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我想要做的是将自定义视图添加到相对布局中。该相对布局是另一个线性布局的子布局。一切正常,除了自定义视图没有显示在它应该有的地方。

自定义查看代码:

public class DrawView extends View {

private Path path = new Path();
private Paint paint = new Paint();

public DrawView(Context context, AttributeSet attrs) {
    super(context, attrs);

    paint.setAntiAlias(true);
    paint.setStrokeWidth(2.2f);
    paint.setColor(Color.WHITE);
    paint.setStyle(Paint.Style.STROKE);
    paint.setStrokeJoin(Paint.Join.ROUND);


}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.drawPath(path, paint);

}

@Override
public boolean onTouchEvent(MotionEvent event) {
    float eX = event.getX();
    float eY = event.getY();

    switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
        path.moveTo(eX, eY);
        return true;
    case MotionEvent.ACTION_MOVE:
        path.lineTo(eX, eY);
        return true;
    case MotionEvent.ACTION_UP:
        break;
    default:
        return false;
    }
    invalidate();
    return true;
}

}

XML 布局(线性和相对):

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#F24738"
android:orientation="vertical" >
<RelativeLayout
    android:id="@+id/draw_container"
    android:layout_width="match_parent"
    android:layout_height="450dp"
    android:background="#FFFFFF">
</RelativeLayout>

这就是主要活动:

public class DrawActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_draw);

    final RelativeLayout parentLayout = (RelativeLayout) findViewById(R.id.draw_container);
    parentLayout.addView(new DrawView(this, null));
}

}

当我尝试:

setContentView(new DrawView(this, null));

一切正常。我被这里击中了。我知道,我错过了一些非常简单的东西。

4

1 回答 1

2

您的代码正在运行,但您在白色背景上绘制白色笔触。

尝试更改此行。-

paint.setColor(Color.WHITE);

为了

paint.setColor(Color.RED);

于 2013-04-07T19:08:19.570 回答