内存优化（一），安卓编程软件

@Override

public void onAnimationUpdate(ValueAnimator animation) {

if ((int) animation.getAnimatedValue() != currentColor) {

String b[] = new String[color.length];//移动后的数组

for (int c = 0, size = color.length - 1; c < size; c++) {

b[c + 1] = color[c];

}

b[0] = color[color.length - 1];

color = b;

invalidate();

currentColor = (int) animation.getAnimatedValue();

}

});

valueAnimator.start();

}

利用Android Studio内置的Profiler工具查看内存使用情况：

可以看到内存产生抖动，并且随着程序的运行，内存一直在增加，选择一段时间分析内存中的对象：

可以看到内存中的有大量的Path对象和String对象，一般来说是有异常的，分析代码看看是否能避免这种情况。

可以在onDraw方法里进行优化，优化后的代码：

/**

优化后的IOSStyleLoadingView
onDraw方法里不创建Path和Paint对象，不调用Color.parseColor创建String对象

public class IOSStyleLoadingView extends View {

private final Context context;

private double radius;

private double insideRadius;

private float northwestXStart;

private float northwestYStart;

private float northXStart;

private float northYStart;

private float notheastXStart;

private float notheastYStart;

private float eastXStart;

private float eastYStart;

private float southeastXStart;

private float southeastYStart;

private float southXStart;

private float southYStart;

private float southwestXStart;

private float southwestYStart;

private float westXStart;

private float westYStart;

private float northwestXEnd;

private float northwestYEnd;

private float northXEnd;

private float northYEnd;

private float notheastXEnd;

private float notheastYEnd;

private float eastXEnd;

private float eastYEnd;

private float southeastXEnd;

private float southeastYEnd;

private float southXEnd;

private float southYEnd;

private float southwestXEnd;

private float southwestYEnd;

private float westXEnd;

private float westYEnd;

private int currentColor = 7;

String color[] = new String[]{

“#a5a5a5”,

“#b7b7b7”,

“#c0c0c0”,

“#c9c9c9”,

“#d2d2d2”,

“#dbdbdb”,

“#e4e4e4”,

“#e4e4e4”

};

int[] colors = new int[8];

public IOSStyleLoadingView(Context context) {

this(context, null, 0);

}

public IOSStyleLoadingView(Context context, AttributeSet attrs) {

this(context, null, 0);

}

/**

提前在构造方法里调用Color.parseColor解析好数据，而不是在onDraw方法里频繁调用
@param context
@param attrs
@param defStyleAttr

public IOSStyleLoadingView(Context context, AttributeSet attrs, int defStyleAttr) {

super(context, attrs, defStyleAttr);

this.context = context;

radius = UIKits.dip2Px(context, 9);

insideRadius = UIKits.dip2Px(context, 5);

for (int i = 0; i < color.length; i++) {

colors[i] = Color.parseColor(color[i]);

}

paint.setAntiAlias(true);

paint.setStrokeWidth(UIKits.dip2Px(context, 2));

paint.setStyle(Paint.Style.STROKE);

paint.setStrokeCap(Paint.Cap.ROUND);

}

Path path = new Path();

Paint paint = new Paint();

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

path.reset();