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如何在onDraw中绘制4行？这些是4条常量线，红色代表我的视图边框。我尝试绘图，只能绘制1行，甚至与我的屏幕宽度相同。

建议？

谢谢！

Answer 1

尝试：

public void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    Paint redPaint = new Paint();
    redPaint.setColor(Color.RED);
    redPaint.setStrokeWidth(5); // set stroke so you can actually see the lines

    canvas.drawLine(0, 0, getMeasuredWidth(), 0, redPaint);
    canvas.drawLine(getMeasuredWidth(), 0, getMeasuredWidth(), getMeasuredHeight(), redPaint);
    canvas.drawLine(getMeasuredWidth(), getMeasuredHeight(), 0, getMeasuredHeight(), redPaint);
    canvas.drawLine(0, getMeasuredHeight(), 0, 0, redPaint);
}

Answer 2

void    drawLine(float startX, float startY, float stopX, float stopY, Paint paint)
Draw a line segment with the specified start and stop x,y coordinates, using the specified paint.

＃

Paint paint = new Paint();
paint.setColor(Color.Red);

onDraw( Canvas canvas){
     canvas.drawLine(x,y,x1,y1, paint);
     canvas.drawLine(x,y,x1,y1, paint);
     canvas.drawLine(x,y,x1,y1, paint);
     canvas.drawLine(x,y,x1,y1, paint);
}

更改（x，y）和（x1，y1）

的值

如何在onDraw中绘制4行？ - android

2 个答案: