Android：Canvas.drawText按鈕點擊時

Question

如何按drawText點擊按鈕？如何在按鈕單擊時看到按鈕並繪製文本？我無法做到，下面是我繪製文本的代碼。

public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    drawView = new DrawView(this); 
    setContentView(drawView); 
} 
public DrawView(Context context) { 
    super(context); 
    textpaint.setColor(Color.WHITE); 
} 
public void onDraw(Canvas canvas) { 
    canvas.drawText("Testing", 20, 55, textpaint); 
}

Answer 1

DrawView繼承了什麼？ 爲什麼不使用一個簡單的XML佈局在其中放置一個TextView和使用setVisible您OnClickListener

示例代碼中：

public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.my_view); 
    Button myButton = (Button) findViewById(R.id.my_button); 
    final MySurfaceView surfaceView = (MySurfaceView) findViewById(R.id.mysurface); 
    myButton.setOnClickListener(new OnClickListener() { 
     @Override 
     public boolean onClick(View v) { 
      // here you should change the position and the text you want to write 
      // like surfaceView.setCoordinates(x, y); 
      // and surfaceView.setTextToDraw("myText"); 
      return true; 
     } 
    }); 
} 

您需要創建自己的課程SurfaceView。如何做到這一點作爲一個例子：http://www.droidnova.com/playing-with-graphics-in-android-part-ii,160.html

XML：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"> 
    <org.mypackage.MySurfaceView android:id="@+id/mysurface" 
     android:layout_width="300dp" 
     android:layout_height="300dp" /> 
    <Button android:id="@+id/my_button" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Push it real good!" /> 
</LinearLayout>