多图像/饼图更新

Question

对于阅读此线程的人来说，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，它将在ImageView中的一些现有位置放置图片，并用完全相同但不同的图片替换它们。

具体来说，我想显示一些静态图片，然后用远程服务器的实时数据更新它们，但也要将它们缩放到当前显示的大小。

从主要活动来看，我们只需将其与我们想要更新的ImageView称为：

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，获取带有图表的JSON对象，并更新图像。恐怕我对Java和Android的了解还不够，无法将它们结合在一起。这就是我现在正在进行的最热门的混乱：

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，并创建一个匹配的饼图，这样部分代码就可以了。我只需要一点帮助就可以把剩下的事情整理好，这简直超出了我的能力范围。

Answer 1

我可以自己解决。这是经过测试的完整代码。

public class DrawPieCharts{
private final int[] COLORS = {0xff000000, 0xaa000000, 0xffff0000, 0xffff8800, 0xffffff00, 0xff00ff00, 0xff00dd00, 0xff00bb00, 0xff009900};//alpha r g b
ImageView[]chart_image=new ImageView[3];
TextView[]chart_text=new TextView[3];
String chart_data;
int[]chart_labels=new int[3];

public DrawPieCharts(ImageView[] chart_image, TextView[] chart_text, String chart_data){
    this.chart_image=chart_image;
    this.chart_text=chart_text;
    this.chart_data=chart_data;
     if(chart_data == null){return;}
    try{
        JSONObject obj = new JSONObject(chart_data);      // String charts="{"charts":[{"chart_value":10000, "colors":[4,5,6,7,0], "slices":[3000,3500,2500,1000,300]},{"chart_value":5000, "colors":[1,4,0], "slices":[4000,4500,300]},{"chart_value": 54.2, "colors":[4,0], "slices":[6000,4000]}]}";
        JSONArray jcharts = obj.getJSONArray("charts");
        for (int i = 0; i < jcharts.length(); i++){
            JSONObject chartData = jcharts.getJSONObject(i);
            chart_labels[i] = chartData.getInt("value");
            //convert to normal array
            JSONArray jcolors = chartData.getJSONArray("colors");
            int[] colors = new int[jcolors.length()];
            for (int c = 0; c < jcolors.length(); c++){
                colors[c] =COLORS[jcolors.getInt(c)];
            }
            //convert to normal array
            JSONArray jslices = chartData.getJSONArray("slices");
            int[] slices = new int[jslices.length()];
            for (int s = 0; s < jslices.length(); s++){
                slices[s] = jslices.getInt(s);
            }
            // Draw pie chart
            DrawPieChart(chart_image[i], chart_text[i], colors, slices, String.valueOf(chart_labels[i]));
        }
    } catch (JSONException e){
        e.printStackTrace();
    };
}
private void DrawPieChart(ImageView ImageView,TextView TextView, int [] colors,int [] slices, String label){
    Bitmap bmp = Bitmap.createBitmap(ImageView.getDrawable().getIntrinsicHeight(),ImageView.getDrawable().getIntrinsicHeight(), Bitmap.Config.ARGB_8888);//w h config
    float scale = bmp.getDensity();
    Canvas canvas = new Canvas(bmp);
    int width=bmp.getWidth()-2;
    int height=bmp.getHeight()-2;
    int centerX=width/2;
    int centerY=height/2;
    RectF box = new RectF(2,2,width,height);
    //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 = -90;//start at top of pie
    //draw slices
    for(int i =0; i < slices.length; i++){
        paint.setColor(colors[i]);
        float angle;
        angle = ((360f / sum) * slices[i]);
        canvas.drawArc(box, start, angle, true, paint);
        paint.setColor(0xFF000000);
        start += angle;
    }
    start = -90;//start at top of pie
    //draw labels - Must be drawn on top of slices
    for(int i =0; i < slices.length-1; i++){
        float angle;
        angle = ((360f / sum) * slices[i]);
        paint.setColor(0xFF000000);
        paint.setTextAlign(Paint.Align.CENTER);
        paint.setTextSize((int) (scale/3));// text size in pixels
        //paint.setShadowLayer(1f, 0f, 1f, 0x66FFFFFF);// text shadow
        float radius = centerX/1.5f;//Center text inside pie slice fat end to pointed end - X
        int center = (int) (start+angle/2);//Center text inside pie slice fat end, top to bottom - Y
        int textX = (int)(radius * Math.cos(center * Math.PI / 180F)) + centerX;
        int textY = (int)(radius * Math.sin(center * Math.PI / 180F)) + centerY;
        start += angle;
        if(angle<30){continue;}//too small to print text on, so just skip it.
        canvas.drawText(String.valueOf(slices[i]), textX, textY, paint);
    }
    ImageView.setImageBitmap(bmp);
    TextView.setText(label);
}
}

还有一些可以显示的东西：

<?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>

现在它可以从如下主要活动调用：

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);