多个图像/饼图更新

时间：2016-05-04 15:28:03

标签： android charts pie-chart android-async-http

对于阅读此帖子的人来说，这应该是一个非常有用的例子。我正在尝试创建一个异步任务，它将占用一些现有的位置，在ImageView中保存图片，并用完全相同的大小，但不同的图片替换它们。

具体来说，我想显示一些静态图片，然后使用来自远程服务器的实时数据更新它们，还可以将它们缩放到当前显示的大小。

从主要活动中，我们只需使用我们想要更新的ImageView调用它：

public class MainActivity extends Activity {

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    drawPieCharts((ImageView) findViewById(R.id.chart1),(ImageView) findViewById(R.id.chart2),(ImageView) findViewById(R.id.chart3));
}

接下来，我们需要联系服务器，使用我们的图表获取JSON对象，然后更新图像。我担心我对Java和Android的了解不够充分。这是我现在正在进行的热门话题：

public class drawPieCharts(ImageView... imageViews){

int[] COLORS={0xff00ff00,0xff00ee00,0xff00dd00,0xff00cc00,0xff000000};//alpha r g b
int[] slices={300,400,100,200,500};


@Override
    protected void onPreExecute(){
    //String charts="{\"charts\":[{\"chart\":1, \"colors\":[0,1,2,3,4], \"slices\":[300,400,100,200,500]},{\"chart\":2, \"colors\":[0,1,2,3,4], \"slices\":[200,100,400,200,500]},{\"chart\": 3, \"colors\":[0,1,2,3,4], \"slices\":[200,100,400,200,200]}]}";
   try{
        JSONObject obj = new JSONObject(charts);
        JSONArray jsonArray = obj.optJSONArray("charts");

        for(int i=0; i < jsonArray.length(); i++){
            JSONObject chartData = jsonArray.getJSONObject(i);
            JSONObject chart = chartData.optJSONObject("chart");
            JSONArray colors = chartData.optJSONArray("colors");
            JSONArray slices = chartData.optJSONArray("slices");
            new DrawPieChart(chartViews[chart]);
        }
        }catch(JSONException e){e.printStackTrace();}

     String jsonReply = "";
        try {
            URL url = new URL(url_to_server);
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

            InputStream stream = new BufferedInputStream(urlConnection.getInputStream());
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(stream));
            StringBuilder builder = new StringBuilder();

            String inputString;
            while ((inputString = bufferedReader.readLine()) != null) {
                builder.append(jsonReply);
            }

            JSONObject charts = new JSONObject(builder.toString());
            JSONObject chart = charts.getJSONObject("chart");

          urlConnection.disconnect();

        } catch (IOException | JSONException e) {
            e.printStackTrace();
        }

ImageView imageView = null;

    @Override
    protected doInBackground() {
        this.imageView = imageViews[0];
        return updateChart();
    }

    @Override
    protected void onPostExecute(Bitmap result) {
        for(
        imageView.setImageBitmap(result);
    }

private Bitmap updateChart() {
    Bitmap bmp = Bitmap.createBitmap(imageView.getDrawable().getIntrinsicHeight(),imageView.getDrawable().getIntrinsicHeight(), Bitmap.Config.ARGB_8888);//w h config

    Canvas canvas = new Canvas(bmp);
    RectF box = new RectF(2, 2,bmp.getWidth()-2 , bmp.getHeight()-2);

    //get value for 100%
    int sum = 0;
    for (int slice : slices) {
        sum += slice;
    }
    //initalize painter
    Paint paint = new Paint();
    paint.setAntiAlias(true);

    paint.setStyle(Paint.Style.STROKE);
    paint.setStrokeWidth(1f);
    paint.setStyle(Paint.Style.FILL_AND_STROKE);
    float start = 0;
    //draw slices
    for(int i =0; i < slices.length; i++){
        paint.setColor(COLORS[i]);
        float angle;
        angle = ((360.0f / sum) * slices[i]);
        canvas.drawArc(box, start, angle, true, paint);
        start += angle;
    }
    return bmp;
}
}

此处还包括布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
   >

<ImageView
    android:id="@+id/chart1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:scaleType="centerInside"
    android:adjustViewBounds="true"
    android:layout_weight="1"
    android:src="@drawable/chart_place_holder"
    />
<ImageView
android:id="@+id/chart2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
    android:scaleType="centerInside"
    android:adjustViewBounds="true"
    android:layout_weight="1"
    android:src="@drawable/chart_place_holder"
    />
<ImageView
android:id="@+id/chart3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
    android:scaleType="centerInside"
    android:adjustViewBounds="true"
    android:layout_weight="1"
    android:src="@drawable/chart_place_holder"
    />

</LinearLayout>
<TextView
android:id="@+id/textView"
android:text="data" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:layout_centerInParent="true"
android:textSize="28sp"/>

</LinearLayout>

图表已确认有效。它将获取占位符的当前大小并创建匹配的饼图，以便部分代码可以正常使用。我只是需要一些帮助，让剩下的这个混乱组织起来，这只是超出我的技能组合。

1 个答案:

答案 0 :(得分：0)

我能够自己解决这个问题。这是经过完整测试的代码。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/RootView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/bg_image">

<ScrollView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="10dp"
    android:fillViewport="false">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:background="#cc000000"
            android:orientation="horizontal"
            >

            <!-- chart title -->
            <TextView
                android:text="CHART ONE"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:scaleType="centerInside"
                android:adjustViewBounds="true"
                android:gravity="center"
                android:textSize="16sp"
                android:layout_weight="1"
                />
            <TextView
                android:text="CHART TWO"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:scaleType="centerInside"
                android:adjustViewBounds="true"
                android:gravity="center"
                android:textSize="16sp"
                android:layout_weight="1"
                />
            <TextView
                android:text="CHART THREE"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:scaleType="centerInside"
                android:adjustViewBounds="true"
                android:gravity="center"
                android:textSize="16sp"
                android:layout_weight="1"
                />

        </LinearLayout>

        <!-- charts -->
        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:background="#AA000000"
            android:gravity="center"
            >

            <ImageView
                android:id="@+id/chart_1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:scaleType="centerInside"
                android:adjustViewBounds="true"
                android:gravity="center"
                android:layout_weight="1"
                android:src="@drawable/default_piechart"
                />
            <ImageView
                android:id="@+id/chart_2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:scaleType="centerInside"
                android:adjustViewBounds="true"
                android:gravity="center"
                android:layout_weight="1"
                android:src="@drawable/default_piechart"
                />
            <ImageView
                android:id="@+id/chart_3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:scaleType="centerInside"
                android:adjustViewBounds="true"
                android:gravity="center"
                android:layout_weight="1"
                android:src="@drawable/default_piechart"
                />

        </LinearLayout>

        <!-- chart values -->
        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:background="#AA000000"
            android:orientation="horizontal"
            >

            <TextView
                android:id="@+id/chart_value_1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:scaleType="centerInside"
                android:adjustViewBounds="true"
                android:gravity="center"
                android:text="-"
                android:textSize="16sp"
                android:layout_weight="1"
                />
            <TextView
                android:id="@+id/chart_value_2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:scaleType="centerInside"
                android:adjustViewBounds="true"
                android:gravity="center"
                android:text="-"
                android:textSize="16sp"
                android:layout_weight="1"
                />
            <TextView
                android:id="@+id/chart_value_3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:scaleType="centerInside"
                android:adjustViewBounds="true"
                android:gravity="center"
                android:text="-"
                android:textSize="16sp"
        android:layout_weight="1"
        />
        </LinearLayout>
    </LinearLayout>
   </ScrollView>
</RelativeLayout>

要显示的内容：

ImageView [] chart_image = new ImageView[3];
TextView [] chart_text = new TextView[3];
chart_image[0] = (ImageView) findViewById(R.id.chart_1);
chart_image[1] = (ImageView) findViewById(R.id.chart_2);
chart_image[2] = (ImageView) findViewById(R.id.chart_3);

chart_text[0] = (TextView) findViewById(R.id.chart_value_1);
chart_text[1] = (TextView) findViewById(R.id.chart_value_2);
chart_text[2] = (TextView) findViewById(R.id.chart_value_3);

String chart_data= "\"charts\": [{ \"value\": \"Chart 1 Value\", \"colors\": [5, 6, 7, 8, 1], \"slices\": [938, 2927, 2271, 557, 5507] }, { \"value\": \"Chart 2 Value\", \"colors\": [4, 8, 1, 1], \"slices\": [5492, 41701, 1507] }, { \"value\": 9999, \"colors\": [8, 1], \"slices\": [7000, 3000] }] ";

new DrawPieCharts(chart_image, chart_text, chart_data);

现在可以从主活动中调用它：

{{1}}
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