Android - 如何让我的按钮更改画布上的图形

Question

我的代码如下。

我不明白的是如何使用按钮来改变我正在绘制的图形。我有点想能够调用像重绘图的方法，但我不明白我该怎么做。

干杯

菲尔

package com.android.phil.smartphonecharts; 

import android.app.Activity; 
import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Paint.Style; 
import android.os.Bundle; 
import android.view.Display; 
import android.view.View; 
import android.widget.ImageButton; 
import android.widget.RelativeLayout; 

public class GraphActivity extends Activity 
{ 
    int[][] graphData = {{591566,601708,591566,600509}, 
       {593573,594182,586592,591489}, 
       {600088,602233,596358,599401}, 
       {592071,601150,592071,600120}, 
       {592292,593668,586095,591998}, 
       {599672,599672,591552,592353}, 
       {601442,602856,592655,599676}, 
       {606747,610577,601314,601480}, 
       {609190,609678,604883,608299}, 
       {609659,610142,606671,608738}, 
       {604655,609576,604238,608527}, 
       {605158,607207,602377,603708}, 
       {607479,609148,604210,606009}, 
       {600472,607140,597344,606290}, 
       {603668,604520,598648,602001}, 
       {606743,608430,604950,605229}, 
       {604232,609133,603288,609133}, 
       {600916,605409,599716,605103}, 
       {600264,602341,598683,599738}, 
       {598570,599359,595182,598334}, 
       {597654,602046,597271,600007}, 
       {592071,601150,592071,600120}, 
       }; 

    int highest = 0; 
    int lowest = 0; 
    int multiY = 10; 
    int multiX = 21; 
    int graphToggle = 0; 
    int numbPeriods = 22; 

    float previous = 0; 
    float current = 0; 
    float stepX = 0; 
    float stepY = 0; 
    float stepPercent = 0; 
    float topLeftX = 0; 
    float topLeftY = 0; 
    float bottomRightX = 0; 
    float bottomRightY = 0; 
    float graphHeight = 0; 
    float graphWidth = 0; 
    double graphLow = 0; 
    double graphHigh = 0; 
    double graphRange = 0; 
    double n = 0; 
    double m = 0; 

    public int graph_toggle = 0; 
    public int data_toggle=0; 

    public float width; 
    public float height; 

    @Override 
    public void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.graph_layout); 

     Display display = getWindowManager().getDefaultDisplay(); 
     width = display.getWidth(); 
     height = display.getHeight(); 

     final ImageButton graph_toggle_button = (ImageButton) findViewById(R.id.graph_toggle); 
     final ImageButton graph_settings_button = (ImageButton) findViewById(R.id.graph_type); 
     final ImageButton data_toggle_button = (ImageButton) findViewById(R.id.data_toggle); 
     final ImageButton moving_averages_button = (ImageButton)findViewById(R.id.moving_averages); 

     //Define the view into which our canvas will be drawn. 
     int graph_display_height = (int)(height*0.75); 
     int graph_display_width = (int)width; 
     CustomDrawableView mCustomDrawableView = new CustomDrawableView(this); 

     RelativeLayout graphLayout = (RelativeLayout)findViewById(R.id.graph_window); 

     RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(graph_display_width,graph_display_height); 
     lp.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM); 

     mCustomDrawableView.setLayoutParams(lp); 
     graphLayout.addView(mCustomDrawableView); 

     graph_toggle_button.setOnClickListener(new View.OnClickListener() 
     { 
      public void onClick(View arg0) 
      { 
       if (graph_toggle==2) 
       { 
        graph_toggle=0; 
       } 
       else 
       { 
        graph_toggle++; 
       } 

       if (graph_toggle==0) 
       { 
        graph_settings_button.setImageResource(R.drawable.close); 
       } 
       if (graph_toggle==1) 
       { 
        graph_settings_button.setImageResource(R.drawable.ohlc_bars); 
       } 
       if(graph_toggle==2) 
       { 
        graph_settings_button.setImageResource(R.drawable.candles); 
       }    
      }   
     }); 
     data_toggle_button.setOnClickListener(new View.OnClickListener() 
     { 
      public void onClick(View arg0) 
      { 
       if (data_toggle==2) 
       { 
        data_toggle=0; 
       } 
       else 
       { 
        data_toggle++; 
       } 

       if (data_toggle==0) 
       { 
        data_toggle_button.setImageResource(R.drawable.ohlc_bars_daily); 
       } 
       if (data_toggle==1) 
      { 
        data_toggle_button.setImageResource(R.drawable.ohlc_bars_weekly); 
       } 
       if(data_toggle==2) 
       { 
        data_toggle_button.setImageResource(R.drawable.ohlc_bars_monthly); 
       }    
      }   
     });   
    }  
    public class CustomDrawableView extends View 
    { 
     public CustomDrawableView(Context context) 
     { 
      super(context); 
     } 
     @Override 
     protected void onDraw(Canvas canvas) 
     { 
      invalidate(); 
      super.onDraw(canvas); 

      // custom drawing code here 
      // remember: y increases from top to bottom 
      // x increases from left to right 

      Paint paint = new Paint(); 
      paint.setStyle(Paint.Style.FILL); 

      // make the entire canvas white 
      paint.setColor(Color.TRANSPARENT); 
      canvas.drawPaint(paint); 

      //Set co-ordinates of display window using half the heigh of the screen and 
      //indent the window by 5% 
      topLeftX = (float)0; 
      topLeftY = (float)(height*0.01); 

      bottomRightX = (float)(width*0.80); 
      bottomRightY = (float)(height*0.45); 

      //Width and height of the window are defined by the X and Y co-ords calculated above. 
      graphWidth = bottomRightX-topLeftX; 
      graphHeight = bottomRightY-topLeftY; 

      //Calculate the HighestHigh and LowestLow of the data set. 
      highest = mHighestHigh(graphData,graphToggle); 
      lowest = mLowestLow(graphData,graphToggle); 

      //Total graph range that we want to display based on the values in data 

      //Calculate the Lowest value from the data set drawn on the graph 
      graphLow = lowest*0.99; 

      //Calculate the highest value from the data set drawn on the graph 
      graphHigh = highest*1.01; 
      //is equal to the highest value minus lowest value +/-5% 
      graphRange = graphHigh-graphLow; 

      //stepX = space between vertical bars 
      stepX = graphWidth/multiX; 
      //stepY = space between horizontal bars 
      stepY = graphHeight/multiY; 
      //step = 1 hundredth of the total height of the box. 
      stepPercent = (graphHeight)/100; 

      //draw the outline box 
      paint.setStyle(Style.STROKE); 
      paint.setColor(Color.WHITE); 
      canvas.drawRect(topLeftX, topLeftY, bottomRightX, bottomRightY, paint); 

      //draw horizontal lines 
      paint.setColor(Color.WHITE); 
      paint.setTextSize(10); 

      canvas.drawText(mD2S2DP(graphLow/100), (float)(width*0.81), bottomRightY+5, paint); 
      for (int i = 1; i < multiY; i++) 
      {//canvas.drawLine(startX, startY, stopX, stopY, paint) 
       paint.setColor(Color.rgb(255,0,0)); 
       canvas.drawLine(topLeftX, topLeftY+(stepY*i), bottomRightX, topLeftY+(stepY*i), paint); 
       paint.setColor(Color.WHITE);    
       paint.setTextSize(10); 
       canvas.drawText("Hello Android!", (float)(width*0.81), topLeftY+(stepY*i)+5,paint); 
      } 
      paint.setColor(Color.WHITE); 
      paint.setTextSize(10); 
      canvas.drawText(mD2S2DP(graphHigh/100), (float)(width*0.81), topLeftY+5, paint); 


      //draw vertical lines and diagonal random price lines 
      for (int i = 1; i < multiX; i++) 
      {//canvas.drawLine(startX, startY, stopX, stopY, paint) 
       paint.setColor(Color.rgb(255,255,255)); 
       paint.setStrokeWidth(1); 
       canvas.drawLine(topLeftX+(stepX*i), topLeftY, topLeftX+(stepX*i), bottomRightY, paint); 
      } 

      //Inverts the data set and draws it at the appropriate 
      n = (topLeftY-bottomRightY)/graphRange; 
      m = bottomRightY-(n*graphLow); 

      //draw close line graph 
      for (int i = 1; i < (multiX+1); i++) 
      { 
       //DashPathEffect dashPath = new DashPathEffect(new float[]{10,10}, 1); 
       //paint.setPathEffect(dashPath); 
       previous = (float)(n*graphData[i-1][3]+m); 
       current = (float)(n*graphData[i][3]+m); 

       if(previous>current) 
       { 
        paint.setColor(Color.rgb(255,0,0)); 
        paint.setStrokeWidth(2); 
       } 
       else 
       { 
        paint.setColor(Color.rgb(0,255,0)); 
        paint.setStrokeWidth(2); 
       } 
       //canvas.drawLine(startX, startY, stopX, stopY, paint) 

       canvas.drawLine(topLeftX+(stepX*(i-1)),previous, topLeftX+(stepX*i), current, paint); 
      } 
     } 
    } 

    public int mHighestHigh(int[][]data, int graphToggle) 
    {//method to calculate the highest high of the data set; 
     int highValue = graphToggle==0?data[0][3]:data[0][1]; 
     for (int i=1; i<data.length; i++) 
     { 
      if ((graphToggle==0?data[i][3]:data[i][1]) > highValue) 
      { 
       highValue = graphToggle==0?data[i][3]:data[i][1]; //new maximum 
      } 
     } 
     System.out.println("highValue="+highValue); 
     return highValue; 
    } 

    public int mLowestLow(int[][]data,int graphToggle) 
    {//method to calculate the lowest low of the data set; 
     int lowValue = graphToggle==0?data[0][3]:data[0][2]; 
     for (int i=1; i<data.length; i++) 
     { 
      if ((graphToggle==0?data[i][3]:data[i][2]) < lowValue) 
      { 
       lowValue = graphToggle==0?data[i][3]:data[i][2]; //new minimum 
      } 
     } 
     System.out.println("lowValue=:"+lowValue); 
     return lowValue; 
    } 
    public String mD2S2DP(double doubleValue) 
    {//method to turn a double to a string and return it to two dp 

     //Convert the double to a string. 
     String tempString = Double.toString(doubleValue); 
     //Find the location of the decimal point in the string. 
     int index = tempString.indexOf('.'); 
     //remove anything from the string after 2 characters after the decimal point. 
     String returnString = tempString.substring(0, index+3); 
     //return the result. 
     return returnString; 
    } 
} 

Answer 1

的方法是invalidate()，它的时间表在主线程循环调用它的视图的重绘。事实上，你不应该在你的自定义视图的onDraw()中调用它（除非你需要重复重画，以执行一些类似框架的动画）。

通常会改变影响方面的某些方法（例如ImageView.setImageDrawable()），同时还会打电话给invalidate()。因此，您可以添加一个方法，如CustomDrawableView.setGraphData(data)执行更改，然后调用invalidate()。

当然，您也可以从您的按钮内部调用mCustomDrawableView.invalidate()单击侦听器代码。

请注意，如果更改还涉及视图父级中的大小或位置，您还可以致电requestLayout()。