当添加的onCreate我的自定义视图只得到画 [英] my Custom View gets drawn only when added in onCreate

问题描述

我做了一个GraphBar自定义视图是一个 RelativeLayout的与的TextView 在底部，一个的ImageView ，不同的高度，上面。这里是code：

I made a "GraphBar" custom view that is a RelativeLayout with a TextView on the bottom and an ImageView, varying in height, above that. Here is the code:

public class GraphBar extends RelativeLayout {

    private int mAvailHeight; // space for the bar (component minus label)
    private float mBarHeight; // 0.0-1.0 value

    public GraphBar(Context context) {
        this(context, null);
    }

    public GraphBar(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public GraphBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        LayoutInflater.from(context).inflate(R.layout.graphbar, this, true);
        setId(R.id.graphBar); // defined in <merge> but not assigned (?)
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        mAvailHeight = getHeight()-findViewById(R.id.label).getHeight();
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);

        View bar2 = findViewById(R.id.smallBar);
        RelativeLayout.LayoutParams llp2 = (RelativeLayout.LayoutParams) bar2.getLayoutParams();
        llp2.height = Math.round((float)mAvailHeight * mBarHeight);
    }

    public void setBarHeight(float value, float max) {
        mBarHeight = value / max;
        findViewById(R.id.smallBar).requestLayout();
    }

    public void setLabel(CharSequence c) {
        ((TextView) findViewById(R.id.label)).setText(c);
    }
}

在添加这些GraphBars和设置在的onCreate自己的身高（）效果很好，如果我创建他们onClickSomething或再次调用 setBarHeight（）上创建的酒吧，看到变化的唯一途径是加载视图层次。有人告诉我这里，这意味着我需要调用的地方 requestLayout（）。还有什么地方比修改后的 mBarHeight ？任何帮助吗？我想无处不在，并与无效（）了。

While adding these GraphBars and setting their height in onCreate() works well, if I create them onClickSomething or call again setBarHeight() on the created bars, the only way to see changes is Load View Hierarchy. I've been told here that it means I need to call somewhere requestLayout(). Where else than after modifying mBarHeight? Any help? I tried everywhere, and with invalidate() too.

感谢您， 安德烈

（如果你需要我可以张贴活动与我做我的测试和graphbar.xml）

(if you need I can post the activity with which i do my tests and the graphbar.xml)

我发现它可能错误。解决方法应该是，再次呼吁 requestLayout（）。我还是不明白的地方我可以把通话。

I've found it's probably a bug. The workaround should be, again, calling requestLayout(). Still i don't understand where i can put the call.

推荐答案

我终于找到了一种方法再次调用 requestLayout（）。我叫 setWillNotDraw（假）的构造函数，以便在的OnDraw（）（即在 onLayout（））我可以调用额外的 requestLayout（）。这会产生一个愚蠢的周期，但在美学解决了这个问题。

I've finally found a way to call again requestLayout(). I called setWillNotDraw(false) in the constructor so that in onDraw() (that is after onLayout()) I can call the extra requestLayout(). This generates a stupid cycle but solves the problem aesthetically.

如果有人知道一个更好的解决方案，让我知道... 在这里新的code（修改毗邻评论）：

If anyone knows a better solution, let me know... here the new code (modifies are next to comments):

//...
    public GraphBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        LayoutInflater.from(context).inflate(R.layout.graphbar, this, true);
        setWillNotDraw(false); // WORKAROUND: onDraw will be used to make the
                                // redundant requestLayout() call
        setId(R.id.graphBar);
    }
//...
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        // i think it's one of the worst workaround one could think of.
        // luckily android is smart enough to stop the cycle...
        findViewById(R.id.smallBar).requestLayout();
    }

    public void setBarHeight(float value, float max) {
        mBarHeight = value / max;
        View bar =   findViewById(R.id.smallBar);

        bar.requestLayout(); // because when we create this view onDraw is called...
        bar.invalidate();    // ...but not when we modify it!!!
                            //so we need to invalidate too
    }
//...

这篇关于当添加的onCreate我的自定义视图只得到画的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！