Question

我刚刚开始使用android但已经做了一些c＃，它看起来与java非常相似

简而言之，问题在于closeDialog方法

我对view / viewgroup不是很熟悉所以请不要用不正确的对象使用等来轰炸我。

简而言之，我正在创建一个简单的应用程序，我希望改进它（它基本上是一个巨大项目的开始）

_showhint对话框打开正常，并按预期显示“提示”，但closeDialog强制关闭应用程序，我不明白为什么

package com.example.app;

import android.app.Activity;
import android.app.Dialog;
import android.net.Uri;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
import android.webkit.ValueCallback;
import android.webkit.WebView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends ActionBarActivity {

    private WebView webView;
    final Activity activity = this;
    public Uri imageUri;

    private ValueCallback<Uri> mUploadMessage;
    private Uri mCapturedImageImageURI = null;
    private TextView lblAnswer, lblWelcome;
    private EditText edtInput;
    public TextView showText ;
    public Button btnShowHint, btnCalculate;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        edtInput = (EditText) findViewById(R.id.edtInput) ;
        lblWelcome = (TextView) findViewById(R.id.lblWelcome) ;
        lblAnswer = (TextView) findViewById(R.id.lblAnswer) ;
        btnShowHint = (Button) findViewById(R.id.btnHelp);
        btnCalculate = (Button) findViewById(R.id.btnShow) ;

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }
    }

    public  void calculate(View vw)
    {
        String [] arrEditStore = new String[edtInput.length()] ;
        String arrOperators [] = {"+", "-", "*", "/", "(", ")"} ;


    }

    public void _showhint(View vw)
    {
        final Dialog showHintDialog = new Dialog(activity);

        showHintDialog.setContentView(R.layout.custom_dialog);
        showHintDialog.setTitle("How to enter data");

        showHintDialog.show();
    }

    public void closeDialog(View vw)
    {
        final Dialog dialog = new Dialog(this) ;
        Button btnClose = (Button) dialog.findViewById(R.id.button) ;
        btnClose.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dialog.dismiss();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            return rootView;
        }
    }

}

编辑：将“this”添加到final Dialog dialog = new Dialog(this)

Answer 1

我发现了导致问题的原因

GIVEN CODE：

public void _showhint(View vw)
{
    final Dialog showHintDialog = new Dialog(activity);

    showHintDialog.setContentView(R.layout.custom_dialog);
    showHintDialog.setTitle("How to enter data");

    showHintDialog.show();
}

public void closeDialog(View vw)
{
    final Dialog dialog = new Dialog(this) ;
    Button btnClose = (Button) dialog.findViewById(R.id.button) ;
    btnClose.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            dialog.dismiss();
        }
    });
}

<强> SOULTION

首先，我将btnClose的decleration移到了顶部

public Button btnShowHint, btnCalculate, btnClose;

然后在设计视图中，删除按钮的链接关闭onclick方法，参考closeDialog。

然后，完全删除closeDialog方法，并将部分代码移动到_showHint方法

它也具有逻辑意义，感谢@Mike M.对帖子发表评论，帮我推理出来，因为我说，这个按钮必须关闭对话框但是在这个按钮的方法中，我将它分配给单独使用，它根本没有逻辑意义，这里是改变的代码，它的工作原理

更改代码：

public void _showhint(View vw)
    {
        final Dialog showHintDialog = new Dialog(activity);

        showHintDialog.setContentView(R.layout.custom_dialog);
        showHintDialog.setTitle("How to enter data");

        showHintDialog.show();
        btnClose = (Button) showHintDialog.findViewById(R.id.button) ;
        btnClose.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                showHintDialog.dismiss();
            }
        });
    }

我们有时会犯愚蠢和不合时宜的错误，有些比其他人更糟糕，但是如果你找到了解决问题的方法，也许某个人有同样的问题，那么就可以解决你的问题，这可能有所帮助那个人!!!

欢呼声

使用custom_dialog.dismiss（）强制关闭应用程序

1 个答案: