当前位置 博文首页 > 狂发飘飘：android之cpu使用率曲线效果的实现！
最近做一个效果：在手机设置里面“关于手机”里面添加一项来显示当前手机cpu使用率的曲线！其实现效果如下图所示：
上图关于手机的第一项就是我要实现的效果！今天来讲讲这个曲线的view（cpu_speedcurve_view）是如何实现的！
首先要注意以下几点：
（1）由于我设计的cpu_speedcurve_view不仅仅显示动态的曲线，还需要用textview显示一些cpu相关信息！所以，我选择cpu_speedcurve_view继承一个viewgroup，这里我选择的是FrameLayout
（3）曲线的怎么绘制？
?????????? 这里我是在cpu_speedcurve_view的public void draw(Canvas canvas)里面用Canvas的drawPath来绘制的。具体代码如下：
public void draw(Canvas canvas) {
super.draw(canvas);
//mPaint.setColor(coordinateColor);
//mPaint.setStrokeWidth(mStrokeSize*2);
//canvas.drawPath(m_path_coordinate, mPaint);
//canvas.clipRect(10, 10, 5, 5);
if(flag_start){
if(m_path_0 == null && m_path_1 == null){
//Start_run_CpuTracker_to_show_curve();
}else{
mPaint.setColor(curveColor);
mPaint.setStrokeWidth(mStrokeSize);
if(m_path_0 != null){
// Log.d("speedcurve", "cpu_speedcurve_view draw (m_path != null) ");
if(!m_path_0.isEmpty()){
canvas.drawPath(m_path_0, mPaint);
}
}
if(m_path_1 != null){
// Log.d("speedcurve", "cpu_speedcurve_view draw (m_path != null) ");
if(!m_path_1.isEmpty()){
canvas.drawPath(m_path_1, mPaint);
}
}
}
}
} private Path m_path_0;
private Path m_path_1;（2）对于曲线的动态显示，我的办法是定义一个Handler定时的自动发送信息来更新cpu运行的数据，最后用invalidate();来刷新曲线：
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case 000:
m_CpuTracker.update();
TotalCpuPercent = m_CpuTracker.getTotalCpuPercent();
int h = view_h - 2;
//int CpuPercent_po = (int) (h * TotalCpuPercent);
if(flag_num < 400){
if(m_path_0 == null){
m_path_0 = new Path();
m_path_0.moveTo(view_w+4, h - TotalCpuPercent);
}
if(flag_num > 200){
if(m_path_1 == null){
m_path_1 = new Path();
m_path_1.moveTo(view_w+4, h - TotalCpuPercent);
}
}else{
m_path_1 = null;
}
}else if(flag_num < 600){
m_path_0 = null;
if(m_path_1 == null){
m_path_1 = new Path();
m_path_1.moveTo(view_w+4, h - TotalCpuPercent);
}
}else if(flag_num < 800){
if(m_path_0 == null){
m_path_0 = new Path();
m_path_0.moveTo(view_w+4, h - TotalCpuPercent);
}
}else{
flag_num = 0;
}
if(m_path_0 != null){
m_path_0.lineTo(view_w+4, h - TotalCpuPercent);
matrix.setTranslate(-4,0);
m_path_0.transform(matrix);
}
if(m_path_1 != null){
m_path_1.lineTo(view_w+4, h - TotalCpuPercent);
matrix.setTranslate(-4,0);
m_path_1.transform(matrix);
}
// Log.d("speedcurve", "cpu_speedcurve_view handleMessage msg.what=000 flag_num="+flag_num);
// Log.d("speedcurve", "cpu_speedcurve_view handleMessage TotalCpuPercent="+TotalCpuPercent+"view_h="+view_h+"getCurCpuFreq()="+Cpu_info_manager.getCurCpuFreq());
if(flag_start){
mHandler.sendEmptyMessageDelayed(000,300);
invalidate();
flag_num++;
}else{
Stop_run_CpuTracker_to_show_curve();
}
break;
case 111:
break;
}
}
};（3）如何获取cpu的使用率呢？
????? 用android提供的ProcessCpuTracker就可以了。
m_CpuTracker = new ProcessCpuTracker(false);（4）最后记得 在这个里面 protected void onDetachedFromWindow()停止运行就可以了！
就这样问题就基本解决了！如果要实现如上的效果图的则需要定义一个PreferenceGroup：
PreferenceGroup mCPUStatusPref = (PreferenceGroup) findPreference("cpu_key");
mCPUStatusPref.setLayoutResource(R.layout.cpu_curve_preference); <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="85dip"
android:gravity="center_vertical"
android:paddingStart="@*android:dimen/preference_item_padding_side"
android:paddingEnd="?android:attr/scrollbarSize"
android:background="?android:attr/selectableItemBackground"
android:paddingTop="6dip"
android:paddingBottom="6dip">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:paddingTop="6dip"
android:paddingBottom="6dip">
<TextView
android:id="@+android:id/title"
android:text="@string/XunHu_Setting_Cpu_Info"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:singleLine="true"
android:textAppearance="?android:attr/textAppearanceMedium"
android:ellipsize="marquee"
android:fadingEdge="horizontal" />
<TextView
android:id="@android:id/summary"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/usage_type_cpu_foreground"
android:layout_below="@android:id/title"
android:layout_alignStart="@android:id/title"
android:visibility="gone"
android:textAppearance="?android:attr/textAppearanceSmall"
android:textColor="?android:attr/textColorSecondary"
android:maxLines="4" />
</RelativeLayout>
<com.android.settings.widget.cpu_speedcurve_view
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:minWidth="180dip"
android:background="@drawable/cpu_curve_bg"
android:layout_marginBottom="8dip"
android:layout_marginTop="8dip"
>
<TextView
android:id="@+android:id/cpu_speedcurve_view_title"
android:text="@string/XunHu_Setting_Cpu_Info_util"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:singleLine="true"
android:ellipsize="marquee"
android:fadingEdge="horizontal" />
</com.android.settings.widget.cpu_speedcurve_view>
</LinearLayout>
