MPAndroidChat的PieChart和BarChart学习

先把要写的写下来，有时间再详写

    之前学MPAndroidChat主要看了这个人的博文http://blog.csdn.net/shineflowers/article/details/44809119，但是发现和github上的内容有出入，仔细研究了后发现github上的代码原来一直在更新，博主只是因为版本低所以不一样，所以我从github上导出工程后再导出jar包就是最新的了。

   下面的中文说明http://www.jianshu.com/p/c049389d348a?nomobile=yes

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    今天算是有时间了 ，抽点时间把图表内容总结一下，有部分是copy上述引用博文的，有部分是自己总结的，代码如下：

饼型图：

package myapp.charttest;

import java.util.ArrayList;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;

import com.github.mikephil.charting.charts.PieChart;
import com.github.mikephil.charting.components.Legend;
import com.github.mikephil.charting.data.Entry;
import com.github.mikephil.charting.data.PieData;
import com.github.mikephil.charting.data.PieDataSet;

public class PieGraphActivity extends Activity {
PieChart pieChart;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pie_graph);
init();
setChart();
}

public void init(){
pieChart=(PieChart)findViewById(R.id.pie_chart);
}

public void setChart(){

//名字
ArrayList<String> names=new ArrayList<String>();
names.add("used");
names.add("left");
//大小
ArrayList<Entry> sizes=new ArrayList<Entry>();
sizes.add(new Entry(10,0));
sizes.add(new Entry(90,1));
//颜色
ArrayList<Integer> colors=new ArrayList<Integer>();
colors.add(Color.parseColor("#FFBB33"));
colors.add(Color.parseColor("#CCCCCC"));

PieDataSet pieDataSet=new PieDataSet(sizes,"");//参数：颜色栏显示颜色目录、
//pieDataSet.setDrawValues(false);//是否在块上面显示值以及百分百
//pieDataSet.setSliceSpace(0f);//块间距
pieDataSet.setColors(colors);

//Displa
4000
yMetrics metrics=this.getResources().getDisplayMetrics();
PieData pieData=new PieData(names,pieDataSet);

pieChart.setTransparentCircleRadius(0f);//设置大圆里面透明小圆半径，和洞不是一个圆

pieChart.setDrawHoleEnabled(true);
//pieChart.setHoleColorTransparent(true);//设置中心洞是否透明：true为黑，false为白
pieChart.setHoleRadius(0f);//设置大圆里面的无色圆的半径（洞...）

pieChart.setDescription("");//参数：右下角显示图形描述

pieChart.setDrawCenterText(false);//不显示图中心文字
pieChart.setCenterText("traffic graph");//图中心文字
pieChart.setRotationEnabled(false);//不能手动旋转

//pieChart.setDrawMarkerViews(false);
//pieChart.setDrawSliceText(false);//块的文本是否显示

pieChart.setData(pieData);

Legend legend=pieChart.getLegend();
legend.setEnabled(false);//是否显示图形说明，必须要放在setData后,否则出错

//两个参数有不同的意思：
//durationMillisX：每个块运行到固定初始位置的时间
//durationMillisY: 每个块到绘制结束时间
pieChart.animateXY(1000, 1000);//设置动画（参数为时间）

}

}

显示结果：


直方图：

package myapp.charttest;

import java.util.ArrayList;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.WindowManager;

import com.github.mikephil.charting.charts.BarChart;
import com.github.mikephil.charting.components.Legend;
import com.github.mikephil.charting.components.XAxis;
import com.github.mikephil.charting.components.XAxis.XAxisPosition;
import com.github.mikephil.charting.components.YAxis;
import com.github.mikephil.charting.components.YAxis.YAxisLabelPosition;
import com.github.mikephil.charting.data.BarData;
import com.github.mikephil.charting.data.BarDataSet;
import com.github.mikephil.charting.data.BarEntry;

public class RecGraphActivity extends Activity {
BarChart barChart;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);

setContentView(R.layout.activity_rec_graph);
init();
setData();
}

public void init(){
barChart=(BarChart)findViewById(R.id.bar_chart);
}

public void setData(){
//名称
ArrayList<String> names=new ArrayList<String>();
names.add("1月1日");
names.add("1月2日");
names.add("1月3日");
names.add("1月4日");
names.add("1月5日");
names.add("1月6日");
names.add("1月7日");
names.add("1月8日");
names.add("1月9日");
//大小（高低）
ArrayList<BarEntry> sizes=new ArrayList<BarEntry>();
sizes.add(new BarEntry(80,0));
sizes.add(new BarEntry(70,1));
sizes.add(new BarEntry(60,2));
sizes.add(new BarEntry(50,3));
sizes.add(new BarEntry(40,4));
sizes.add(new BarEntry(30,5));
sizes.add(new BarEntry(20,6));
sizes.add(new BarEntry(10,7));
sizes.add(new BarEntry(0,8));

//颜色
BarDataSet barDataSet=new BarDataSet(sizes,"");
barDataSet.setColor(Color.parseColor("#FFBB33"));

BarData barData=new BarData(names,barDataSet);

barChart.setDescription("");//数据描述
barChart.setNoDataTextDescription("No Data");//没有数据时显示

//barChart.setDragEnabled(false);//拖拽（蛋疼）

barChart.setScaleEnabled(true);//手动缩放效果
barChart.setPinchZoom(false);//xy轴同时缩放,和setScaleEnabled一起使用

barChart.setHighlightPerTapEnabled(true);//按下时高亮显示

//barChart.setDrawGridBackground(false);
//barChart.setDrawBorders(false);//画布边框

//barChart.setVisibleXRange(7);
//barChart.setMaxVisibleValueCount(6);
barChart.setDrawBarShadow(false);//设置矩形阴影不显示
barChart.setBackgroundColor(Color.parseColor("#FFFFFF"));//设置背景颜色

barChart.setMinOffset(0);//=padding
barChart.setDrawValueAboveBar(true);

barChart.setData(barData);
barChart.animateXY(1000, 1000);//设置动画

Legend legend=barChart.getLegend();//取消图形说明
legend.setEnabled(false);

//获取X轴坐标
XAxis xAxis=barChart.getXAxis();
xAxis.setPosition(XAxisPosition.BOTTOM);//X坐标位于图标底部
xAxis.setDrawGridLines(false);
xAxis.setSpaceBetweenLabels(2);//设置名字names之间的间距
//xAxis.

//获取Y轴右坐标
YAxis yAxisR=barChart.getAxisRight();
yAxisR.setEnabled(false);
yAxisR.setDrawGridLines(false);

//获取Y轴左坐标
YAxis yAxisL=barChart.getAxisLeft();
yAxisL.setEnabled(false);
yAxisL.setDrawGridLines(false);
}
}

显示结果：


遇到的相关问题：

    1：barChart的横坐标值没有显示。原因：视图中图表控件高度是match_parent，需要增加属性android:layout_marginBottom="35dp"（或者其他值）

    2：怎么初始化直方图上出现柱子个数，以及柱子宽度。(悲剧,看源码都看晕了，还是没弄懂555....)
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    大叫好，今天又有时间写博文了，之前上传了图片没看，今天一瞧真TM大，尴尬了......

     嗯，继续解决上述第二个问题，今天看了一天的源代码，是在没有找到能够初始化柱子的函数，悲剧，所以只能从其他方法入手，我的想法是让柱子的总数一定，比如30天，有30个数据，但是我要它只显示7个数据，我们可以让直方图放大四倍，这样显示在屏幕上的就是7个数据了，好了有了目标就可以动手了

    首先我们发现直方图自己就有缩放功能，于是我们看看能不能修改源代码，自己新增一下借口和改一下源代码：

    这段代码是在BarLineChartTouchListener类中，处理触摸事件

public boolean onTouch(View v, MotionEvent event) {

if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);

if (event.getActionMasked() == MotionEvent.ACTION_CANCEL) {
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}

if (mTouchMode == NONE) {
mGestureDetector.onTouchEvent(event);
}

if (!mChart.isDragEnabled() && (!mChart.isScaleXEnabled() && !mChart.isScaleYEnabled()))
return true;

// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK) {

case MotionEvent.ACTION_DOWN:

startAction(event);

stopDeceleration();

saveTouchStart(event);

break;
case MotionEvent.ACTION_POINTER_DOWN:

if (event.getPointerCount() >= 2) {

mChart.disableScroll();

saveTouchStart(event);

// get the distance between the pointers on the x-axis
mSavedXDist = getXDist(event);

// get the distance between the pointers on the y-axis
mSavedYDist = getYDist(event);

