Question

我是Android开发的新手，我正在尝试学习如何以编程方式将工具栏添加到相对视图中。本质上，我试图在代码中执行Blank项目模板，而不是使用基于XML的方法。我的应用程序将启动，但我看到的是我添加的TextView，并没有看到工具栏或菜单膨胀并放置在屏幕顶部的工具栏上。这是我到目前为止的代码：

    public class MainActivity extends AppCompatActivity {
    private RelativeLayout relativeLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Create the relative layout programmatically
        createRelativeLayout();

        // Set the content view with the instantiated relative layout
        setContentView(this.relativeLayout);

        // Create and add the action bar
        setSupportActionBar(createToolbar());

        // Create a text view and add it
        this.relativeLayout.addView(createTextView());
    }

    private void createRelativeLayout() {
        relativeLayout = new RelativeLayout(this);

        // Specifies the layout properties
        RelativeLayout.LayoutParams relativeParams = new RelativeLayout.LayoutParams(
                RelativeLayout.LayoutParams.MATCH_PARENT,
                RelativeLayout.LayoutParams.MATCH_PARENT
        );
        relativeLayout.setLayoutParams(relativeParams);
    }

    private TextView createTextView() {
        TextView textView = new TextView(this);

        // Set initial layout parameters
        RelativeLayout.LayoutParams textViewParams = new RelativeLayout.LayoutParams(
                RelativeLayout.LayoutParams.WRAP_CONTENT,
                RelativeLayout.LayoutParams.WRAP_CONTENT
        );

        // Set alignment parameters
        textViewParams.addRule(RelativeLayout.ALIGN_PARENT_TOP);
        textViewParams.addRule(RelativeLayout.CENTER_HORIZONTAL);

        textViewParams.setMargins(0, 82, 0, 0);
        textView.setText(R.string.app_name);

        textView.setLayoutParams(textViewParams);

        return textView;
    }

    private Toolbar createToolbar() {
        Toolbar toolbar = new Toolbar(this);
        Toolbar.LayoutParams toolBarParams = new Toolbar.LayoutParams(
                Toolbar.LayoutParams.MATCH_PARENT,
                R.attr.actionBarSize
        );
        toolbar.setLayoutParams(toolBarParams);
        toolbar.setBackgroundColor(Color.BLUE);
        toolbar.setPopupTheme(R.style.AppTheme_PopupOverlay);
        toolbar.setVisibility(View.VISIBLE);
        return toolbar;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

非常感谢任何帮助，谢谢。

Answer 1

简短回答：将视图添加到RelativeLayout.LayoutParams 时应使用RelativeLayout

您已将Toolbar.LayoutParams作为布局参数分配给工具栏，除非您将RelativeLayout.LayoutParams指定给工具栏，否则它将无效。

在android视图通胀中，每个子视图的布局参数应根据其父视图设置。如果您的工具栏例如在LinearLayout中，您应该使用'LinearLayout.LayoutParams'作为工具栏的布局参数。

以编程方式将工具栏添加到Android中的RelativeView

1 个答案: