动态添加和删除映射按钮到 TableLayout

Question

I'm struggling to find a good way of adding and removing clickable buttons in a TableLayout.

So I currently have a HashMap that contains an integer and an object. It updates as the user needs it too. When the user presses the "add project" button, I would like it to go through the motions of adding a project to the HashMap and then update my TableLayout.

I'd like to limit each row to 2 buttons. I noticed that before I can update the TableLayout (or any layout) with the new project added in, I have to remove the previous iteration.

I've tried numerous different ways to add and remove the buttons in a row but none of them seem to have worked.

One example of what I did is:

int i = mProjectMap.size();
for(Map.Entry<Integer, Counter> entry : mProjectMap.entrySet()) { // This already has one entry before reaching this loop
    if(i % 2 == 0 || mLayoutProjects.getChildCount() == 0) {
        mTableRow = new TableRow(mMainContext);
        mLayoutProjects.addView(mTableRow);
    }

    mTableRow.addView(entry.getValue());
};

As for removing the views I've tried:
mLayoutProjects.removeAllViews();

and:
mLayoutProjects.removeViewsInLayout();

And many more.

What should happen is as follows:

1) User clicks "Add Project" button. 2) Project is populated with relevant information. (done) 3) Project is added to mProjectMap (done) 4) mLayoutProjects has all containing views removed. 5) if mLayoutProjects.getChildCount() equals 0 OR i % 2 equals 0 then: Create new row and add it to mLayoutProjects. 6) Add a project button to the row.

Instead, When I press the "Add Project" button, that loop seems to add everything on the first iteration, but nothing shows on the screen in terms of buttons (I have a project counter which increments once). I then press the button again and the app crashes.

Answer 1

Update:

I have fixed the issue with a different way. For those who stumble on this I shall include the solution for completeness:

So I changed everything to a LinearLayout and in the "addProjectButton" function I had the following:

int i = mProjectMap.size();
for(Map.Entry<Integer, Counter> entry : mProjectMap.entrySet()) {
    if((entry.getKey() - 1) % 2 == 0 || mLayoutRow == null) {
        mLayoutRow = new LinearLayout(mMainContext);
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
            LinearLayout.LayoutParams.MATCH_PARENT,
            LinearLayout.LayoutParams.WRAP_CONTENT
        );
        mLayoutRow.setOrientation(LinearLayout.HORIZONTAL);
        mLayoutRow.setGravity(Gravity.CENTER);
        mLayoutRow.setLayoutParams(lp);
        mLayoutProjects.addView(mLayoutRow);
    }

    mLayoutRow.addView(entry.getValue());
}

Then, in my "removeProjectButton" function:

for(Map.Entry<Integer, Counter> entry : mProjectMap.entrySet()) {
    if(entry.getValue().getParent() != null) {
        ((ViewGroup) entry.getValue().getParent().removeView(entry.getValue());
    }
}

mLayoutRow = null;

This seems to run perfectly fine without any problems... Though it could end up being too good to be true but only time will tell.