在android中创建条形图
有没有人遇到过这个问题。现在我正试图用android显示一个条形图，但我通过使用它从web服务中获取x轴和y轴值。我通过SOAP方法来获取它。在这里我得到了这个问题，有人能告诉我如何克服这个问题吗 LOGCAT在android中创建条形图,android,web-services,bar-chart,Android,Web Services,Bar Chart,有没有人遇到过这个问题。现在我正试图用android显示一个条形图，但我通过使用它从web服务中获取x轴和y轴值。我通过SOAP方法来获取它。在这里我得到了这个问题，有人能告诉我如何克服这个问题吗 LOGCAT 09-17 10:18:09.651: W/KeyCharacterMap(339): No keyboard for id 0 09-17 10:18:09.651: W/KeyCharacterMap(339): Using default keymap: /system/usr/k
09-17 10:18:09.651: W/KeyCharacterMap(339): No keyboard for id 0
09-17 10:18:09.651: W/KeyCharacterMap(339): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
09-17 10:18:20.450: D/AndroidRuntime(339): Shutting down VM
09-17 10:18:20.450: W/dalvikvm(339): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
09-17 10:18:20.460: E/AndroidRuntime(339): FATAL EXCEPTION: main
09-17 10:18:20.460: E/AndroidRuntime(339): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.xmlparsing_test/com.example.xmlparsing_test.BarGraphActivity}: java.lang.NullPointerException
09-17 10:18:20.460: E/AndroidRuntime(339): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
09-17 10:18:20.460: E/AndroidRuntime(339): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
09-17 10:18:20.460: E/AndroidRuntime(339): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
09-17 10:18:20.460: E/AndroidRuntime(339): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
09-17 10:18:20.460: E/AndroidRuntime(339): at android.os.Handler.dispatchMessage(Handler.java:99)
09-17 10:18:20.460: E/AndroidRuntime(339): at android.os.Looper.loop(Looper.java:123)
09-17 10:18:20.460: E/AndroidRuntime(339): at android.app.ActivityThread.main(ActivityThread.java:4627)
09-17 10:18:20.460: E/AndroidRuntime(339): at java.lang.reflect.Method.invokeNative(Native Method)
09-17 10:18:20.460: E/AndroidRuntime(339): at java.lang.reflect.Method.invoke(Method.java:521)
09-17 10:18:20.460: E/AndroidRuntime(339): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
09-17 10:18:20.460: E/AndroidRuntime(339): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
09-17 10:18:20.460: E/AndroidRuntime(339): at dalvik.system.NativeStart.main(Native Method)
09-17 10:18:20.460: E/AndroidRuntime(339): Caused by: java.lang.NullPointerException
09-17 10:18:20.460: E/AndroidRuntime(339): at com.example.xmlparsing_test.BarGraphActivity.buildBarDataset(BarGraphActivity.java:120)
09-17 10:18:20.460: E/AndroidRuntime(339): at com.example.xmlparsing_test.BarGraphActivity.DrawGraph(BarGraphActivity.java:61)
09-17 10:18:20.460: E/AndroidRuntime(339): at com.example.xmlparsing_test.BarGraphActivity.onCreate(BarGraphActivity.java:26)
09-17 10:18:20.460: E/AndroidRuntime(339): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
09-17 10:18:20.460: E/AndroidRuntime(339): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
09-17 10:18:20.460: E/AndroidRuntime(339): ... 11 more
public class BarGraphActivity extends Chart
{
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main1);
Chart ch = new Chart();
DrawGraph();
}
public void DrawGraph()
{
String[] titles = new String[] { " Barcharts",""};
double[] x_axis = null;
double[] y_axis = null;
List<double[]> values = new ArrayList<double[]>();
values.add(x_axis);
values.add(y_axis);
int[] colors = new int[] { Color.WHITE, Color.BLACK};
XYMultipleSeriesRenderer renderer = buildBarRenderer(colors);
renderer.setOrientation(Orientation.HORIZONTAL);
setChartSettings(renderer, "some texts", " ", " ",0,x_axis, 0,y_axis, Color.GRAY, Color.LTGRAY);
renderer.setXLabels(1);
renderer.addXTextLabel(1, "x_axis");
renderer.addYTextLabel(1, "y_axis");
renderer.setPanEnabled(true, false);
int length = renderer.getSeriesRendererCount();
for (int i = 0; i < length; i++)
{
SimpleSeriesRenderer seriesRenderer = renderer.getSeriesRendererAt(i);
seriesRenderer.setDisplayChartValues(true);
}
ChartFactory.getBarChartIntent(this, buildBarDataset(titles, values), renderer,Type.DEFAULT);
}
protected XYMultipleSeriesRenderer buildBarRenderer(int[] colors)
{
// creates a SeriesRenderer and initializes it with useful default values as well as colors
XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();
renderer.setAxisTitleTextSize(15);
renderer.setChartTitleTextSize(20);
renderer.setLabelsTextSize(15);
renderer.setLegendTextSize(15);
int length = colors.length;
for (int i = 0; i < length; i++)
{
SimpleSeriesRenderer r = new SimpleSeriesRenderer();
r.setColor(colors[i]);
renderer.addSeriesRenderer(r);
}
return renderer;
}
protected void setChartSettings(XYMultipleSeriesRenderer renderer, String title, String xTitle,
String yTitle, double xMin, double[] x_axis, double yMin, double[] y_axis, int axesColor,int labelsColor)
{
// sets lots of default values for this renderer
renderer.setChartTitle(title);
renderer.setXTitle(xTitle);
renderer.setYTitle(yTitle);
renderer.setXAxisMin(xMin);
renderer.setYAxisMin(yMin);
renderer.setAxesColor(axesColor);
renderer.setLabelsColor(labelsColor);
renderer.setApplyBackgroundColor(true);
renderer.setBackgroundColor(Color.BLACK);
}
protected XYMultipleSeriesDataset buildBarDataset(String[] titles, List<double[]> values)
{
// adds the axis titles and values into the dataset
XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
int length = titles.length;
for (int i = 0; i < length; i++)
{
CategorySeries series = new CategorySeries(titles[i]);
double[] v = values.get(i);
int seriesLength = v.length;
for (int k = 0; k < seriesLength; k++)
{
series.add(v[k]);
}
dataset.addSeries(series.toXYSeries());
}
return dataset;
} }
公共类BarGraphActivity扩展图表
{
创建时的公共void（Bundle savedInstanceState）
{
super.onCreate（savedInstanceState）；
setContentView（R.layout.main1）；
图表ch=新图表（）；
绘图（）；
}
public void DrawGraph（）
{
String[]titles=新字符串[]{“条形图”，“”}；
双[]x_轴=空；
双[]y_轴=空；
列表值=新的ArrayList（）；
值。添加（x_轴）；
值。添加（y_轴）；
int[]colors=newint[]{Color.WHITE，Color.BLACK}；
XYMultipleReseriesRenderer渲染器=构建渲染器（颜色）；
渲染器.setOrientation（方向.水平）；
setChartSettings（渲染器，“某些文本”、“0”、“0、x_轴、0、y_轴、Color.GRAY、Color.LTGRAY）；
setXLabels（1）；
renderer.addxtlabel（1，“x_轴”）；
渲染器.addYTextLabel（1，“y_轴”）；
renderer.setPanEnabled（真、假）；
int length=renderer.getSeriesRenderCount（）；
for（int i=0；i谢谢你宝贵的时间 还有其他方法可以绘制图形，您是只需要这种方法还是需要其他方法。？
如果是，我将使用新的
条形图活动编辑我的答案