android Edittext内容字体大小动态变化

转自:edittext内容随字体大小动态变化,具体代码如下:

package com.yitong.mbank.android.views;

import android.content.Context;
import android.graphics.Paint;
import android.graphics.Paint.FontMetrics;
import android.util.AttributeSet;
import android.widget.EditText;

public class AutoAdjustSizeEditText extends EditText {
	private static float DEFAULT_MIN_TEXT_SIZE = 10; // 最小的字体大小
	private static float DEFAULT_MAX_TEXT_SIZE = 20;// 验证大部分手机情况下无效值

	// Attributes
	private Paint testPaint;
	private float minTextSize, maxTextSize;

	public AutoAdjustSizeEditText(Context context, AttributeSet attrs) {
		super(context, attrs);
		initialise();
	}

	private void initialise() {
		testPaint = new Paint();
		testPaint.set(this.getPaint()); // 获取模拟的paint

		// max size defaults to the intially specified text size unless it is
		// too small
		maxTextSize = this.getTextSize();// 获取单个字体的像素
		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();// 获取改TextView的画布可用大小        
			float trySize = maxTextSize;
			float scaled = getContext().getResources().getDisplayMetrics().scaledDensity;
			testPaint.setTextSize(trySize * scaled);// 模拟注意乘以scaled
			while ((trySize > minTextSize)
					&& (testPaint.measureText(text) > availableWidth)) {
				trySize -= 2;
				FontMetrics fm = testPaint.getFontMetrics();
				float scaled1 = (float) (this.getHeight() / (Math
						.ceil(fm.descent - fm.top) + 2));
				float scaled2 = (float) ((testPaint.measureText(text) / availableWidth));
				if (scaled1 >= 1.75 & scaled1 >= scaled2) {// 注意1.75是三星s4 小米3
															// 的适合数值（当然包括我的联想了)
					break;
				}
				if (trySize <= minTextSize) {
					trySize = minTextSize;
					break;
				}
				testPaint.setTextSize(trySize * scaled);
			}
			this.setTextSize(trySize);// 等同于this.getPaint().set(trySize*scaled);
		}
	};

	@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);
		}
	}
}

然后直接在你的xml布局文件中这样使用: