标签：width border over mcu null style canvas 必须 fill
描边 首先的想法就是俩个textview 这样是不是一下子就理解了 感觉很简单实现了？
1.在res下的values里面的colors.xml 新增一个描边颜色 我用的是白色
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="border_text" >#ffffff</color>
</resources>
2.新增自定义textview
package com.example.myapplication1.widget; import android.content.Context; import android.graphics.Canvas; import android.graphics.Paint.Style; import android.text.TextPaint; import android.util.AttributeSet; import android.view.ViewGroup; import android.widget.TextView; import androidx.appcompat.widget.AppCompatTextView; import com.example.myapplication1.R; /** * @ClassName StrokeTextView * @Description TODO * @Author ZhangXueTao * @Date 2020/9/10 11:10 * @Version 1.0 模板 解救兔子图文版 描边文字 */ public class StrokeTextView extends AppCompatTextView { private TextView borderText = null;///用于描边的TextView public StrokeTextView(Context context) { super(context); borderText = new TextView(context); init(); } public StrokeTextView(Context context, AttributeSet attrs) { super(context, attrs); borderText = new TextView(context,attrs); init(); } public StrokeTextView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); borderText = new TextView(context,attrs,defStyle); init(); } public void init(){ TextPaint tp1 = borderText.getPaint(); tp1.setStrokeWidth(4); //设置描边宽度 tp1.setStyle(Style.STROKE); //对文字只描边 borderText.setTextColor(getResources().getColor(R.color.border_text)); //设置描边颜色 borderText.setGravity(getGravity()); } @Override public void setLayoutParams (ViewGroup.LayoutParams params){ super.setLayoutParams(params); borderText.setLayoutParams(params); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { CharSequence tt = borderText.getText(); //两个TextView上的文字必须一致 if(tt== null || !tt.equals(this.getText())){ borderText.setText(getText()); this.postInvalidate(); } super.onMeasure(widthMeasureSpec, heightMeasureSpec); borderText.measure(widthMeasureSpec, heightMeasureSpec); } protected void onLayout (boolean changed, int left, int top, int right, int bottom){ super.onLayout(changed, left, top, right, bottom); borderText.layout(left, top, right, bottom); } @Override protected void onDraw(Canvas canvas) { borderText.draw(canvas); super.onDraw(canvas); } }
3.使用
<com.example.myapplication1.widget.StrokeTextView android:id="@+id/tv_yaoshi3" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.85" app:layout_constraintHorizontal_bias="0.9" android:gravity="center" android:layout_width="wrap_content" android:layout_height="24dp" android:textSize="16dp" android:textColor="#FF0000" />
当然还有其他的方法 例如采用两个TextView在一个layout中进行实现，但细想了下，如果我在一个TextView中让其以不同的方式进行两次描绘不就能够达到效果了吗？由于网上没有看到和我类似的方法，故发出来和大家分享，由于只需要重写protected void onDraw(Canvas canvas)；方法即可：
private boolean m_bDrawSideLine = false; // 默认不采用描边 /* (non-Javadoc) * @see android.widget.TextView#onDraw(android.graphics.Canvas) */ @Override protected void onDraw(Canvas canvas) { if (m_bDrawSideLine) { // 描外层 //super.setTextColor(Color.BLUE); // 不能直接这么设，如此会导致递归 setTextColorUseReflection(Color.BLUE); m_TextPaint.setStrokeWidth(3); // 描边宽度 m_TextPaint.setStyle(Style.FILL_AND_STROKE); //描边种类 m_TextPaint.setFakeBoldText(true); // 外层text采用粗体 m_TextPaint.setShadowLayer(1, 0, 0, 0); //字体的阴影效果，可以忽略 super.onDraw(canvas); // 描内层，恢复原先的画笔 //super.setTextColor(Color.BLUE); // 不能直接这么设，如此会导致递归 setTextColorUseReflection(Color.RED); m_TextPaint.setStrokeWidth(0); m_TextPaint.setStyle(Style.FILL_AND_STROKE); m_TextPaint.setFakeBoldText(false); m_TextPaint.setShadowLayer(0, 0, 0, 0); } super.onDraw(canvas); } private void setTextColorUseReflection(int color) { Field textColorField; try { textColorField = TextView.class.getDeclaredField("mCurTextColor"); textColorField.setAccessible(true); textColorField.set(color); textColorField.setAccessible(false); } catch (NoSuchFieldException e) { e.printStackTrace(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } m_TextPaint.setColor(color); }
或者
import android.content.Context; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Paint.FontMetrics; import android.util.AttributeSet; import android.widget.TextView; public class StrokeText extends TextView { private float mBigFontBottom; private float mBigFontHeight; private String text; private Paint mPaint; private int strokeSize = 1; public StrokeText(Context context) { super(context); init(); } public StrokeText(Context context, AttributeSet attrs) { super(context, attrs); init(); } public StrokeText(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(); } private void init() { mPaint = new Paint(); mPaint.setAntiAlias(true); mPaint.setTextSize(getTextSize()); mPaint.setColor(getResources().getColor(R.color.font_paint_color)); FontMetrics fm = mPaint.getFontMetrics(); mBigFontBottom = fm.bottom; mBigFontHeight = fm.bottom - fm.top; } @Override protected void onDraw(Canvas canvas) { if (strokeSize > 0 && strokeSize < 4) { float y = getPaddingTop() + mBigFontHeight - mBigFontBottom; canvas.drawText(text, 0, y - strokeSize, mPaint); canvas.drawText(text, 0, y + strokeSize, mPaint); canvas.drawText(text, 0 + strokeSize, y, mPaint); canvas.drawText(text, 0 + strokeSize, y + strokeSize, mPaint); canvas.drawText(text, 0 + strokeSize, y - strokeSize, mPaint); canvas.drawText(text, 0 - strokeSize, y, mPaint); canvas.drawText(text, 0 - strokeSize, y + strokeSize, mPaint); canvas.drawText(text, 0 - strokeSize, y - strokeSize, mPaint); } super.onDraw(canvas); } @Override public void setText(CharSequence text, BufferType type) { super.setText(text, type); this.text = text.toString(); invalidate(); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); if (strokeSize > 0 && strokeSize < 4) { setMeasuredDimension(getMeasuredWidth() + strokeSize, getMeasuredHeight()); } } }
标签：width border over mcu null style canvas 必须 fill
原文地址：https://www.cnblogs.com/zhangxuetao/p/13645314.html
