自定义带闪动和多背景的textview

来源：互联网发布：山西大学软件学院编辑：程序博客网时间：2024/06/06 10:48

1 首先自定义一个多背景的textview

import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.util.AttributeSet;import android.widget.TextView;/** * 作者：水东流 * 时间：2016/4/20 * 带框文字效果textview */public class MyTextView extends TextView {    private Paint mpaint1;//画笔1    private Paint mpaint2;//画笔2    public MyTextView(Context context) {        this(context, null);    }    public MyTextView(Context context, AttributeSet attrs) {        super(context, attrs);        init();    }    public MyTextView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        init();    }    private void init() {        mpaint1 = new Paint();        mpaint2 = new Paint();        mpaint1.setColor(getResources().getColor(android.R.color.holo_blue_light));        mpaint2.setColor(Color.WHITE);//背景色        mpaint1.setStyle(Paint.Style.FILL);        mpaint2.setStyle(Paint.Style.FILL);    }    /**     * 绘图     *     * @param canvas     */    @Override    protected void onDraw(Canvas canvas) {        //绘制外层矩形        canvas.drawRect(0, 0, getMeasuredWidth(), getMeasuredHeight(), mpaint1);        //绘制内侧矩形        canvas.drawRect(10, 10, getMeasuredWidth() - 10, getMeasuredHeight() - 10, mpaint2);        canvas.save();        //绘制文字前平移10像素        canvas.translate(10, 0);        //父类的方法，绘制文本        super.onDraw(canvas);        canvas.restore();    }

一般拓展是在onDraw方法中对原生控件行为进行拓展

2 下面是带闪动的多背景textview，这里就直接继承上面的多背景textview了

import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.LinearGradient;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.Shader;import android.util.AttributeSet;/** * 作者：水东流 * 时间：2016/4/20 * 闪动效果 */public class MyMoveView extends  MyTextView {    private int mViewWidth = 0;//宽度    private Paint mpaint;    private LinearGradient mLinearGradient;    private Matrix mGradientMatrix;    private  int mTanslate;    public MyMoveView(Context context) {        super(context);    }    public MyMoveView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public MyMoveView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);    }    /**     * 在此初始化闪动所需值     * @param w     * @param h     * @param oldw     * @param oldh     */    @Override    protected void onSizeChanged(int w, int h, int oldw, int oldh) {        super.onSizeChanged(w, h, oldw, oldh);        if (mViewWidth == 0) {            mViewWidth = getMeasuredWidth();            if (mViewWidth > 0) {                mpaint = getPaint();                mLinearGradient=new LinearGradient(0,0,mViewWidth,0,new int[]{Color.BLUE,0xfffffff,Color.BLUE},null, Shader.TileMode.CLAMP);                mpaint.setShader(mLinearGradient);                mGradientMatrix=new Matrix();            }        }    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        if(mGradientMatrix!=null){            mTanslate+=mViewWidth;            if(mTanslate>2*mViewWidth){                mTanslate=-mViewWidth;            }            mGradientMatrix.setTranslate(mTanslate,0);            mLinearGradient.setLocalMatrix(mGradientMatrix);            postInvalidateDelayed(100);        }    }}

这里在onDraw方法里面，通过矩阵的方式来不断平移渐变效果，从而在绘制文字时，产生动态的闪动效果

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