安卓_页面传值示例

@Override
public void onClick(View v) {

   Intent intent = new Intent(this, MyActivity2.class);
   // 1.当你想打开一个界面,并且从新的界面获取数据时候,需要调用此方法
   // requestCode 请求码
   startActivityForResult(intent, 1);
}

public class MyActivity2 extends AppCompatActivity implements View.OnClickListener {

    private ImageView img1;
    private ImageView img2;
    private ImageView img3;
    private ImageView img4;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my2);


        img1 = findViewById(R.id.e1);
        img2 = findViewById(R.id.e3);
        img3 = findViewById(R.id.e2);
        img4 = findViewById(R.id.e4);

        img1.setOnClickListener(this);
        img2.setOnClickListener(this);
        img3.setOnClickListener(this);
        img4.setOnClickListener(this);
    }


    @Override
    public void onClick(View v) {
        Intent intent = new Intent();
        switch (v.getId()) {
            case R.id.e1:
                intent.putExtra("icon", R.mipmap.e0);
                break;
            case R.id.e3:
                intent.putExtra("icon", R.mipmap.e1);
                break;
            case R.id.e2:
                intent.putExtra("icon", R.mipmap.e2);
                break;
            case R.id.e4:
                intent.putExtra("icon", R.mipmap.e3);
                break;
        }
        // 给旧的页面传值
        setResult(0, intent);
        // 返回页面,如果没有这句,数据返不回去
        finish();
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    // 推荐使用resultCode
    if (data != null) {
        if requestCode == 1 {
            int iconResId = data.getIntExtra("icon", 0);
            imgV.setImageResource(iconResId);
        }
    }
}