Question

我为onBackPressed创建了一个新的布局名称dialog_exit但是当我安装并打开时，我的应用程序无法打开并显示错误关闭app 请查看我的整个代码并指导我如何解决此问题这是我的主要活动代码

public class MainActivity extends AppCompatActivity {

    public Dialog mDialog;
    public Button mDialogyes, mDialogno;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        createDialog();
    }

    private void createDialog() {
        mDialog = new Dialog(this);
        mDialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
        mDialog.setContentView(R.layout.dialog_exit);
        mDialog.setCanceledOnTouchOutside(true);
        mDialog.setCancelable(true);
        mDialogyes = (Button) findViewById(R.id.yes);
        mDialogno = (Button) findViewById(R.id.no);

        mDialogyes.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(Intent.ACTION_MAIN);
                intent.setFlags(intent.FLAG_ACTIVITY_CLEAR_TOP);
                intent.addCategory(Intent.CATEGORY_HOME);
                startActivity(intent);
                finish();
                System.exit(0);

                mDialogno.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        mDialog.dismiss();
                    }
                });
            }

        });

    }
    @Override
    public void onBackPressed() {
        mDialog.show();
    }
}

这是我的布局代码截图，因为

stackoverflow not allow me to add more code that why sharing image

Answer 1

更新了createDialog函数的代码

 private void createDialog() {
    mDialog = new Dialog(this);
    mDialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
    mDialog.setContentView(R.layout.dialog_exit);
    mDialog.setCanceledOnTouchOutside(true);
    mDialog.setCancelable(true);
    mDialogyes = (Button) mDialog.findViewById(R.id.yes);
    mDialogno = (Button) mDialog.findViewById(R.id.no);

    mDialogyes.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(Intent.ACTION_MAIN);
            intent.setFlags(intent.FLAG_ACTIVITY_CLEAR_TOP);
            intent.addCategory(Intent.CATEGORY_HOME);
            startActivity(intent);
            finish();
            System.exit(0);

        }

    });

    mDialogno.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mDialog.dismiss();
        }
    });

}

Answer 2

try this code 
       mDialogyes = (Button)mDialogyes. findViewById(R.id.yes);
        mDialogno = (Button)mDialogyes. findViewById(R.id.no);

    mDialogyes.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(Intent.ACTION_MAIN);
                intent.setFlags(intent.FLAG_ACTIVITY_CLEAR_TOP);
                intent.addCategory(Intent.CATEGORY_HOME);
                startActivity(intent);
                finish();
                System.exit(0);


            }

        });

           mDialogno.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        mDialog.dismiss();
                    }
                });

Answer 3

你必须这样做

mDialogyes = (Button) mDialog.findViewById(R.id.yes);
mDialogno = (Button) mDialog.findViewById(R.id.no);

onBackPressed的createDialog，但我的应用程序显示错误关闭应用程序

3 个答案: