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我在我的窗口小部件中重新制作畫布時遇到問題。我創建自定義小部件,並且想要在點擊時重新繪製第一個單元格。 有INS活動無法刷新畫布 - 通過畫圖但不會更改
public class TestView extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ElementView ev = (ElementView)findViewById(R.id.surface2);
ev.setOnClickListener(evOnClick);
}
public OnClickListener evOnClick = new OnClickListener() {
@Override
public void onClick(View v) {
ElementView temp=(ElementView)v;
temp.paint.setColor(Color.RED);
temp.canvas.drawRect(new Rect(0,0,90,90),temp.paint);
temp.postInvalidate();
}
};
}
且有ElementView(窗口小部件,我要重繪)
public class ElementView extends View {
private final int width=100;
private final int height=100;
public Paint paint=null;
public Canvas canvas=null;
public ElementView(Context context) {
super(context);
paint = new Paint();
}
public ElementView(Context context, AttributeSet attr) {
super(context, attr);
paint = new Paint();
}
public ElementView(Context context, AttributeSet attr, int defaultStyles) {
super(context, attr, defaultStyles);
paint = new Paint();
}
@Override
protected void onMeasure(int widthSpec, int heightSpec) {
int measuredWidth = MeasureSpec.getSize(widthSpec);
int measuredHeight = MeasureSpec.getSize(heightSpec);
setMeasuredDimension(this.width,this.height);
}
@Override
protected void onDraw(Canvas canvas) {
this.canvas=canvas;
// get the size of your control based on last call to onMeasure
int height = getMeasuredHeight();
int width = getMeasuredWidth();
// Now create a paint brush to draw your widget
paint.setColor(Color.GREEN);
//define border
this.canvas.drawLine(0, 0, 0, 99, paint);
this.canvas.drawLine(0, 0, 99,0, paint);
this.canvas.drawLine(99, 0, 99, 99, paint);
this.canvas.drawLine(0, 99, 99,99, paint);
//define cells
this.canvas.drawLine(0,50,99,50,paint);
this.canvas.drawLine(30,0,30,50,paint);
//draw green rectangle
this.canvas.drawRect(new Rect(0,0,50,50),paint);
//draw some text
paint.setTextSize(8);
paint.setColor(Color.RED);
String displayText = "test";
Float textWidth = paint.measureText(displayText);
int px = width/2;
int py = height/2;
this.canvas.drawText(displayText, px - textWidth/2, py, paint);
}
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
paint.setColor(Color.RED);
//change color of first cell
canvas.drawRect(new Rect(0,0,50,50),paint);
return super.dispatchTouchEvent(event);
}
}
當我點擊ElementView它在的onClick活動進入並通過代碼沒有錯誤或異常,但不會改變視圖。有人可以告訴我哪裏錯了嗎?
如果你有答案..如果它工作,請在你的問題部分添加這段代碼作爲「編輯」...以便其他人也可以學習 – rahul 2011-05-18 11:22:01