是否有任何解决方案可以在不同的方法中仅使用 1 个 findViewById

Question

I have 2 different methods.

Method a will display textview1. Method b will also display textview1.

In both the methods, I need to include findViewById(R.id.textview1). Thus need to put twice findViewById in the code.

Answer 1

// if you are using Kotlin, apply this plugin with the kotlin library in your app Module Gradle

apply plugin: 'kotlin-kapt'

kapt {
    generateStubs = true
}

// then you can just give the name of the view in the XML layout and you dont have to initialize the view eg ..

// xml view

<TextView
                        android:id="@+id/tv_location"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"

                        android:gravity="center_vertical"
                        android:paddingStart="8dp"
                        android:singleLine="true"

                        android:textSize="14sp" />

// now in the kotlin class

tv_location.text = "Kolkata,India" 

//try this 

Answer 2

Use butterknife library:

class Activity {
    @BindView(R.id.textview1)
    TextView view1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.setContentView(R.layout.activity_home);
        ButterKnife.bind(this);
    }

You can now access view1 in any methods in this activity.

Answer 3

You can declare your textview as global variable. Then you can use that variable anywhere in that activity or class or fragment.

public class Main2Activity extends AppCompatActivity {

   private TextView textView1;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main2);
      textView1 = findViewById(R.id.textview1);
   }
   private void method1(){
      textView1.setText("method 1");
   }
   private void method2(){
      textView1.setText("method 2");
   }
}

Answer 4

ButterKnife is developed by Jake Wharton at Square and is essentially used to save typing repetitive lines of code like findViewById(R.id.view) when dealing with views, thus making our code look a lot cleaner.

add this dependency into your build.gradle

compile 'com.jakewharton:butterknife:6.1.0'

write this on onCreate()

ButterKnife.bind(this);

and than you can find you elements like this :

@Bind(R.id.txtview1)
Textview textview;