在Android中以编程方式在相对布局中添加多个相对布局

时间：2013-07-08 09:52:44

标签： android android-layout relativelayout android-view layoutparams

我正在尝试创建RelativeLayout容器框以在其中包含元素并以编程方式将它们创建为RelativeLayout。代码工作正常，没有将元素放在RelativeLayout容器中，但是当我将它们放入时会崩溃应用程序。

以下是代码，有人可以帮我弄清楚我做错了什么并且需要做些什么来解决这个问题：

layout = new RelativeLayout(this);

    RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
    RelativeLayout.LayoutParams textParams1 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    RelativeLayout.LayoutParams textParams2 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    RelativeLayout.LayoutParams textParams3 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    RelativeLayout.LayoutParams textParams4 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    RelativeLayout.LayoutParams progressParams1 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    RelativeLayout.LayoutParams imageButtonParams1 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    RelativeLayout.LayoutParams containerParams1 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, dpContainerHeight);
    RelativeLayout.LayoutParams containerParams2 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, dpContainerHeight);

    layout.setPadding(dpMargin, dpMargin, dpMargin, dpMargin);

    tv1 = new TextView(this);
    textParams1.addRule(RelativeLayout.ALIGN_PARENT_TOP);
    textParams1.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
    tv1.setId(1);
    tv1.setText("TextView1");

    tv2 = new TextView(this);
    textParams2.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
    textParams2.addRule(RelativeLayout.BELOW, tv1.getId());
    textParams2.setMargins(0, 0, 0, dpMargin);
    tv2.setId(2);
    tv2.setText("TextView2");

    containerLayout1 = new RelativeLayout(this);
    containerParams1.addRule(RelativeLayout.ALIGN_LEFT, tv2.getId());
    containerParams1.addRule(RelativeLayout.ALIGN_RIGHT, tv1.getId());
    containerParams1.addRule(RelativeLayout.BELOW, tv2.getId());
    containerParams1.setMargins(0, 0, 0, dpMargin);
    containerLayout1.setId(3);
    containerLayout1.setBackgroundResource(R.color.display_panels);

    containerLayout2 = new RelativeLayout(this);
    containerParams2.addRule(RelativeLayout.ALIGN_LEFT, containerLayout1.getId());
    containerParams2.addRule(RelativeLayout.ALIGN_RIGHT, containerLayout1.getId());
    containerParams2.addRule(RelativeLayout.BELOW, containerLayout1.getId());
    containerParams2.setMargins(0, 0, 0, dpMargin);
    containerLayout2.setId(4);
    containerLayout2.setBackgroundResource(R.color.display_panels);

    tv3 = new TextView(this);
    textParams3.addRule(RelativeLayout.ABOVE, tv4.getId());
    textParams3.addRule(RelativeLayout.ALIGN_LEFT, pb1.getId());
    tv3.setId(5);
    tv3.setText("TextView3");
    tv3.setTextAppearance(this, android.R.attr.textAppearanceSmall);

    tv4 = new TextView(this);
    textParams4.addRule(RelativeLayout.ABOVE, pb1.getId());
    textParams4.addRule(RelativeLayout.CENTER_HORIZONTAL);
    tv4.setId(6);
    tv4.setText("TextView4");
    tv4.setTextAppearance(this, android.R.attr.textAppearanceSmall);

    pb1 = new ProgressBar(this);
    progressParams1.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
    progressParams1.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
    progressParams1.addRule(RelativeLayout.LEFT_OF, ib1.getId());
    pb1.setId(7);
    pb1.setProgress(40);
    pb1.setMax(100);

    ib1 = new ImageButton(this);
    imageButtonParams1.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
    imageButtonParams1.addRule(RelativeLayout.ALIGN_TOP, pb1.getId());
    ib1.setId(8);
    ib1.setBackgroundResource(R.color.display_panels);
    ib1.setImageResource(R.drawable.ic_green_ok);

    layout.addView(tv1, textParams1);
    layout.addView(tv2, textParams2);
    containerLayout1.addView(tv3, textParams3);
    containerLayout1.addView(tv4, textParams4);
    containerLayout1.addView(pb1, progressParams1);
    containerLayout1.addView(ib1, imageButtonParams1);
    layout.addView(containerLayout1, containerParams1);
    layout.addView(containerLayout2, containerParams2);
    setContentView(layout, layoutParams);

这是logcat：

07-08 11:44:31.926: E/AndroidRuntime(7533): FATAL EXCEPTION: main
07-08 11:44:31.926: E/AndroidRuntime(7533): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.mobileapplicationretry/com.example.mobileapplicationretry.TestContainerActivity}: java.lang.NullPointerException
07-08 11:44:31.926: E/AndroidRuntime(7533):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at android.os.Looper.loop(Looper.java:137)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at android.app.ActivityThread.main(ActivityThread.java:5041)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at java.lang.reflect.Method.invokeNative(Native Method)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at java.lang.reflect.Method.invoke(Method.java:511)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at dalvik.system.NativeStart.main(Native Method)
07-08 11:44:31.926: E/AndroidRuntime(7533): Caused by: java.lang.NullPointerException
07-08 11:44:31.926: E/AndroidRuntime(7533):     at com.example.mobileapplicationretry.TestContainerActivity.onCreate(TestContainerActivity.java:72)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at android.app.Activity.performCreate(Activity.java:5104)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
07-08 11:44:31.926: E/AndroidRuntime(7533):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
07-08 11:44:31.926: E/AndroidRuntime(7533):     ... 11 more

2 个答案:

答案 0 :(得分：1)

你要求从视图中获取你尚未创建的id（tv4.ge​​tId（））;

答案 1 :(得分：1)

高达tv3代码非常完美，现在需要更改以下代码。 

    tv3 = new TextView(this);
    tv3.setId(5);
    tv3.setText("TextView3");
    tv3.setTextAppearance(this, android.R.attr.textAppearanceSmall);

    tv4 = new TextView(this);

    tv4.setId(6);
    tv4.setText("TextView4");
    tv4.setTextAppearance(this, android.R.attr.textAppearanceSmall);

    pb1 = new ProgressBar(this);

    pb1.setId(7);
    pb1.setProgress(40);
    pb1.setMax(100);


    ib1 = new ImageButton(this);
    imageButtonParams1.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
    imageButtonParams1.addRule(RelativeLayout.ALIGN_TOP, pb1.getId());
    ib1.setId(8);
    ib1.setBackgroundResource(R.color.display_panels);
    ib1.setImageResource(R.drawable.ic_green_ok);

    progressParams1.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
    progressParams1.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
    progressParams1.addRule(RelativeLayout.LEFT_OF, ib1.getId());
    textParams4.addRule(RelativeLayout.ABOVE, pb1.getId());
    textParams4.addRule(RelativeLayout.CENTER_HORIZONTAL);
    textParams3.addRule(RelativeLayout.ABOVE, tv4.getId());
    textParams3.addRule(RelativeLayout.ALIGN_LEFT, pb1.getId());


    layout.addView(tv1, textParams1);
    layout.addView(tv2, textParams2);
    containerLayout1.addView(tv3, textParams3);
    containerLayout1.addView(tv4, textParams4);
    containerLayout1.addView(pb1, progressParams1);
    containerLayout1.addView(ib1, imageButtonParams1);
    layout.addView(containerLayout1, containerParams1);
    layout.addView(containerLayout2, containerParams2);
    setContentView(layout, layoutParams);

当你将获得空指针异常时我已经改变了。我希望它对你有帮助。

相关问题
最新问题