Android Hongyang博客自定义View练习与优化

###所写内容基本来自Hongyang的CSDN博客，以及练习时可以优化处进行优化：> 对应GitHub地址：[https://github.com/youlookwhat/CustomViewStudy](https://github.com/youlookwhat/CustomViewStudy)###一. 博客目录：####1. [Android 自定义View (一)](http://blog.csdn.net/lmj623565791/article/details/24252901)####2. [Android 自定义View (二) 进阶](http://blog.csdn.net/lmj623565791/article/details/24300125)####3. [Android 自定义View (三) 圆环交替 等待效果](http://blog.csdn.net/lmj623565791/article/details/24500107)####4. [Android 自定义View (四) 视频音量调控](http://blog.csdn.net/lmj623565791/article/details/24529807)####5. [Android 手把手教您自定义ViewGroup（一）](http://blog.csdn.net/lmj623565791/article/details/38339817)####6. [Android 深入理解Android中的自定义属性](http://blog.csdn.net/lmj623565791/article/details/45022631)####7. [Android ViewDragHelper完全解析 自定义ViewGroup神器](http://blog.csdn.net/lmj623565791/article/details/46858663)—###二. 主要源码 >- 1.[CustomTitleView.java](https://github.com/youlookwhat/CustomViewStudy/blob/master/app/src/main/java/com/example/jingbin/customview/view/CustomTitleView.java)>- 2.[CustomImageView.java](https://github.com/youlookwhat/CustomViewStudy/blob/master/app/src/main/java/com/example/jingbin/customview/view/CustomImageView.java)>- 3.[CustomProgressBar.java](https://github.com/youlookwhat/CustomViewStudy/blob/master/app/src/main/java/com/example/jingbin/customview/view/CustomProgressBar.java)>- 4.[CustomVolumControlBar.java](https://github.com/youlookwhat/CustomViewStudy/blob/master/app/src/main/java/com/example/jingbin/customview/view/CustomVolumControlBar.java)>- 5.[CustomImgContainer.java](https://github.com/youlookwhat/CustomViewStudy/blob/master/app/src/main/java/com/example/jingbin/customview/viewgroup/CustomImgContainer.java)>- 6.[DeepUnderstandAttrActivity.java](https://github.com/youlookwhat/CustomViewStudy/blob/master/app/src/main/java/com/example/jingbin/customview/activity/DeepUnderstandAttrActivity.java)>- 7.[VDHDeepLayout.java](https://github.com/youlookwhat/CustomViewStudy/blob/master/app/src/main/java/com/example/jingbin/customview/viewgroup/VDHDeepLayout.java)—###三. 项目图片（部分）

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四. 代码优化

1. CustomTitleView优化

1.1 关于文字显示优化：

//             int textWidth = mRect.width(); // 这样mRect.width()直接计算出来的会有误差               float textWidth = mPaint.measureText(mTitleText);//              int textHeight = mRect.height(); //直接计算出来的会有误差                Paint.FontMetrics fontMetrics = mPaint.getFontMetrics();                float textHeight = Math.abs((fontMetrics.bottom - fontMetrics.top));

1.2 onDraw里画Text时起点坐标优化：

canvas.drawText(mTitleText, getWidth() / 2 - mRect.width() / 2 - mRect.left, getHeight() / 2 + mRect.height() / 2, mPaint);

canvas.drawText(String text,float x,float y,Paint paint); x和y是绘制时的起点坐标(左下角);

” - mRect.left”: 就很标准，居中显示(csdn:yql_running解决)

1.3 参考文档

• 1.Android 自定义View-怎么绘制居中文本？
• 2.Android的DrawText详解

2. 圆环交替 等待效果优化

2.1 新开线程画线，离开页面时线程未关闭优化

// 用来开关线程    private boolean isContinue;    // 绘图线程        new Thread() {            public void run() {                while (isContinue) {                    mProgress++;                    if (mProgress == 360) {                        mProgress = 0;                        isNext = !isNext;                    }                    Log.e("--------", "在执行..");                    postInvalidate();                    try {                        Thread.sleep(100 / mSpeed);// 这里优化了一下,值越大,速度越快                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                }            }        }.start();

Activity相关代码：

@Override    protected void onStop() {        super.onStop();        customProgressBar01.setContinue(false);        customProgressBar02.setContinue(false);        customProgressBar03.setContinue(false);    }

2.2 用户宽高若设置wrap_content时优化

@Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {//        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        int modeWidth = MeasureSpec.getMode(widthMeasureSpec);        int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);        if (modeWidth == MeasureSpec.EXACTLY) {            width = sizeWidth;        } else {//默认宽度200dp            width = (int) getContext().getResources().getDimension(R.dimen.width);        }        Log.e("------------->", "width:" + width);        setMeasuredDimension(width, width);    }

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五. Thanks

• CSDN:张鸿洋