Android编程实现自动调整TextView字体大小以适应文字长度的方法

本文实例讲述了android编程实现自动调整textview字体大小以适应文字长度的方法。分享给大家供大家参考，具体如下：

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);
    }
  }
}

希望本文所述对大家android程序设计有所帮助。