新建一个XML文件，文件名为layout_custom_dialog

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:gravity="center_horizontal"android:orientation="vertical"android:background="@drawable/bg_custom_dialog"><TextViewandroid:id="@+id/tv_title"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="提示"android:textSize="20sp"android:textStyle="bold" /><TextViewandroid:id="@+id/tv_message"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="删除？"android:textSize="20sp"android:textStyle="bold" /><Viewandroid:layout_width="match_parent"android:layout_height="1dp"android:background="@color/black"/><LinearLayoutandroid:layout_width="match_parent"android:layout_height="40dp"android:orientation="horizontal"><TextViewandroid:id="@+id/tv_no"android:layout_width="0dp"android:layout_height="match_parent"android:layout_weight="1"android:text="取消"android:textSize="20sp"android:textStyle="bold"android:gravity="center"/><Viewandroid:layout_width="1dp"android:layout_height="match_parent"android:background="@color/black"/><TextViewandroid:id="@+id/tv_ok"android:layout_width="0dp"android:layout_height="match_parent"android:layout_weight="1"android:text="确定"android:textSize="20sp"android:textStyle="bold"android:gravity="center"/></LinearLayout>></LinearLayout>

在drawable文件下新建XML文件，文件名为bg_custom_dialog，定义了圆角

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"android:shape="rectangle"><corners android:radius="10dp"/><solid android:color="@color/white"/>
</shape>

新建CustomDialog的类

public class CustomDialog extends Dialog implements View.OnClickListener {private TextView mTitle,mTvMessage,mConfirm,mCancel;private String title,message,confirm,cancel;private OnCancellistener cancellistener;private OnConfirmlistener confirmlistener;//先写构造方法public CustomDialog(@NonNull Context context) {super(context);}public CustomDialog(@NonNull Context context, int themeResId) {super(context, themeResId);}public void setTitle(String title) {this.title = title;}public void setMessage(String message) {this.message = message;}public void setConfirm(String confirm,OnConfirmlistener listener) {this.confirm = confirm;this.confirmlistener=listener;}public void setCancel(String cancel,OnCancellistener listener) {this.cancel = cancel;this.cancellistener=listener;}@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.layout_custom_dialog);//设置宽度WindowManager manager= getWindow().getWindowManager();Display display=manager.getDefaultDisplay();WindowManager.LayoutParams params=getWindow().getAttributes();Point size=new Point();display.getSize(size);params.width=(int)(size.x*0.8);getWindow().setAttributes(params);//实现圆角getWindow().setBackgroundDrawableResource(R.drawable.bg_custom_dialog);mTitle=(TextView) findViewById(R.id.tv_title);mTvMessage=(TextView) findViewById(R.id.tv_message);mConfirm=(TextView) findViewById(R.id.tv_ok);mCancel=(TextView) findViewById(R.id.tv_no);if(TextUtils.isEmpty(title)){mTitle.setText(title);}if(TextUtils.isEmpty(message)){mTvMessage.setText(message);}if(TextUtils.isEmpty(title)){mConfirm.setText(confirm);}if(TextUtils.isEmpty(title)){mCancel.setText(cancel);}mConfirm.setOnClickListener(this);mCancel.setOnClickListener(this);}@Overridepublic void onClick(View view) {switch (view.getId()){case R.id.tv_no:if(cancellistener!=null){cancellistener.onCancel(this);}dismiss();break;case R.id.tv_ok:if(confirmlistener!=null){confirmlistener.onConfirm(this);}dismiss();break;}}public interface OnConfirmlistener{void onConfirm(CustomDialog dialog);}public interface OnCancellistener{void onCancel(CustomDialog dialog);}
}

在MainActivity里实现CustomDialog这个类

public class MainActivity extends AppCompatActivity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Button mBtn_Dialog=(Button) findViewById(R.id.dialog);mBtn_Dialog.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {CustomDialog customDialog=new CustomDialog(MainActivity.this);customDialog.setTitle("提示");customDialog.setMessage("删除？");customDialog.setConfirm("确认", new CustomDialog.OnConfirmlistener() {@Overridepublic void onConfirm(CustomDialog dialog) {}});customDialog.setCancel("取消", new CustomDialog.OnCancellistener() {@Overridepublic void onCancel(CustomDialog dialog) {}});customDialog.show();}});}
}