// get the total distance between the pointers
mSavedDist = spacing(event);

if (mSavedDist > 10f) {

if (mChart.isPinchZoomEnabled()) {
mTouchMode = PINCH_ZOOM;
} else {
if (mSavedXDist > mSavedYDist)
mTouchMode = X_ZOOM;
else
mTouchMode = Y_ZOOM;
}
}

// determine the touch-pointer center
midPoint(mTouchPointCenter, event);
}
break;
case MotionEvent.ACTION_MOVE:

if (mTouchMode == DRAG) {

mChart.disableScroll();
performDrag(event);

} else if (mTouchMode == X_ZOOM || mTouchMode == Y_ZOOM || mTouchMode == PINCH_ZOOM) {

mChart.disableScroll();

if (mChart.isScaleXEnabled() || mChart.isScaleYEnabled())
performZoom(event);

} else if (mTouchMode == NONE
&& Math.abs(distance(event.getX(), mTouchStartPoint.x, event.getY(),
mTouchStartPoint.y)) > 5f) {

if (mChart.hasNoDragOffset()) {

if (!mChart.isFullyZoomedOut() && mChart.isDragEnabled()) {
mTouchMode = DRAG;
} else {

mLastGesture = ChartGesture.DRAG;

if (mChart.isHighlightPerDragEnabled())
performHighlightDrag(event);
}

} else if (mChart.isDragEnabled()) {
mLastGesture = ChartGesture.DRAG;
mTouchMode = DRAG;
}
}
break;

case MotionEvent.ACTION_UP:

final VelocityTracker velocityTracker = mVelocityTracker;
final int pointerId = event.getPointerId(0);
velocityTracker.computeCurrentVelocity(1000, Utils.getMaximumFlingVelocity());
final float velocityY = velocityTracker.getYVelocity(pointerId);
final float velocityX = velocityTracker.getXVelocity(pointerId);

if (Math.abs(velocityX) > Utils.getMinimumFlingVelocity() ||
Math.abs(velocityY) > Utils.getMinimumFlingVelocity()) {

if (mTouchMode == DRAG && mChart.isDragDecelerationEnabled()) {

stopDeceleration();

mDecelerationLastTime = AnimationUtils.currentAnimationTimeMillis();
mDecelerationCurrentPoint = new PointF(event.getX(), event.getY());
mDecelerationVelocity = new PointF(velocityX, velocityY);

Utils.postInvalidateOnAnimation(mChart); // This causes computeScroll to fire, recommended for this by Google
}
}

if (mTouchMode == X_ZOOM ||
mTouchMode == Y_ZOOM ||
mTouchMode == PINCH_ZOOM ||
mTouchMode == POST_ZOOM) {

// Range might have changed, which means that Y-axis labels
// could have changed in size, affecting Y-axis size.
// So we need to recalculate offsets.
mChart.calculateOffsets();
mChart.postInvalidate();
}

mTouchMode = NONE;
mChart.enableScroll();

if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}

endAction(event);

break;
case MotionEvent.ACTION_POINTER_UP:
Utils.velocityTrackerPointerUpCleanUpIfNecessary(event, mVelocityTracker);

mTouchMode = POST_ZOOM;
break;

case MotionEvent.ACTION_CANCEL:

mTouchMode = NONE;
endAction(event);
break;
}

// Perform the transformation, update the chart
// if (needsRefresh())
mMatrix = mChart.getViewPortHandler().refresh(mMatrix, mChart, true);

return true; // indicate event was handled
}    然后缩放时间由performZoom(event)方法执行，其实在这里我们就看到了一个单词Zoom，查了一下，其含义是:基于图像缩放的新算法研究与应用（有道词典）,然后继续看代码
private void performZoom(MotionEvent event) {

if (event.getPointerCount() >= 2) {

OnChartGestureListener l = mChart.getOnChartGestureListener();

// get the distance between the pointers of the touch
// event
float totalDist = spacing(event);

if (totalDist > 10f) {

// get the translation
PointF t = getTrans(mTouchPointCenter.x, mTouchPointCenter.y);

// take actions depending on the activated touch
// mode
if (mTouchMode == PINCH_ZOOM) {

mLastGesture = ChartGesture.PINCH_ZOOM;

float scale = totalDist / mSavedDist; // total scale

boolean isZoomingOut = (scale < 1);
boolean canZoomMoreX = isZoomingOut ?
mChart.getViewPortHandler().canZoomOutMoreX() :
mChart.getViewPortHandler().canZoomInMoreX();

float scaleX = (mChart.isScaleXEnabled()) ? scale : 1f;
float scaleY = (mChart.isScaleYEnabled()) ? scale : 1f;

if (mChart.isScaleYEnabled() || canZoomMoreX) {
Log.v("performZoom", "PINCH_ZOOM :scaleX:"+scaleX+" scaleY "+scaleY);
mMatrix.set(mSavedMatrix);
mMatrix.postScale(scaleX, scaleY, t.x, t.y);
if (l != null){
l.onChartScale(event, scaleX, scaleY);

}

}

} else if (mTouchMode == X_ZOOM && mChart.isScaleXEnabled()) {

mLastGesture = ChartGesture.X_ZOOM;

float xDist = getXDist(event);
float scaleX = xDist / mSavedXDist; // x-axis scale

boolean isZoomingOut = (scaleX < 1);
boolean canZoomMoreX = isZoomingOut ?
mChart.getViewPortHandler().canZoomOutMoreX() :
mChart.getViewPortHandler().canZoomInMoreX();

if (canZoomMoreX) {

mMatrix.set(mSavedMatrix);
mMatrix.postScale(scaleX, 1f, t.x, t.y);
Log.v("performZoom", "scaleX:"+scaleX);
Log.v("performZoom", "l!=null:"+(l != null));
Log.v("performZoom", "isZoomingOut:"+isZoomingOut);
Log.v("performZoom", "canZoomMoreX:"+canZoomMoreX);
Log.v("performZoom", "class :"+this.getClass().getName());
if (l != null){
l.onChartScale(event, scaleX, 1f);
Log.v("performZoom", "onChartScale :scaleX:"+scaleX);
Log.v("performZoom", "class ::"+this.getClass().getName());

b1a0
}

}

} else if (mTouchMode == Y_ZOOM && mChart.isScaleYEnabled()) {

mLastGesture = ChartGesture.Y_ZOOM;

float yDist = getYDist(event);
float scaleY = yDist / mSavedYDist; // y-axis scale

mMatrix.set(mSavedMatrix);

// y-axis comes from top to bottom, revert y
mMatrix.postScale(1f, scaleY, t.x, t.y);

if (l != null)
l.onChartScale(event, 1f, scaleY);
}
}
}
}    缩放方法最后执行到了

l.onChartScale(event, 1f, scaleY);

这一句，然后。。。就没有然后了，找不到这句函数的实现位置，只找到了借口，啊.......
    虽然线索断了，但是也不能就此放弃，这个过程中我们知道了一个单词Zoom，咦，是不是有点熟悉，在BarChart的方法中好像有这些方法，嗯，没错：

/**
* Zooms in by 1.4f, into the charts center. center.
*/
public void zoomIn() {
Matrix save = mViewPortHandler.zoomIn(getWidth() / 2f, -(getHeight() / 2f));
mViewPortHandler.refresh(save, this, true);

// Range might have changed, which means that Y-axis labels
// could have changed in size, affecting Y-axis size.
// So we need to recalculate offsets.
calculateOffsets();
postInvalidate();
}

/**
* Zooms out by 0.7f, from the charts center. center.
*/
public void zoomOut() {
Matrix save = mViewPortHandler.zoomOut(getWidth() / 2f, -(getHeight() / 2f));
mViewPortHandler.refresh(save, this, true);

// Range might have changed, which means that Y-axis labels
// could have changed in size, affecting Y-axis size.
// So we need to recalculate offsets.
calculateOffsets();
postInvalidate();
}

/**
* Zooms in or out by the given scale factor. x and y are the coordinates
* (in pixels) of the zoom center.
*
* @param scaleX if < 1f --> zoom out, if > 1f --> zoom in
* @param scaleY if < 1f --> zoom out, if > 1f --> zoom in
* @param x
* @param y
*/
public void zoom(float scaleX, float scaleY, float x, float y) {
Matrix save = mViewPortHandler.zoom(scaleX, scaleY, x, -y);
mViewPortHandler.refresh(save, this, true);

// Range might have changed, which means that Y-axis labels
// could have changed in size, affecting Y-axis size.
// So we need to recalculate offsets.
calculateOffsets();
postInvalidate();
}    似乎可以叹口气了，答案就在这里，我们直接调用barChart.zoom(4,1,0,0);方法，就可实现我们的目的了


    （虽然过程似乎超乎意料，但是结果像是也在情理之中，就这样把）