不可转换的类型;无法将'android.app.Fragment'强制转换为'hk.ust.cse.omp107x.fragmentspractice'

时间:2018-03-17 19:57:10

标签: java android android-fragments

感谢是否有人可以提供帮助。

我的目标是将变量从活动传递到片段。 我试图在textview中显示所选单选按钮的文本(在活动中)(在同一活动中显示的片段中)。 我在行“BlankFragment bf =(BlankFragment)getFragmentManager()。findFragmentById(R.id.blankfragment);”中看到了上述错误。

我的mainactivity.java文件如下:

    g = 0
temp = len(koord)
print(temp)
while g != temp:
    (value1,x1,y1,a) = koord[g]
    for i in range(g,temp - 1):
        (value2,x2,y2,b) = koord[i+1]
        if y1 >= y2 + b or y2 >= y1 + a:
            diff[abs(value1 - value2)].append([value1,value2])
        if x1 >= x2 + b or x2 >= x1 + a:
            diff[abs(value1 - value2)].append([value1,value2])
    g += 1

我的fragment.java文件如下:

package hk.ust.cse.comp107x.fragmentspractice;

import android.annotation.SuppressLint;
import android.support.v4.app.Fragment;
import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        RadioGroup rg = (RadioGroup) findViewById(R.id.radioGroup);
        rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                /*RadioButton rb = (RadioButton) findViewById(checkedId);
                String string = rb.getText().toString();
                Log.d("demo", string);*/
                BlankFragment bf = (BlankFragment) getFragmentManager().findFragmentById(R.id.blankfragment);
                if (checkedId == R.id.radioButton) {
                    bf.changecolor(Color.RED);
                } else if (checkedId == R.id.radioButton2) {
                    bf.changecolor(Color.BLUE);
                } else if (checkedId == R.id.radioButton3) {
                    bf.changecolor(Color.GREEN);
                } else if (checkedId == R.id.radioButton4) {
                    bf.changecolor(Color.YELLOW);
                }
            }
        });
    }
}

我的main_activity.xml如下:

package hk.ust.cse.comp107x.fragmentspractice;


import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;


/**
 * A simple {@link Fragment} subclass.
 */
public class BlankFragment extends Fragment {


    public BlankFragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_blank, container, false);
    }

    public void changecolor(int Color){
        getActivity().findViewById(R.id.relative).setBackgroundColor(Color);
    }
}

我的fragment.xml如下:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="hk.ust.cse.comp107x.fragmentspractice.MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/fragment"
        android:layout_alignParentEnd="true"
        android:layout_marginBottom="31dp"
        android:layout_marginEnd="75dp"
        android:text="@string/displaytextview" />

    <RadioGroup
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/radioGroup">

        <RadioButton
            android:id="@+id/radioButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="@string/redvalue" />

        <RadioButton
            android:id="@+id/radioButton2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="@string/bluevalue" />

        <RadioButton
            android:id="@+id/radioButton3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="@string/greenvalue" />

        <RadioButton
            android:id="@+id/radioButton4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="@string/yellowvalue" />

    </RadioGroup>

    <fragment
        android:id="@+id/blankfragment"
        android:name="hk.ust.cse.comp107x.fragmentspractice.BlankFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/radioGroup"
        android:layout_centerHorizontal="true"
        tools:layout="@layout/fragment_blank"/>
</RelativeLayout>

0 个答案:

没有答案