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[操作系统]android textview 自动换行 整齐排版


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)......

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

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/goagent/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:

 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     @Override17     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 }

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: 

 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   }

3.3  话不多说,效果如下:

  [转载请保留本文地址:http://www.cnblogs.com/goagent/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 import android.content.Context; 2 import android.graphics.Paint; 3 import android.text.TextUtils; 4 import android.util.AttributeSet; 5 import android.widget.TextView; 6  7 public class AutoSplitTextView extends TextView { 8   private boolean mEnabled = true; 9 10   public AutoSplitTextView(Context context) {11     super(context);12   }13 14   public AutoSplitTextView(Context context, AttributeSet attrs) {15     super(context, attrs);16   }17 18   public AutoSplitTextView(Context context, AttributeSet attrs, int defStyle) {19     super(context, attrs, defStyle);20   }21   22   public void setAutoSplitEnabled(boolean enabled) {23     mEnabled = enabled;24   }25   26   @Override27   protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {28     if (MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY 29       && MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.EXACTLY30       && getWidth() > 0 31       && getHeight() > 032       && mEnabled) {33       String newText = autoSplitText(this);34       if (!TextUtils.isEmpty(newText)) {35         setText(newText);36       }37     }38     super.onMeasure(widthMeasureSpec, heightMeasureSpec);39   }40   41   private String autoSplitText(final TextView tv) {42     final String rawText = tv.getText().toString(); //原始文本43     final Paint tvPaint = tv.getPaint(); //paint,包含字体等信息44     final float tvWidth = tv.getWidth() - tv.getPaddingLeft() - tv.getPaddingRight(); //控件可用宽度45     46     //将原始文本按行拆分47     String [] rawTextLines = rawText.replaceAll("\r", "").split("\n");48     StringBuilder sbNewText = new StringBuilder();49     for (String rawTextLine : rawTextLines) {50       if (tvPaint.measureText(rawTextLine) <= tvWidth) {51         //如果整行宽度在控件可用宽度之内,就不处理了52         sbNewText.append(rawTextLine);53       } else {54         //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55         float lineWidth = 0;56         for (int cnt = 0; cnt != rawTextLine.length(); ++cnt) {57           char ch = rawTextLine.charAt(cnt);58           lineWidth += tvPaint.measureText(String.valueOf(ch));59           if (lineWidth <= tvWidth) {60             sbNewText.append(ch);61           } else {62             sbNewText.append("\n");63             lineWidth = 0;64             --cnt;65           }66         }67       }68       sbNewText.append("\n");69     }70     71     //把结尾多余的\n去掉72     if (!rawText.endsWith("\n")) {73       sbNewText.deleteCharAt(sbNewText.length() - 1);74     }75     76     return sbNewText.toString();77   }78 }

View Code

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/goagent/p/5159125.html]