在画布上画圆模拟动画android答案

【问题标题】：Draw circle on canvas simulating animation android在画布上画圆模拟动画android
【发布时间】：2015-08-07 23:09:33
【问题描述】：

我需要画一个空白的圆圈，边距为 10 像素。我遇到的问题是我需要在 2 秒内模拟圆的绘制，然后开始在它的顶部绘制另一个颜色的圆。我正在使用自定义视图，并且尝试将我的逻辑实现到 onDraw 方法中，并每 50 毫秒使视图无效。问题是我无法画圆……我只画蹩脚的数字。有人知道我如何在不使用 canvas.drawCircle 方法的情况下绘制一个圆圈，因为该方法直接绘制圆圈而不使用动画。

我当前的代码

 public class CustomAnimationView  extends View{

private Canvas canvas;
private int count = 0;
private Paint paint;
private int mLeft;
private int mRight;
private int mBottom;
private int mTop;


public CustomAnimationView(Context context) {
    super(context);
}

public CustomAnimationView(Context context, AttributeSet attrs) {
    super(context, attrs);
}

public CustomAnimationView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    setAttributes(attrs);
}

private void setAttributes(AttributeSet attrs) {
}

protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    this.canvas = canvas;

    if(paint == null){
        paint  = new Paint();
        paint.setAntiAlias(true);
        paint.setStyle(Style.STROKE);
        paint.setStrokeWidth(10);
        paint.setColor(Color.BLACK);
    }

    if(count<150){
            drawFirstQuarter(count);
    }

    count++;
}

public void drawFirstQuarter(int count){
     RectF oval = new RectF(mLeft, mTop, mRight, mBottom);
     canvas.drawArc(oval, 90, 30, true, paint);
}


public void setRect(int top, int bottom, int left, int right){
    mBottom = bottom;
    mTop = top;
    mLeft = left;
    mRight = right;
}

}

现在我只是想画一个圆圈。

【问题讨论】：

你能发布你当前自定义视图的代码吗？

标签： android animation android-canvas

【解决方案1】：

谢谢。我已经解决了。这是一个代码示例

public class CustomAnimationView extends View{

    private Canvas canvas;
    private int mCount = 0;
    private Paint paint1;
    private Paint paint2;
    private RectF oval1;
    private Context context;
    private int mColorCount = 0;

    public CustomAnimationView(Context context) {
        super(context);
        this.context = context;
    }

    public CustomAnimationView(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.context = context;
    }

    public CustomAnimationView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        this.context = context;
        setAttributes(attrs);
    }

    private void setAttributes(AttributeSet attrs) {
    }

    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        this.canvas = canvas;

        if(paint1 == null){
            paint1  = new Paint();
            paint1.setAntiAlias(true);
            paint1.setStyle(Style.STROKE);
            paint1.setStrokeWidth(10);
        }

        if(paint2 == null){
            paint2  = new Paint();
            paint2.setAntiAlias(true);
            paint2.setStyle(Style.STROKE);
            paint2.setStrokeWidth(10);
        }


        if(mCount % 360 == 0 ){
            mColorCount++;
        }

        if(mColorCount % 2 == 0){
            paint1.setColor(context.getResources().getColor(R.color.white));
            paint2.setColor(context.getResources().getColor(R.color.black));
        }else{
            paint2.setColor(context.getResources().getColor(R.color.white));
            paint1.setColor(context.getResources().getColor(R.color.black));
        }

        if(oval1 == null)
            oval1 = new RectF(5,5,canvas.getWidth()-5, canvas.getHeight()-5);

        drawFirstQuarter(mCount, oval1);

    }

    public void drawFirstQuarter(int count, RectF oval){
         canvas.drawArc(oval, 90, 360, false, paint2);
         canvas.drawArc(oval, 90, count, false, paint1);
         if(mCount == 330)
             mCount = 0;
         else
             mCount += 30;
    }

}

【讨论】：