如何从列表视图，并删除数据库中的一个项目 [英] how can i delete an item from listview and also database

问题描述

这是马program.in这个程序删除按钮有剪掉执行的onclick侦听器，请解决这个问题，或者我怎样才能获得一个特定项目的ID。

this is ma program.in this program on delete button there didnt perform onclick listener please solve this problem or how can i get the id of an particular item.

    delete = (Button) findViewById(R.id.delete);
    delete.setOnClickListener(this);
    if(v.equals(delete))
    { 
        new AlertDialog.Builder(ShareFolioEditActivity.this) 
         .setTitle("Delete")
     .setMessage("Are you sure ??? ")
             .setNeutralButton("no",null)
             .setPositiveButton("yes", new DialogInterface.OnClickListener() {
   public void onClick(DialogInterface dialog, int whichButton) {
     delete();                
    }
})      .show();

    }
}

public void delete()
{  
   db.delete("sharelist", "_id="+ID, null);
   Toast.makeText(this, "row deleted"+ID, Toast.LENGTH_SHORT).show();
   Bundle b=null;
   onCreate(b);
}

这是我的XML布局

  

<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
android:padding="10sp">

<TextView
android:id="@+id/category"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=""
android:layout_toRightOf="@+id/catagory"
 />
 </RelativeLayout>

请告诉我的解决方案

感谢

推荐答案

当您设置这个为的onClick 监听器按钮，还必须实现您的活动中的的onClick 方法。运行你的对话框，并执行删除操作的code将永远不会被调用你的情况。

When you set this as the onClick listener for a button, you must also implement the onClick method within your activity. The code that runs your dialog and performs the delete action will never be called in your case.

重新构建code到是这样的：

Refactor the code to something like:

    delete = (Button) findViewById(R.id.delete);
    delete.setOnClickListener(this);
}

public void onClick(View v)
{
    if(v.equals(delete))
    { 
        new AlertDialog.Builder(ShareFolioEditActivity.this) 
            .setTitle("Delete")
            .setMessage("Are you sure ??? ")
            .setNeutralButton("no",null)
            .setPositiveButton("yes", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {
                    delete();                
            }}).show();
    }
}

public void delete()
{  
    db.delete("sharelist", "_id="+ID, null);
    Toast.makeText(this, "row deleted"+ID, Toast.LENGTH_SHORT).show();
    Bundle b=null;
    onCreate(b);
}

请注意：我还没有选中此code，它可能无法编译，但它给你一个想法

Note: I've not checked this code, it might not compile, but it gives you an idea.

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