Question

我试图在开关盒上设置一个单击侦听器，它将返回带有特定文本的自定义对话框，具体取决于具体情况。当我运行应用程序并单击负责显示具有特定结果的对话框的按钮时，应用程序崩溃。

当我检查调试器可能出现的错误时，它会转到我尝试更改对话框文本的行。例如：

gm.setText("result6");

Java代码

private void getHint(final int viewId) {
    int remainHints = Integer.parseInt(hintsValue.getText().toString());
    if (isHintUsed(viewId) != 1) {
        if (remainHints < 8) {
            final Dialog dialog = new Dialog(TestActivity.this);
            // Include dialog.xml file
            dialog.setContentView(R.layout.dialog);
            dialog.show();
            Button declineButton = (Button) dialog.findViewById(R.id.btn_cancel);
            // if decline button is clicked, close the custom dialog
            declineButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    // Close dialog
                    dialog.dismiss();
                }
            });



        }else {
            if (viewId == R.id.letter && isLetterHintOn == 1) {
                stopLetterHint();
            } else {
                final Dialog dialog = new Dialog(TestActivity.this);
                dialog.setContentView(R.layout.dialog);

                switch (viewId) {
                    case R.id.mom:
                        TextView mom = (TextView) findViewById(R.id.tv_description);
                        mom.setText("result 1");
                        break;
                    case R.id.dad:
                        TextView dad = (TextView) findViewById(R.id.tv_description);
                        dad.setText("result 2");
                        break;

                    case R.id.brother:
                        TextView brother = (TextView) findViewById(R.id.tv_description);
                        brother.setText("result 3");
                        break;

                    case R.id.sister:
                        TextView sis = (TextView) findViewById(R.id.tv_description);
                        sis.setText("result 4");
                        break;

                    case R.id.gfather:
                        TextView gf = (TextView) findViewById(R.id.tv_description);
                        gf.setText("result 5");
                        break;

                    case R.id.gmother:
                        TextView gm = (TextView) findViewById(R.id.tv_description);
                        gm.setText("result 6");
                        break;
                }

                Button videoButton = (Button) dialog.findViewById(R.id.btn_video);
                // if decline button is clicked, close the custom dialog
                videoButton.setOnClickListener(new View.OnClickListener() {

                    public void onClick(View view) {
                        if (viewId != R.id.letter) {
                            db.addUsedHint();
                            hintsValue.setText(String.valueOf(getHintsNumber()));
                        }
                        executeHint(viewId);
                    }

                });

                Button declineButton = (Button) dialog.findViewById(R.id.btn_cancel);
                // if decline button is clicked, close the custom dialog
                declineButton.setOnClickListener(new OnClickListener() {

                    public void onClick(View v) {
                    }

                });

                dialog.show();
            }

        }

    } else {
        executeHint(viewId);
    }

}

xml文件

 <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white">

<RelativeLayout
    android:id="@+id/rl_quit_learning"
    android:layout_width="match_parent"
    android:layout_height="150dp"
    android:background="@drawable/popup"
    android:paddingBottom="10dp"
    android:paddingLeft="10dp"
    android:paddingRight="10dp"
    android:paddingTop="10dp">

    <TextView
        android:id="@+id/tv_quit_learning"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_margin="10dp"
        android:textColor="#000"
        android:text="Quit LEarning?"
        android:textSize="20sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/tv_description"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/tv_quit_learning"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:layout_marginTop="10dp"
        android:textColor="#000"
        android:gravity="center"
        android:text="You are 400pts. away from \n unlocking rewards. Quit LEarning?"
        android:textSize="16sp" />
</RelativeLayout>

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="125dp"
    android:gravity="center"
    android:orientation="horizontal">

    <Button
        android:id="@+id/btn_cancel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/lock" />

    <Button
        android:id="@+id/btn_video"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/lock" />

</LinearLayout>

logcat的

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.momdad.family, PID: 18297
              java.lang.NullPointerException: Attempt to invoke virtual 
method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
                  at com.momdad.family
.TestActivity.getHint(TestActivity.java:1171)
                  at com.momdad.family
.TestActivity.access$200(TestActivity.java:67)
                  at com.momdad.family
.TestActivity$12.onClick(TestActivity.java:1059)
                  at android.view.View.performClick(View.java:5702)
                  at 
android.view.View$PerformClick.run(View.java:22533)
                  at android.os.Handler.handleCallback(Handler.java:739)
                  at android.os.Handler.dispatchMessage(Handler.java:95)
                  at android.os.Looper.loop(Looper.java:158)
                  at android.app.ActivityThread.main(ActivityThread.java:7224)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)

Answer 1

使用以下代码替换您的代码：

    switch (viewId) {
                case R.id.mom:
                    TextView mom = (TextView) dialog.findViewById(R.id.tv_description);
                    mom.setText("result 1");
                    break;
                case R.id.dad:
                    TextView dad = (TextView) dialog.findViewById(R.id.tv_description);
                    dad.setText("result 2");
                    break;

                case R.id.brother:
                    TextView brother = (TextView) dialog.findViewById(R.id.tv_description);
                    brother.setText("result 3");
                    break;

                case R.id.sister:
                    TextView sis = (TextView) dialog.findViewById(R.id.tv_description);
                    sis.setText("result 4");
                    break;

                case R.id.gfather:
                    TextView gf = (TextView) dialog.findViewById(R.id.tv_description);
                    gf.setText("result 5");
                    break;

                case R.id.gmother:
                    TextView gm = (TextView) dialog.findViewById(R.id.tv_description);
                    gm.setText("result 6");
                    break;
            }

SetOnClickListener用于自定义对话框切换案例

1 个答案: