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android tv 实现颜色条滚动效果

直接贴代码:

ColorView.java

package com.xxx.demo;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.WindowManager;
/**
 * 色彩效果view1
 */
public class ColorView extends View {
    int width;
    int height;
    Paint p;
    int i = 0;
    int all = 256 * 5;//颜色值变化
    int exteraLength = 1;
    Context context = null;
    int j = 0;
    int mLength = 0;//每次重绘时j的增量值

    public ColorView(Context context) {
        super(context);
        this.context = context;
        WindowManager wm = (WindowManager) getContext().getSystemService(
                Context.WINDOW_SERVICE);
        width = wm.getDefaultDisplay().getWidth();
        height = wm.getDefaultDisplay().getHeight();
        //判断是否是标准的高度
        System.out.println("width==" + width);
        System.out.println("height==" + height);
        p = new Paint();
        if (all >= width) {
            mLength = 80;
        } else {
            mLength = 30;
            exteraLength = (int) Math.ceil(1.0 * all / (width - all));
        }
        this.setFocusable(true);
        this.setKeepScreenOn(true);
        i = 0;
    }
    public ColorView(Context context, AttributeSet attributeSet) {
        super(context, attributeSet);
        this.context = context;
        WindowManager wm = (WindowManager) getContext().getSystemService(
                Context.WINDOW_SERVICE);
        width = wm.getDefaultDisplay().getWidth();
        height = wm.getDefaultDisplay().getHeight();
        System.out.println("width==" + width);
        System.out.println("height==" + height);
        p = new Paint();
        p.setAntiAlias(true);
        p.setStyle(Paint.Style.FILL);
        if (all >= width) {
            mLength = 80;
        } else {
            mLength = 30;
            exteraLength = (int) Math.ceil(1.0 * all / (width - all));
        }
        this.setFocusable(true);
        this.setKeepScreenOn(true);
        i = 0;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (j > all) {
            //结束的情况。还是需要绘制的,不然界面会变黑
            myDraw(canvas);
            System.out.println("end");
            return;
        }
        myDraw(canvas);
        j+=mLength;//改变j的值
        invalidate();//onDraw后,重新绘制view,主观上产生动画效果
    }


    public void myDraw(Canvas canvas) {
// 创建画笔
//		红(R:255 G:0 B:0)
//		橙(R:255 G:156 B:0)
//		黄(R:255 G:255 B:0)
//		绿(R:0 G:255 B:0)
//		青(R: G:255 B:255)
//		蓝(R:0 G:0 B:255)
//		紫(R:255 G: B:255)
        System.out.println("canvas");
        Log.i("Canvas:X:", "complexdraw");
        i = 0;
        while (i <= j) {
            if (i <= 255) {
                p.setColor(Color.rgb(255, i, 0));
            } else if (i >= 256 && i <= 511) {
                p.setColor(Color.rgb(511 - i, 255, 0));
            } else if (i >= 512 && i <= 767) {
                p.setColor(Color.rgb(0, 255, i - 512));
            } else if (i >= 768 && i <= 1023) {
                p.setColor(Color.rgb(0, 1023 - i, 255));
            } else if (i >= 1024 && i <= 1279) {
                p.setColor(Color.rgb(i - 1024, 0, 255));
            }
            //处理不同的分辨率,造成画图的差异性,均分颜色值,屏幕宽度1280,颜色值的范围也是1280刚刚好,如果是小米电视的,屏幕宽度为1920,多出来的,需要均分,下面便是处理方式
            if (exteraLength != 1) {
                if (i % exteraLength == exteraLength - 1) {
                    System.out.println("exteraLength==" + exteraLength);
                    System.out.println("current==" + i);
                    canvas.drawLine(i + i / exteraLength, 0, i + i / exteraLength, height, p);//画线
                    canvas.drawLine(i + i / exteraLength + 1, 0, i + i / exteraLength + 1, height, p);
                } else {
                    System.out.println("exteraLength==1--------->" + exteraLength);
                    System.out.println("current==" + i);
                    canvas.drawLine(i + i / exteraLength, 0, i + i / exteraLength, height, p);
                }
            } else {
                canvas.drawLine(i, 0, i, height, p);
            }
            i++;
        }
    }
}

MainActivity.java

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_color);
    }
}

activity_color.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent">
    <com.xxx.demo.ColorView
            android:id="@+id/colorView"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            />
</LinearLayout>

在自定义view中的onDraw()方法中,调用invalidate()方法,可以实现类似于小球移动的效果。。