Android如何以编程方式创建滚动视图并将编程创建的视图添加到其中 [英] Android how to programmatically create scrollview and add programmatically created views into it

问题描述

好的，我正在尝试构建一个具有水平滚动视图的活动，用户可以在其中滚动浏览以查看不同的页面".我的思路是这些页面"将成为视图.以下是我的想法的模型(四处看看是否可行)

Alright I'm trying to build an activity that has a horizontal scrollview, that the user can swipe through, to view different "pages". My train of thought is these "pages" will be views. The following is a mockup of my idea (to mess around to see if it works)

我对此进行了如下尝试:

I've experimented with this as follows:

我的内容视图设置为滚动视图. (不确定这是否是错误的方法)

My content view is set to the the scrollview. (unsure if this is an incorrect approach)

我创建滚动视图，并按如下所示放置视图:

I create the scrollview, and place a view into it as follows:

private void setupScrollView()
{
    Display display = getWindowManager().getDefaultDisplay();
    DisplayMetrics outMetrics = new DisplayMetrics ();
    display.getMetrics(outMetrics);

    float density  = getResources().getDisplayMetrics().density;
    float dpHeight = outMetrics.heightPixels / density;
    float dpWidth  = outMetrics.widthPixels / density;

    int width = (int)MeasureUtils.convertDpToPixel(dpWidth, getApplicationContext());
    int height = (int)MeasureUtils.convertDpToPixel(dpHeight, getApplicationContext());

    _scrollView = new HorizontalScrollView(getApplicationContext());
    _scrollView.setBackgroundColor(Color.CYAN);
    _scrollView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

     Log.i("DEBUG", "Screen dp width = " + dpWidth + " screen dp height = " + dpHeight);

    TextView view = new TextView(getApplicationContext());
    view.setBackgroundColor(Color.RED);
    view.setText("TEST");

    view.setX(0); // Start at the left of the scrollview.

    view.setWidth(width); // Size it so that it fills to the right of the scrollview.

    TextView view2 = new TextView(getApplicationContext());
    view2.setBackgroundColor(Color.GREEN);
    view2.setText("TEST2");

    view2.setX(width); // Start the second "page/view" offscreen to the right where i can scroll to it

    view.setWidth(width); // Fill the screen width

    LinearLayout layout = new LinearLayout(getApplicationContext());
    layout.setBackgroundColor(Color.MAGENTA);

    layout.addView(view);

    layout.addView(view2);

    _scrollView.addView(layout);
}

上面的想法是，我将看到一个视图，它占据了屏幕，并代表了一个页面.此视图的颜色应为红色".然后，我可以水平向右滚动并查看代表下一页的第二个视图(view2).此视图的颜色应为绿色".这不会发生.我最终看到的是屏幕1，看起来是屏幕的1/3或1/2，线性布局几乎占据了整个屏幕(从屏幕右上角到CYAN的右边缘有一点缝隙)滚动视图出血).

The idea above is that I will see a view, that takes up the screen, representing a page. This view should be "RED" in color. I can then scroll horizontally to the right and see the second view (view2) representing the next page. This view should be "GREEN" in color. This does not happen. I end up seeing what looks like 1/3rd or 1/2 of my screen being view1, the linearlayout taking up almost the whole screen (a bit of a gap to the right edge where the CYAN from the scrollview bleeds through).

我以错误的方式来处理这个问题，和/或是否有可能按照我的方式来进行这项工作?

Am I approaching this the wrong way, and/or is it possible to make this work the way I'm going at it?

推荐答案

好的，我已经弄清楚了我做错了什么，结果却发现问题很小……

Alright I've figured out what I was doing wrong, and it turned out to be something very small...

完整的代码在这里:

    private void setupScrollView()
{
    Display display = getWindowManager().getDefaultDisplay();
    DisplayMetrics outMetrics = new DisplayMetrics ();
    display.getMetrics(outMetrics);

    float density  = getResources().getDisplayMetrics().density;
    float dpHeight = outMetrics.heightPixels / density;
    float dpWidth  = outMetrics.widthPixels / density;

    int width = (int)MeasureUtils.convertDpToPixel(dpWidth, getApplicationContext());
    int height = (int)MeasureUtils.convertDpToPixel(dpHeight, getApplicationContext());

    _scrollView = new HorizontalScrollView(getApplicationContext());
    _scrollView.setBackgroundColor(Color.CYAN);
    _scrollView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

    Log.i("DEBUG", "Screen dp width = " + dpWidth + " screen dp height = " + dpHeight);

    TextView view = new TextView(getApplicationContext());
    view.setBackgroundColor(Color.RED);
    view.setText("TEST");

    view.setX(0);

    view.setWidth(width);
    view.setHeight(height - 50);

    TextView view2 = new TextView(getApplicationContext());
    view2.setBackgroundColor(Color.GREEN);
    view2.setText("TEST2");

    view2.setX(0);

    view2.setWidth(width);
    view2.setHeight(height - 50);

    LinearLayout layout = new LinearLayout(getApplicationContext());
    layout.setBackgroundColor(Color.MAGENTA);

    layout.addView(view);

    layout.addView(view2);

    _scrollView.addView(layout);


}

这就像我以前那样以编程方式创建了水平滚动视图，但是问题是我将第二个视图设置为宽"，而应将其设置为"0"，如以下所示:

This creates a horizontal scrollview programmatically, as I had, but the problem was that I was setting the second view to be "width" away, when it should be set to "0"as can be seen by:

view2.setX(0);

有了这个，我得到2个视图"，它们类似于我可以滚动浏览的滚动视图中的页面.每个占整个页面.

With that, I get 2 "views" that resemble pages in my scrollview that I can swipe through. Each taking up the whole page.

讨厌关闭代码，这是我错过的一个简单解决方法:|

Hate having the code close and it being a simple fix that I missed :|

希望这对尝试这样做的其他人有所帮助.我将按照弗兰克的建议研究PageViewer.

Hope this helps anyone else that tries to do it this way. I'm going to look into the PageViewer as Frank suggested.

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