自定义View之自定义文字闪动效果

自定义View之自定义文字闪动效果，代码是学习《Android群英会》中的例子略有改动

效果如图

直接上自定义控件的代码

package com.cheng.cc.customcontrols.views;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;import android.widget.TextView;/** * @author Created by cc on 17/6/2. * @fileName LightningTextView * @githublink https://github.com/cc0819 * @csdnlink http://blog.csdn.net/qq_25404567 */public class LightningTextView extends TextView {    private int mViewWidth;    private int mTranslate;    private Paint mPaint;    private LinearGradient mLinearGradient;    private Matrix mGradientMatrix;    public LightningTextView(Context context) {        super(context);    }    public LightningTextView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public LightningTextView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);    }    @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,Color.YELLOW,Color.RED},                        null, Shader.TileMode.CLAMP);//设置线性渲染的颜色                // CLAMP表示重复最后一种颜色直到该View结束的地方                // REPEAT表示着色器在水平或者垂直方向上对控件进行重复着色                // MIRROR模式会在水平方向或者垂直方向上以镜像的方式进行渲染                mPaint.setShader(mLinearGradient);                mGradientMatrix = new Matrix();            }        }    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        if (mGradientMatrix != null){            mTranslate += mViewWidth / 5 ;//已控件宽度的五分之一移动渲染的矩阵达到闪动效果            if (mTranslate > 2*mViewWidth){                mTranslate = -mViewWidth;            }            mGradientMatrix.setTranslate(mTranslate,0);            mLinearGradient.setLocalMatrix(mGradientMatrix);            postInvalidateDelayed(80);        }    }}

布局中引用

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    android:gravity="center"    tools:context="com.cheng.cc.customcontrols.activity.TextLightning_Activity">    <com.cheng.cc.customcontrols.views.LightningTextView        android:id="@+id/lightning"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:gravity="center"/></LinearLayout>

文字内容和大小是在代码中动态设置的

lightning.setText("LIGHTNING TEXTVIEW");lightning.setTextSize(50);

github下载地址：https://github.com/cc0819/CustomControls