Question

我做了一个通用的布局，在每个活动中包含V7工具栏，并使用它的公共类文件CommonToolbar.java来处理它的属性。

layout_common_toolbar.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar_common"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="@dimen/abc_action_bar_default_height_material"
    android:background="?attr/colorPrimaryDark"/>

CommonToolbar.java

public class CommonToolbar {

    Activity activity;
    Toolbar toolbar;

    CommonToolbar(Activity activity, View view, String title) {
        super();
        this.activity = activity;
        toolbar = (Toolbar)view.findViewById(R.id.toolbar_common);
        toolbar.setTitle(title);
        toolbar.setTitleTextColor(activity.getResources().getColor(R.color.white));
    }

    void setNav() {
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                activity.onBackPressed();
            }
        });
    }

    void setMenuListner() {
        toolbar.setOnMenuItemClickListener(new Toolbar.OnMenuItemClickListener() {
            @Override
            public boolean onMenuItemClick(MenuItem item) {
                switch (item.getItemId()) {
                /*  case R.id.searchItem:
                        Toast.makeText(getApplicationContext(), "Search", Toast.LENGTH_SHORT).show();
                        break;
                    case R.id.filterItem:
                        Toast.makeText(getApplicationContext(), "Filter", Toast.LENGTH_SHORT).show();
                    break;*/
                }

                return true;
            }
        });

        toolbar.inflateMenu(R.menu.common_toolbar_menu);
    }
}

使用它像：

布局

<include  android:layout_height="@dimen/abc_action_bar_default_height_material"
              android:id="@+id/includeSurgicalDetail"
              android:layout_width="match_parent"
              layout="@layout/layout_common_actionbar"/>

活动

View includedLayout = findViewById(R.id.includeSurgicalDetail);
CommonToolbar commonToolbar = new CommonToolbar(SurgicalDetail.this, includedLayout, pName);
commonToolbar.setMenuListner();
commonToolbar.setNav();

但是我收到以下错误：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.greyline.eswasthyaprojectv3/com.eswasthyaV3.SurgicalDetail}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.Toolbar.setTitle(java.lang.CharSequence)' on a null object reference

Answer 1

如果您不想编写相同的选项菜单代码，则应extend改为Activity。

写一个BaseActivity类，如：

public class BaseActivity extends Activity{
    protected Toolbar toolbar;
    public void onCreate(Bundle savedInstaceState){
        super.onCreate(savedInstanceState);

        //initialize the Toolbar, set the menu listener, nav, etc
        toolbar = (Toolbar)findViewById(R.id.toolbar_common);
    }
}

然后，对于您希望拥有共享代码的所有Activity，请展开BaseActivity而不是Activity。因此，您不需要反复编写相同的选项菜单代码。

包括appcompact v7工具栏错误

1 个答案: