Android开发：如何实现未点击Copy前禁止Share并提示用户？

Got it, let's tweak your code to implement the exact behavior you want—disabling the Share option until the user taps Copy, and showing a toast if they try to share before copying. Here's the revised code with all the necessary changes:

// Add this instance variable at the top of your Activity/Fragment
private boolean isTextCopied = false;

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    if (id == R.id.share) {
        // Check if text has been copied first
        if (!isTextCopied) {
            Toast.makeText(getApplicationContext(), getString(R.string.please_copy_first), Toast.LENGTH_SHORT).show();
            return true; // Consume the click so super doesn't handle it
        }
        // Proceed with sharing if text is copied
        Intent sharingIntent = new Intent(android.content.Intent.ACTION_SEND);
        sharingIntent.setType("text/plain");
        String shareBody = returnedText.getText().toString();
        String shareSub = "";
        sharingIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, shareSub);
        sharingIntent.putExtra(android.content.Intent.EXTRA_TEXT, shareBody);
        startActivity(Intent.createChooser(sharingIntent, "Share using"));
        Toast.makeText(getApplicationContext(), getString(R.string.send_text), Toast.LENGTH_SHORT).show();
        return true;
    } else if (id == R.id.copy) {
        // Copy text to clipboard
        ClipboardManager clipboard = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);
        clipboard.setText(returnedText.getText());
        Toast.makeText(getApplicationContext(), getString(R.string.copy_text), Toast.LENGTH_SHORT).show();
        // Mark text as copied and refresh the menu to enable Share
        isTextCopied = true;
        invalidateOptionsMenu(); // This triggers onPrepareOptionsMenu
        return true;
    }
    return super.onOptionsItemSelected(item);
}

// Override this method to dynamically enable/disable the Share menu item
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    MenuItem shareItem = menu.findItem(R.id.share);
    // Disable Share if text hasn't been copied yet
    shareItem.setEnabled(isTextCopied);
    return super.onPrepareOptionsMenu(menu);
}

Let me break down the key changes to make this work:

• State tracking variable: The isTextCopied boolean keeps tabs on whether the user has copied the text. We start it as false since no copy action has happened initially.
• Dynamic menu state: The onPrepareOptionsMenu method runs every time the menu is about to show. We use this to toggle the Share item's enabled status—users will see Share grayed out until they tap Copy, which gives clear visual feedback.
• Copy action handling: When the user taps Copy, we flip isTextCopied to true and call invalidateOptionsMenu() to refresh the menu right away, so Share becomes usable immediately after copying.
• Share action guard: When Share is tapped, we first check if isTextCopied is true. If not, we show a toast asking the user to copy first and exit early. If it is true, we proceed with the normal sharing flow.
• Cleaned up logic: I merged your two separate switch statements into a single if-else if chain for better readability—no need to check the item ID twice!

Don't forget to add the new string resource (like R.string.please_copy_first) to your strings.xml file so the warning toast message is properly localized.

内容的提问来源于stack exchange，提问作者Cule