Android“最佳实践”从对话框返回值

Android最佳实践：从对话框返回值

java
public class MyDialogFragment extends DialogFragment {
    private OnDialogResultListener mListener;
    // 定义回调接口
    public interface OnDialogResultListener {
        void onPositiveResult(String result);
        void onNegativeResult();
    }
    // 设置回调接口
    public void setOnDialogResultListener(OnDialogResultListener listener) {
        mListener = listener;
    }
    @NonNull
    @Override
    public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
        AlertDialog.Builder builder = new AlertDialog.Builder(requireContext());
        builder.setTitle("提示")
                .setMessage("确定要执行此操作吗？")
                .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        if (mListener != null) {
                            mListener.onPositiveResult("确认");
                        }
                    }
                })
                .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        if (mListener != null) {
                            mListener.onNegativeResult();
                        }
                    }
                });
        return builder.create();
    }
}

java
public class MainActivity extends AppCompatActivity implements MyDialogFragment.OnDialogResultListener {
    private static final String DIALOG_TAG = "MyDialog";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 创建对话框实例
        MyDialogFragment dialogFragment = new MyDialogFragment();
        // 设置回调接口
        dialogFragment.setOnDialogResultListener(this);
        // 显示对话框
        dialogFragment.show(getSupportFragmentManager(), DIALOG_TAG);
    }
    @Override
    public void onPositiveResult(String result) {
        // 处理确认结果
        Toast.makeText(this, "确认操作：" + result, Toast.LENGTH_SHORT).show();
    }
    @Override
    public void onNegativeResult() {
        // 处理取消结果
        Toast.makeText(this, "取消操作", Toast.LENGTH_SHORT).show();
    }
}