt(sbNewText.length() - 1);
76         }
77         
78         return sbNewText.toString();
79     }
80 }
View AutoSplitTextView.java
 1 package cc.snser.test;
 2 
 3 import android.app.Activity;
 4 import android.os.Bundle;
 5 
 6 public class TestCActivity extends Activity {
 7     private AutoSplitTextView mText;
 8     
 9     @Override
10     protected void onCreate(Bundle savedInstanceState) {
11         super.onCreate(savedInstanceState);
12         
13         setContentView(R.layout.testc);
14         
15         mText = (AutoSplitTextView)findViewById(R.id.txt);
16         mText.setText("本文地址http://www.cnblogs.com/goagent/p/5159125.html本文地址啊本文。地址。啊http://www.cnblogs.com/goagent/p/5159125.html");
17     }
18 }
View TestCActivity.java
 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:background="@android:color/white"
 6     android:orientation="vertical" >
 7 
 8     <cc.snser.test.AutoSplitTextView
 9         android:id="@+id/txt"
10         android:layout_width="match_parent"
11         android:layout_height="200dp"
12         android:layout_marginTop="11dp"
13         android:layout_marginLeft="11dp"
14         android:layout_marginRight="11dp"
15         android:background="@android:color/holo_blue_light"
16         android:textSize="20sp"
17         android:textColor="@android:color/black" />
18     
19 </LinearLayout>
View testc.xml

4.2  实现悬挂缩进 

 1     private String autoSplitText(final TextView tv, final String indent) {
 2         final String rawText = tv.getText().toString(); //原始文本
 3         final Paint tvPaint = tv.getPaint(); //paint,包含字体等信息
 4         final float tvWidth = tv.getWidth() - tv.getPaddingLeft() - tv.getPaddingRight(); //控件可用宽度
 5         
 6         //将缩进处理成空格
 7         String indentSpace = "";
 8         float indentWidth = 0;
 9         if (!TextUtils.isEmpty(indent)) {
10             float rawIndentWidth = tvPaint.measureText(indent);
11             if (rawIndentWidth < tvWidth) {
12                 while ((indentWidth = tvPaint.measureText(indentSpace)) < rawIndentWidth) {
13                     indentSpace += " ";
14                 }
15             }
16         }
17         
18         //将原始文本按行拆分
19         String [] rawTextLines = rawText.replaceAll("\r", "").split("\n");
20         StringBuilder sbNewText = new StringBuilder();
21         for (String rawTextLine : rawTextLines) {
22             if (tvPaint.measureText(rawTextLine) <= tvWidth) {
23                 //如果整行宽度在控件可用宽度之内,就不处理了
24                 sbNewText.append(rawTextLine);
25             } else {
26                 //如果整行宽度超过控件可用宽度,则按字符测量,在超过可用宽度的前一个字符处手动换行
27                 float lineWidth = 0;
28                 for (int cnt = 0; cnt != rawTextLine.length(); ++cnt) {
29                     char ch = rawTextLine.charAt(cnt);
30                     //从手动换行的第二行开始,加上悬挂缩进
31                     if (lineWidth < 0.1f && cnt != 0) {
32                         sbNewText.append(indentSpace);
33                         lineWidth += indentWidth;
34                     }
35                     lineWidth += tvPaint.measureText(String.valueOf(ch));
36                     if (lineWidth <= tvWidth) {
37                         sbNewText.append(ch);
38                     } else {
39                         sbNewText.append("\n");
40                         lineWidth = 0;
41                         --cnt;
42                     }
43                 }
44             }
45             sbNewText.append("\n");
46         }
47         
48         //把结尾多余的\n去掉
49         if (!rawText.endsWith("\n")) {
50             sbNewText.deleteCharAt(sbNewText.length() - 1);
51         }
52         
53         return sbNewText.toString();
54     }
View Code

调用方式:

 autoSplitText(tv, "1、"); 

悬挂缩进效果:

 [转载请保留本文地址:http://www.cnblogs.com/snser/p/5159125.html]

点赞(0)

评论列表 共有 0 条评论

暂无评论
立即
投稿
发表
评论
返回
顶部