Question

我需要导航到之前的活动。我想使用操作栏的箭头（工具栏）。我无法在操作栏（工具栏）中看到向上箭头。我附上下面的活动代码。

ImageActivity.java

public class ImageActivity extends AppCompatActivity {

    private Toolbar toolbar;
    int img,img1;
    String text;
    ImageView imgicon;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        getWindow().requestFeature(Window.FEATURE_ACTION_BAR);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_image);

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().show();
        Drawable upArrow = ContextCompat.getDrawable(this, R.drawable.abc_ic_ab_back_mtrl_am_alpha);
        upArrow.setColorFilter(ContextCompat.getColor(this, R.color.white), PorterDuff.Mode.SRC_ATOP);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeAsUpIndicator(upArrow);
        getSupportActionBar().setHomeButtonEnabled(true);


        imgicon = (ImageView) findViewById(R.id.img);

        Bundle bundle =  getIntent().getExtras();

        if(bundle!=null)
        {
        img = bundle.getInt("img");
        text = bundle.getString("Phone");
        getSupportActionBar().setTitle("text");
        imgicon.setImageResource(img);
        }

        img1 = bundle.getInt("img1");
        imgicon.setImageResource(img1);

    }


    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                //Write your logic here
                this.finish();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }
}

有没有人遇到过这种情况，并以某种方式找到了解决问题的方法？提前谢谢。

Answer 1

请尝试使用此

android.support.v7.widget.Toolbar toolbar = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar);

        try {
            setSupportActionBar(toolbar);

            ActionBar actionbar = getSupportActionBar();
            if (actionbar != null) {
                actionbar.setHomeButtonEnabled(true);
                actionbar.setDisplayShowHomeEnabled(true);
                actionbar.setDisplayHomeAsUpEnabled(true);
            }

并在XML中使用它

<android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="@color/colorWhite"
        app:popupTheme="@style/AppTheme.PopupOverlay" />

Answer 2

我的解决方案：

// Show the Up button in the action bar.
    ActionBar actionBar = getSupportActionBar();
    if (actionBar != null) {
        actionBar.setDisplayHomeAsUpEnabled(true);
    }

为什么我无法在操作栏中看到向上箭头？

2 个答案: