Question

我已经经历了很多关于将主要ID从一个表传递到新活动的其他帖子，我尝试了几种不同的方法而没有任何成功。我目前认为我正在传递它，但实际上没有任何内容出现在下一个Activity中。以下是我想要完成的内容的概要。

如果用户创建新联盟，则会获得主要ID（1）。用户单击新创建的联盟，现在他们可以选择创建保龄球。当然，Bowler可以属于许多联赛，所以我希望能够将联盟ID写入Bowler牌桌，这样我就可以选择仅仅联赛Id = 1并且仅显示与联盟相关联的投球手。

MainActivity

//On Long Click On The RecyclerView Item An Alert Dialog Is Opened With The Option To Choose Edit/Delete
        recyclerView.addOnItemTouchListener(new RecyclerTouchListener(this,
                recyclerView, new RecyclerTouchListener.ClickListener() {
            @Override
            public void onClick(View view, final int position) {



                int leagueId = leaguesList.get( position ).getId();
                Intent myIntent = new Intent(getBaseContext(), Main2Activity.class);
                myIntent.putExtra("value1", leagueId);
                startActivity(myIntent);
                //Intent myIntent = new Intent(getApplicationContext(), BowlerActivity.class);
                //startActivity(myIntent);

            }

            @Override
            public void onLongClick(View view, int position) {
                showActionsDialog(position);
            }
        }));
    }

Main2Activity

public class Main2Activity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );
        setContentView( R.layout.league_id );
        Toolbar toolbar = (Toolbar) findViewById( R.id.toolbar );
        setSupportActionBar( toolbar );

        String savedExtra = getIntent().getStringExtra( "value1" );
    TextView myText = (TextView) findViewById(R.id.tvLeagueId);
        final String s = myText.toString();
        myText.setText(savedExtra);


    }

}

联赛班级

public static final String TABLE_NAME = "leagues";

        public static final String COLUMN_ID = "_id";
        public static final String COLUMN_NAME = "name";
        public static final String COLUMN_TIMESTAMP = "timestamp";

        private int id;
        private String name;
        private String timestamp;


        // Create table SQL query
        public static final String CREATE_TABLE =
                "CREATE TABLE " + TABLE_NAME + "("
                        + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
                        + COLUMN_NAME + " TEXT,"
                        + COLUMN_TIMESTAMP + " DATETIME DEFAULT CURRENT_TIMESTAMP"
                        + ")";

        public League() {
        }

        public League(int id, String name, String timestamp) {
            this.id = id;
            this.name = name;
            this.timestamp = timestamp;
        }

        public int getId() {
            return id;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public String getTimestamp() {
            return timestamp;
        }

        public void setId(int id) {
            this.id = id;
        }

        public void setTimestamp(String timestamp) {
            this.timestamp = timestamp;
        }
}

保龄球课

public static final String TABLE_NAME = "Bowlers";

public static final String COLUMN_ID = "_id";
public static final String COLUMN_LEAGUE_ID = "league_id";
public static final String COLUMN_NAME = "name";
public static final String COLUMN_TIMESTAMP = "timestamp";

private int id;
private int league_id;
private String name;
private String timestamp;


// Create table SQL query
public static final String CREATE_TABLE =
        "CREATE TABLE " + TABLE_NAME + "("
                + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
                + COLUMN_LEAGUE_ID + " INTEGER,"
                + COLUMN_NAME + " TEXT,"
                + COLUMN_TIMESTAMP + " DATETIME DEFAULT CURRENT_TIMESTAMP"
                + ")";

public Bowler() {
}

public Bowler(int id, int league_id, String name, String timestamp) {
    this.id = id;
    this.league_id = league_id;
    this.name = name;
    this.timestamp = timestamp;
}

public int getId() {
    return id;
}

public int getLeagueId() {return league_id;}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getTimestamp() {
    return timestamp;
}

public void setId(int id) {
    this.id = id;
}

public void setLeagueId(int league_id) {
    this.league_id = league_id;
}

public void setTimestamp(String timestamp) {
    this.timestamp = timestamp;
}

}

非常感谢任何指导。

Answer 1

我相信你的问题是你要发送一个整数但是试图获取一个字符串，当你应该检索一个整数时。因此你应该使用： -

public class Main2Activity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );
        setContentView( R.layout.league_id );
        Toolbar toolbar = (Toolbar) findViewById( R.id.toolbar );
        setSupportActionBar( toolbar );

        //String savedExtra = getIntent().getStringExtra( "value1" ); <<<< COMMENTED OUT
        String savedextra = String.valueOf(getIntent().getIntExtra("value1",-1)); //<<<< ADDED
    TextView myText = (TextView) findViewById(R.id.tvLeagueId);
        final String s = myText.toString();
        myText.setText(savedExtra);
    }
}

即。 String savedextra = String.valueOf(getIntent().getIntExtra("value1",-1));代替String savedExtra = getIntent().getStringExtra( "value1" );

注意 -1 将是返回的值，如果没有此类意图，则不对应 id （1或更大），因此-1表示无效的 ID 即可。
- 注意ID理想情况下应长，因为它们最多可达9223372036854775807，而2147483647则是 int 的限制。

将ID字段写入另一个表中以进行ListView过滤

1 个答案: