Question

我是Android Studio的新手，作为一个学习练习，我试图创建一个应用程序，而不使用除manifest之外的任何xml文件。我想在Java中完全创建活动，布局，工具栏和抽屉菜单。我知道这不是通常的事情，我可能会给自己带来很多不必要的压力，但正如我所说，这是一个学习练习。一切似乎都在执行，但工具栏不显示。此外，getSupportActionBar（）。getHeight（）返回零。

感谢任何帮助！

谢谢，约翰

这是我的Activity.java

package com.example.john.myblankapplication;

import android.graphics.Color;
import android.os.Bundle;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.support.design.widget.Snackbar;

import android.view.Gravity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;

/**
 * Created by John on 7/3/2016.
 */

public class MyActivity extends AppCompatActivity {
    private RelativeLayout myRelativeLayout;
    private LinearLayout myLinearLayout;
    private Toolbar myToolbar;
    private TextView myTextView;
    private ActionBar myActionBar;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Create the main layout programmatically
        createRelativeLayout();
        createLinearLayout();

        // I have tried it with LinearLayout and RelativeLayout
        setContentView(myLinearLayout);

        // Create the toolbar layout programmatically
        createToolbarLayout();

        //myLinearLayout.addView(myToolbar); // that turned the whole screen red

        setSupportActionBar(myToolbar);
        myActionBar = getSupportActionBar();
        myActionBar.setDisplayHomeAsUpEnabled(true); // new test - didn't help

        // Create the text programmatically
        myLinearLayout.addView(createTextView());

        Snackbar.make(myTextView, "ActionBarHeight="+myActionBar.getHeight(),
                Snackbar.LENGTH_LONG)
                .setAction("Action", null).show(); // displays 0
    }

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

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

    private void createLinearLayout() {
        myLinearLayout = new LinearLayout(this);

        // Specifies the layout properties
        LinearLayout.LayoutParams linearParams = new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.MATCH_PARENT,
                LinearLayout.LayoutParams.MATCH_PARENT
        );
        myLinearLayout.setLayoutParams(linearParams);
    }

    private Toolbar createToolbarLayout() {
        myToolbar = new Toolbar(this);
        Toolbar.LayoutParams toolBarParams = new Toolbar.LayoutParams(
                RelativeLayout.LayoutParams.MATCH_PARENT,
                R.attr.actionBarSize, Gravity.TOP
        );
        myToolbar.setTitle("My Toolbar");
        myToolbar.setLayoutParams(toolBarParams);
        myToolbar.setBackgroundColor(Color.RED);
        myToolbar.setVisibility(View.VISIBLE);
        return myToolbar;
    }

    private TextView createTextView() {
        myTextView = 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);

        myTextView.setText("Here is some text");

        myTextView.setLayoutParams(textViewParams);

        return myTextView;
    }

}

Answer 1

我建议将工具栏设为自定义视图，并在布局屏幕中设置尺寸。如果导入工具栏包，则可以将自定义视图声明为工具栏。然后，您可以使用内置的所有工具栏命令来添加标题和项目。

希望这有帮助！

Answer 2

您还需要将工具栏添加到线性布局。

     // Create the toolbar layout programmatically

myLinearLayout.addView(// Create the toolbar layout programmatically
        createToolbarLayout(););

没有布局的Android Studio工具栏

2 个答案: