Canvas Änderungspfad

Question

Ich habe einen Spinner in meinem Layout. Ich möchte die Form ändern, die als ein Pfad gezeichnet wird, wenn ein anderer Artikel ausgewählt wird. Derzeit fügt mein Code meinen zweiten Pfad zu dem ersten hinzu, anstatt ihn einfach zu ersetzen. Hier ist mein Code:

import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Path; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.View; 
import android.view.Window; 
import android.view.WindowManager; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.LinearLayout; 
import android.widget.Spinner; 

import java.util.ArrayList; 
import java.util.List; 
import java.util.Random; 

public class MainActivity extends AppCompatActivity { 
    private MyView myView; 
    private boolean firstTimeThru = true; 
    private LinearLayout root; 
    private Spinner mySpinner; 
    private Paint myPaint; 
    private Path path = new Path(); 

    float[] finalXCoord, finalYCoord; 
    float[] xCoord1 = {0,30, 50}; 
    float[] yCoord1 = {0, 100, 40}; 

    float[] xCoord2 = {52,300, 100, 60}; 
    float[] yCoord2 = {100, 200, 40, 80}; 


    @Override 


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

     finalXCoord = xCoord1; 
     finalYCoord = yCoord1; 
     // Hide the Title Bar 
     requestWindowFeature(Window.FEATURE_NO_TITLE); 

     // Hide the Status Bar 
     getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); 

     root = new LinearLayout(this); 
     root.setOrientation(LinearLayout.VERTICAL); 

     // Create the spinner, add contents, add events, add to Layout 
     mySpinner = new Spinner(this); 

     List<String> list = new ArrayList<String>(); 
     list.add("1st Path"); 
     list.add("2nd Path"); 

     ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, list); 
     mySpinner.setAdapter(spinnerArrayAdapter); 

     myPaint = new Paint(); 
     myPaint.setColor(Color.GREEN); 

     mySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { 
      @Override 
      public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) { 
       System.out.println(mySpinner.getSelectedItemId()); 
       if (mySpinner.getSelectedItemId()==0) { 
        myPaint.setColor(Color.GREEN); 
        finalXCoord = xCoord1; 
        finalYCoord = yCoord1; 

       } 
       if (mySpinner.getSelectedItemId()==1) { 
        myPaint.setColor(Color.RED); 
        finalXCoord = xCoord2; 
        finalYCoord = yCoord2; 
       } 
       if (!firstTimeThru) { 
        System.out.println("Not First Time"); 
        //demoview.changeToRed(); 
       } 
       System.out.println(myPaint.getColor()); 
      } 
      @Override 
      public void onNothingSelected(AdapterView<?> parentView) { 
       // your code here 
      } 
     }); 

     root.addView(mySpinner); 

     // Add view with canvas 
     myView = new MyView(this); 
     root.addView(myView); 

     setContentView(root); 

    } 

    public class MyView extends View { 

     public Canvas mCanvas; 

     public MyView(Context context) { 
      super(context); 
     } 

     public void drawPath(float[] xCoord, float[] yCoord) { 
      path.moveTo(xCoord[0], yCoord[0]); 
      for(int i=1; i<xCoord.length; i++) { 
       path.lineTo(xCoord[i], yCoord[i]); 
      } 
      path.close(); 
      mCanvas.drawPath(path, myPaint); 
      invalidate(); 
     } 

     protected void onDraw(Canvas canvas) { 
      mCanvas = canvas; 

      //myPaint.setStyle(Paint.Style.FILL_AND_STROKE); 
      myPaint.setStrokeWidth(10); 
      myPaint.setPathEffect(null); 
      //paint.setColor(Color.BLACK); 
      myPaint.setStyle(Paint.Style.STROKE); 

      drawPath(finalXCoord, finalYCoord); 
      //invalidate(); 

     } 
    } 
} 

Answer 1

Sie müssen wahrscheinlich Ihren Weg zurück:

public void drawPath(float[] xCoord, float[] yCoord) { 

    path.reset(); 

    path.moveTo(xCoord[0], yCoord[0]); 
    for(int i=1; i<xCoord.length; i++) { 
     path.lineTo(xCoord[i], yCoord[i]); 
    } 
    path.close(); 
    mCanvas.drawPath(path, myPaint); 
    invalidate(); 
}