Android 如何实现竖排文字显示？

转自：http://blog.csdn.net/liaoyp_ios_android/article/details/6949768

 在android.graphics.Canvas类中有个沿路径画字的方法
 void drawTextOnPath(String text, Path path, float hOffset, float vOffset, Paint paint)
 Draw the text, with origin at (x,y), using the specified paint, along the specified path.
 void drawTextOnPath(char[] text, int index, int count, Path path, float hOffset, float vOffset, Paint paint)
 Draw the text, with origin at (x,y), using the specified paint, along the specified path.


 Test.java代码://需要在layout中定义Test，且设置背景,在java代码中设置test Text

 public class Test extends View {

      private Paint paint;
      private Path path;
      private Matrix matrix;
      private int width = -1;
      private int height = -1;
      private float left = 3;
      private float top = 18;
      private String title = "";
      BitmapDrawable drawable = (BitmapDrawable) getBackground();

      public Test(Context context, AttributeSet attrs) {
          super(context, attrs);
          paint = new Paint();
          paint.setColor(Color.WHITE);//定义字体颜色
          paint.setTextSize(14);//定义字体大小
          path = new Path();
          path.lineTo(0,500);//定义字符路径
          matrix = new Matrix();
          Log.v("onMeasure", "2");
      }

      @Override
      protected void onDraw(Canvas canvas) {
          //画背景
          Bitmap b = Bitmap.createBitmap(drawable.getBitmap(),0,0,width,height);
          canvas.drawBitmap(b, matrix, paint);
          //画字
          showText(canvas, title);
      }


      private void showText(Canvas canvas, String text){
          float w;
          final int len = text.length();
          float py = 0 + top;
          for(int i=0; i<len; i ++){
              char c = text.charAt(i);
               w = paint.measureText(text, i, i+1);//获取字符宽度
               StringBuffer b = new StringBuffer();
               b.append(c);
               if(py > 81){//定义字的范围
              return;
              }
              if(isChinese(c)){
                  py += w;
                  if(py > 81){
                      return;
                  }
                  canvas.drawText(b.toString(), left, py, paint); //中文处理方法
               }else {
                  canvas.drawTextOnPath(b.toString(), path, py, -left-2, paint);//其他文字处理方法
                  py += w;
              }
          }
      }

      public void setText(String title){
          this.title = title;
      }

      public String getText(){
          return title;
      }


      private boolean isChinese(char c) {
          Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);
          if (ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS
               || ub == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS
              || ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A
              || ub == Character.UnicodeBlock.GENERAL_PUNCTUATION
              || ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION
              || ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS) {
              return true;
          }
          return false;
      }

      //重写View大小方法，使view大小为背景图片大小
      @Override
      protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
          // super.onMeasure(widthMeasureSpec, heightMeasureSpec);
          if (null != getBackground()) {

              int h = drawable.getIntrinsicHeight();
              int w = drawable.getIntrinsicWidth();
              Log.v("onMeasure", "null != getBackground() h:" + h + " w:" + w);
              width = w;
              height = h;
              setMeasuredDimension(w, h);
          } else {
              width = widthMeasureSpec;
              height = heightMeasureSpec;
              super.measure(widthMeasureSpec, heightMeasureSpec);
          }
     }

 }




 在Android中，若要通过程序改变屏幕显示的方向，必须要覆盖setRequestedOrientation()方法，而若要取得目前的屏幕方向，则需要访问getRequestedOrientation()方法。本范例为求简要示范更改做法，设计了一个按钮，当单击按钮的同时，判断当下的屏幕方向，例如竖排（PORTRAIT），则将其更改为横排（LANDSCAPE）；若为横排（LANDSCAPE），则将其更改为竖排（PORTRAIT）