1, Anonymous internal mode

This method seems simple and easy to understand on the whole, and is commonly used by individuals

xml layout

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.button.MainActivity" >
 
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />
 
</LinearLayout>

java code

public class MainActivity extends Activity {
 
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		// Find button control
		Button button = (Button) findViewById(R.id.button);
		// Setting click event in anonymous internal mode
		button.setOnClickListener(new OnClickListener() {
 
			@Override
			public void onClick(View v) {
				//Display the prompt Toast on the screen
				Toast.makeText(MainActivity.this, "Anonymous internal mode", Toast.LENGTH_SHORT).show();
			}
		});
	}
}

When multiple controls need to implement event listening, it can be seen that anonymous objects are extracted to avoid resource consumption by creating objects multiple times

public class MainActivity extends Activity {
 
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		// 1. Find the button control
		Button button = (Button) findViewById(R.id.button);
		// 3. Set button click event
		button.setOnClickListener(onClickListener);
	}
	// 2. Get OnClickListener object
	OnClickListener onClickListener = new OnClickListener() {
 
		@Override
		public void onClick(View v) {
			// You can use switch to set different buttons to prompt different contents by matching the control id
			// view.getId() gets the id of the clicked control
			switch (v.getId()) {
			case R.id.button:
				Toast.makeText(MainActivity.this, "Different content can be set using", Toast.LENGTH_SHORT).show();
				break;
			case 2:
				// ellipsis
				break;
			default:
				break;
			}
		}
	};
}

2, Implement OnClickListener interface and rewrite onClick method

This method is suitable for multiple controls to implement click event monitoring

public class MainActivity extends Activity implements OnClickListener{
 
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		// 1. Find the button control
		Button button = (Button) findViewById(R.id.button);
		// 3. Button setting click event
		button.setOnClickListener(this);
	}
 
	@Override
	public void onClick(View v) {
		// 2. Implement the OnClickListener interface and override the onClick method
		Toast.makeText(MainActivity.this, "Realization OnClickListener", Toast.LENGTH_SHORT).show();		
	}
}

This method can also create a class to implement the OnClickListener interface

public class MainActivity extends Activity {
 
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		// 1. Find the button control
		Button button = (Button) findViewById(R.id.button);
		// 3. Button setting click event
		button.setOnClickListener(new myOnclickLister());
	}
	
	// 2. Create your own class to implement the OnClickListener interface, and then override the onClick method
	class myOnclickLister implements OnClickListener {
 
		@Override
		public void onClick(View v) {
			Toast.makeText(MainActivity.this, "Realization OnClickListener", Toast.LENGTH_SHORT).show();
		}
	}
}

3, OnClick property of XML settings button

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.button.MainActivity" >
 
    <Button
        android:onClick="btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />
 
</LinearLayout>

Then in java code, the method to establish the corresponding name of onClick property

public class MainActivity extends Activity {
 
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
	}
	//Define the method corresponding to the XML OnClick attribute name. Note that add View v to the method parameter
	public void btn(View v) {
		Toast.makeText(MainActivity.this, "Set up Onclick attribute", Toast.LENGTH_SHORT).show();
	}
}

Although this method is very convenient and the code is simple, it is not easy for others to understand the aspect naming problem, and it is not used in multiple controls.