Android 自定义 TextView 实现高度和宽度，解决字体适配问题

import android.content.Context;import android.graphics.Paint;import android.support.annotation.Nullable;import android.text.TextPaint;import android.util.AttributeSet;import android.view.Gravity;import android.widget.TextView;/**  * Created by akitaka on 2018-07-05. * https://zhima.blog.csdn.net/  * https://juejin.cn/user/4265760844943479/columns  * https://www.zhihu.com/people/zhimalier  * @filename FitHeightTextView  * @describe 根据高度自适应字体文字大小  * @email 960576866@qq.com */public class FitHeightTextView extends TextView {    private Paint mTextPaint;    private float mMaxTextSize; // 获取当前所设置文字大小作为最大文字大小    private float mMinTextSize = 8;    //最小的字体大小     public FitHeightTextView(Context context) {        super(context);    }     public FitHeightTextView(Context context, @Nullable AttributeSet attrs) {        super(context, attrs);        setGravity(getGravity() | Gravity.CENTER_VERTICAL); // 默认水平居中        setLines(1);        initialise();    }     private void initialise() {        mTextPaint = new TextPaint();        mTextPaint.set(this.getPaint());        //默认的大小是设置的大小，如果撑不下了 就改变        mMaxTextSize = this.getTextSize();    }     //文字改变的时候    @Override    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {        refitText(text.toString(), this.getHeight());   //textview视图的高度        super.onTextChanged(text, start, lengthBefore, lengthAfter);    }     private void refitText(String textString, int height) {        if (height > 0) {            //减去边距为字体的实际高度            int availableHeight = height - this.getPaddingTop() - this.getPaddingBottom();               float trySize = mMaxTextSize;            mTextPaint.setTextSize(trySize);            while (mTextPaint.descent()-mTextPaint.ascent() > availableHeight) {                  //测量的字体高度过大，不断地缩放                trySize -= 1;  //字体不断地减小来适应                if (trySize <= mMinTextSize) {                    trySize = mMinTextSize;  //最小为这个                    break;                }                mTextPaint.setTextSize(trySize);            }            setTextSize(px2sp(getContext(), trySize));        }    }     //大小改变的时候    @Override    protected void onSizeChanged(int w, int h, int oldw, int oldh) {        if (h != oldh) {            refitText(this.getText().toString(), h);        }    }     /**     * 将px值转换为sp值，保证文字大小不变     */    public static float px2sp(Context context, float pxValue) {        float fontScale = context.getResources().getDisplayMetrics().scaledDensity;        return (pxValue / fontScale);    }}

 android:textSize  保持为支持最大设备的字体大小

  <cn.jucheng.www.cpr.util.FitHeightTextView                            android:layout_width="wrap_content"                            android:layout_height="wrap_content"                            android:gravity="center_vertical"                            android:text="设置"                            android:textSize="28sp"                            android:textColor="#56BBe0" />

/**  * Created by akitaka on 2018-07-05. * https://zhima.blog.csdn.net/  * https://juejin.cn/user/4265760844943479/columns  * https://www.zhihu.com/people/zhimalier  * @filename FitHeightTextView  * @describe 根据高度自适应字体文字大小  * @email 960576866@qq.com */public class FitTextView extends TextView{	 private Paint mTextPaint;	    private float mMaxTextSize; // 获取当前所设置文字大小作为最大文字大小	    private float mMinTextSize = 3; 	    public FitTextView(Context context) {	        this(context, null);	    } 	    public FitTextView(Context context, AttributeSet attrs) {	        super(context, attrs);	        setGravity(getGravity() | Gravity.CENTER_VERTICAL); // 默认水平居中	        setLines(1);	        initialise();	    } 	    @Override	    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {	        refitText(text.toString(), this.getWidth());	        super.onTextChanged(text, start, lengthBefore, lengthAfter);	    } 	    private void initialise() {	        mTextPaint = new TextPaint();	        mTextPaint.set(this.getPaint());	        // 最大的大小默认为特定的文本大小，除非它太小了	        mMaxTextSize = this.getTextSize();//	        mMinTextSize = 8;	    } 	    @Override	    protected void onSizeChanged(int w, int h, int oldw, int oldh) {	        if (w != oldw) {	            refitText(this.getText().toString(), w);	        }	    } 	    /**	     * Resize 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 = mMaxTextSize; 	            mTextPaint.setTextSize(trySize);	            while (mTextPaint.measureText(text) > availableWidth) { 	                trySize -= 1;	                if (trySize <= mMinTextSize) {	                    trySize = mMinTextSize;	                    break;	                }	                mTextPaint.setTextSize(trySize);	            } 	            // setTextSize参数值为sp值	            setTextSize(px2sp(getContext(), trySize));	        }	    } 	    /**	     * 将px值转换为sp值，保证文字大小不变	     */	    public static float px2sp(Context context, float pxValue) {	        float fontScale = context.getResources().getDisplayMetrics().scaledDensity;	        return (pxValue / fontScale);	    } }