Android编程实现自动调整TextView字体大小以适应文字长度的方法

package com.test.android.textview;import android.content.Context;import android.graphics.Paint;import android.util.AttributeSet;import android.widget.TextView;public class CustomTextView extends TextView {  private static float DEFAULT_MIN_TEXT_SIZE = 10;  private static float DEFAULT_MAX_TEXT_SIZE = 20;  // Attributes  private Paint testPaint;  private float minTextSize;  private float maxTextSize;  public CustomTextView(Context context, AttributeSet attrs) {    super(context, attrs);    initialise();  }  private void initialise() {    testPaint = new Paint();    testPaint.set(this.getPaint());    // max size defaults to the intially specified text size unless it is    // too small    maxTextSize = this.getTextSize();    if (maxTextSize <= DEFAULT_MIN_TEXT_SIZE) {      maxTextSize = DEFAULT_MAX_TEXT_SIZE;    }    minTextSize = DEFAULT_MIN_TEXT_SIZE;  }  /**  * Re size the font so the specified text fits in the text box * assuming  * the text box is the specified width.  */  private void refitText(String text, int textWidth) {    if (textWidth > 0) {      int availableWidth = textWidth - this.getPaddingLeft() -        this.getPaddingRight();      float trySize = maxTextSize;      testPaint.setTextSize(trySize);      while ((trySize > minTextSize) &&          (testPaint.measureText(text) > availableWidth)) {        trySize -= 1;        if (trySize <= minTextSize) {          trySize = minTextSize;          break;        }        testPaint.setTextSize(trySize);      }      this.setTextSize(trySize);    }  }  @Override  protected void onTextChanged(CharSequence text, int start, int before,    int after) {    super.onTextChanged(text, start, before, after);    refitText(text.toString(), this.getWidth());  }  @Override  protected void onSizeChanged(int w, int h, int oldw, int oldh) {    if (w != oldw) {      refitText(this.getText().toString(), w);    }  }}