Question

我正在尝试在HorizontalScrollView父级内部实现自定义视图。自定义视图根据处理程序的时间重复绘制一条线到其Canvas。我想将自定义视图的可见宽度设置为1207px x 548px，但我希望该行能够超出可见范围并且我希望允许用户然后能够水平滚动以查看更多行。在我使用具有固定宽度和高度的框架布局围绕我的自定义视图类之前，这显然不允许任何滚动。现在，当我尝试使用下面的布局时，所有内容都显示为黑色（自定义视图上的背景为白色）。

我正在开发一款带有Honeycomb的华硕变压器。

这是我正在使用的布局的相关部分：

<HorizontalScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="548dp" >

    <maavapp.layout.CustomDraw
        android:id="@+id/custom_draw"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >
    </maavapp.layout.CustomDraw>
</HorizontalScrollView>

以下是必要时CustomDraw类的代码：

public class CustomDraw extends View {
private static int mSelected;
private ArrayList<Coordinate> measure1;
private ArrayList<Coordinate> measure2;
private ArrayList<Coordinate> measure3;
private boolean north = false, east = true, south = true, west = false;
private DrawHandler dh = new DrawHandler();
private boolean draw = true;
private int width;
private int height;
private int m2;

public CustomDraw(Context context) {
    super(context);
    init();

}

public CustomDraw(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
}

public CustomDraw(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    init();
}

public void init() {        
    measure1 = new ArrayList<Coordinate>();
    measure2 = new ArrayList<Coordinate>();
    measure3 = new ArrayList<Coordinate>();

    mSelected = Constants.MEASURE_1;
    width = 0;
    height = 0;
    m2 = 0;
}

public void setMeasure(int measure) {
    mSelected = measure;
}

public void toggleDraw() {
    draw = !draw;
    if(draw) {
        updateLine();
    }
}

public boolean isDrawing() {
    return draw;
}

public void updateLine() {
    // grab new coordinates for each measure
    /*new_coord(measure1);
    new_coord(measure2);
    new_coord(measure3);*/

    if(measure1.isEmpty() && measure2.isEmpty() && measure3.isEmpty()) {
        measure1.add(new Coordinate(0, 0));
        measure2.add(new Coordinate(0, 0));
        measure3.add(new Coordinate(0, 0));
    } else {
        Coordinate last_coord = measure1.get(measure1.size() - 1);

        measure2.add(new Coordinate(++m2, 25));

        if(last_coord.x >= width) {
            east = false;
            west = true;
        } else if(last_coord.x <= 0) {
            east = true;
            west = false;
        }

        if(last_coord.y >= height) {
            south = false;
            north = true;
        } else if(last_coord.y <= 0) {
            south = true;
            north = false;
        }

        Log.d("MAAV", "last_coord.x + 3: " + (last_coord.x + 3));
        Log.d("MAAV", "last_coord.y + 3: " + (last_coord.y + 3));

        if(south && east) {
            measure1.add(new Coordinate(last_coord.x + 3, last_coord.y + 3));
        } else if(south && west) {
            measure1.add(new Coordinate(last_coord.x - 3, last_coord.y + 3));
        } else if(north && east) {
            measure1.add(new Coordinate(last_coord.x + 3, last_coord.y - 3));
        } else if(north && west) {
            measure1.add(new Coordinate(last_coord.x - 3, last_coord.y - 3));
        }
    }

    if(draw) {
        dh.sleep(10);
    }
}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    this.width = w;
    this.height = h;
    super.onSizeChanged(w, h, oldw, oldh);
}

@Override
public void onDraw(Canvas c) {
    super.onDraw(c);
    Paint p = new Paint();
    p.setStyle(Paint.Style.FILL);

    p.setColor(Color.WHITE);
    c.drawPaint(p);
    p.setColor(Color.BLACK);

    switch(mSelected) {
    case Constants.MEASURE_1:
        for(int i = 0; i < measure1.size(); i++) {
            Coordinate coord = measure1.get(i);
            Log.d("MAAV", "drawing coord.x, coord.y: " + (coord.x) + ", " + (coord.y));
            c.drawRect(coord.x, coord.y, coord.x + 3, coord.y + 3, p);  
        }
        break;
    case Constants.MEASURE_2:
        for(int i = 0; i < measure2.size(); i++) {
            Coordinate coord = measure2.get(i);
            c.drawRect(coord.x, coord.y, coord.x + 3, coord.y + 3, p);
        }
        break;
    case Constants.MEASURE_3:
        for(int i = 0; i < measure2.size(); i++) {
            Coordinate coord = measure2.get(i);
            c.drawRect(coord.x, coord.y, coord.x + 3, coord.y + 3, p);
        }
        break;
    }

}

class DrawHandler extends Handler {

    @Override
    public void handleMessage(Message msg) {
        CustomDraw.this.updateLine();
        CustomDraw.this.invalidate();
    }

    public void sleep(long delayMillis) {
        this.removeMessages(0);
        sendMessageDelayed(obtainMessage(0), delayMillis);
    }
}

}

感谢您的帮助！

Answer 1

我认为您还必须设置视口： android：fillViewport =“true”

像：

<HorizontalScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true" >

具有自定义视图子项的水平滚动视图

1 个答案: